Sunday, 19 June 2022
Pre-Conference Workshop

Workshop 1: Modern Design-Based Statistical Methods for Environmental Epidemiology

Time: 9:00 - 12:00


Asst Prof Jonathan Huang
Singapore Institute for Clinical Sciences, A*STAR

Assoc Prof Tarik Benmarhnia
University of California, San Diego

This workshop will introduce students to modern design-based approaches to estimate effects from observational or non-experimental data with relevance to environmental epidemiology. The audience will overview counterfactuals and how they relate to inferring effects from data and analytic design approaches including target trials, negative controls, and quasi-experimental with broad relevance to studies on pollutants, molecular mechanisms, climate change, environmental policy, and more.

Workshop 2: Improve personal brand to leverage networking relationships (Pre-conference)

Time: 13:00 - 15:00


Julia Palmer
Relational Strategist & Founder, Relatus

Great opportunities are found in great networks.

This session will focus on personal branding and how to promote yourself within your network (both existing and potential).

Having the confidence to connect with people when first meeting them is vital for your personal and professional success. The next step is managing those relationships to ensure they are sustained and mutually beneficial.

  • Explore the 4 types of networking and decide which one will ensure networking works for you (long term)
  • Learn 3 critical steps to help you create and manage a more viable network and truly connect with those in it.
  • Know the difference between building a simple or strategic network
  • Manage visibility and reap the rewards of influential networking

If 75% of people believe their networks do NOT support the results they need, what actions can you take to beat the odds?

Julia Palmer is a respected Relational Strategist and best known for leading the face-to-face revolution!

Her expertise includes 20 years of practice and research combined with Advanced Certifications in Neuro-linguistics, Emotional Intelligence (Genos International & MSCEIT), Performance Consulting, Training and Assessment. By age 25 Julia was the General Manager of a Multi-Million-dollar global organisation, she has built her career by organising and attending thousands of networking events across all industries internationally. Now as CEO of Relatus, Julia helps you position yourself in professional networks and build your relational capabilities to maximise the human advantage.

Julia presents at functions and conferences around the world. Her clients include; 3M, ANZ, Nestle, QBE and Vodafone. She has authored three books; Relationship networks - The Future of Business', 'Schmoozing the Globe' and 'BUZZ' and appears regularly in TV, Radio and Print Media promoting the growing importance of networking relationships in business today.

Day 1
Monday, 20 June 2022
Auditorium 1

Plenary Session 1: Biomarkers of environmental exposure

Time: 9:30 - 11:30

Environmental Health and Epigenomics: New Paths to Precision Medicine

Andrea Baccarelli, MD PhD
Chair and Professor of Environmental Health Sciences
Director of the Precision Environmental Health Laborator
Columbia University Mailman School of Public Health

I will present methods and results from recent and ongoing studies using molecular biology approaches to identify individuals that are more impacted or susceptible to harmful environmental exposures. I will introduce a cadre of methods ranging from epigenome-wide DNA methylation to exosome/extracellular vesicles and epitranscriptomics as promising new paths to enhance understanding of the effects of environmental exposures on human health. Over the past few years, the application of contemporary machine learning methods to epigenomics, specifically to DNA methylation data, has shown that DNA methylation can provide accurate fingerprints of environmental factors, including tobacco smoking, environmental chemicals, and lifestyle. Those fingerprints reflect current exposure, but they also correlate well with past and cumulative exposure. Many investigators have compared the epigenome to a recording device built in our cells that captures both external and internal conditions. Using this framework provides untapped opportunities to identify the impact of risk factors at the individual level, as well as new approaches for risk stratification and personalized prevention. In this presentation, I will review current evidence from recent studies and potential contributions to human health and disease. I will discuss data sources, methodological challenges for large human studies, limitations, and possible future directions.

Biomarkers of Environmental Exposure: Arsenic and Aflatoxins

Prof Chien-Jen Chen
Genomics Research Center, Academia Sinica

Along with the rapid development in panomics, molecular biomarkers have been widely used in the environmental health studies since early 1990s. Systemic health hazards of long-term exposure to arsenic in drinking water have been intensively investigated since 1960s, especially after 1985. Significant dose-response relations have been well documented between health hazards and arsenic exposure. Biomarkers of arsenic dosimetry, early health effect, and genetic and acquired susceptibility have been developed and validated to elucidate the pathogenesis of arsenic-induced diseases. Arsenic methylation capability derived from the urinary level of various arsenic metabolites has been found to modify the health effects of arsenic. It may be regarded as the biological effective dose of arsenic exposure. Sister chromatid exchanges and DNA methylation profiles in peripheral lymphocytes or urothelial cells may be considered as the early health effects of arsenic exposure. Dietary intake of carotenoids and folate and genetic polymorphisms of xenobiotic metabolism enzymes, DNA repairment enzymes and oxidative stress-related enzymes are biomarkers of acquired and genetic susceptibility to arsenic-related health hazards. Aflatoxins are well documented to cause cirrhosis and liver cancer in humans. Monoclonal antibodies have been developed to measure the internal dose and biological effective dose of aflatoxin exposure. Urinary level of guanine-adducts of aflatoxin B1 (AFB1) has been found to be associated with the risk of hepatocellular carcinoma (HCC). Dose-response relation between serum level of AFB1-albumin adducts and HCC risk has been observed among patients affected with chronic hepatitis B or C and habitual alcohol drinkers. Genetic polymorphisms of glutathione S-transferase M1 and T1 have been found to modify the HCC risk associated with AFB1 in chronic hepatitis B patients. The dose-response relation between serum level of AFB1-albumin adducts and HCC risk was observed only in chronic hepatitis B patients with null genotype of GST M1 or T1.

Biomarkers of environmental exposure: Current status and a research gap

Shoji F. Nakayama, MD, PhD
Deputy Director
Japan Environment and Children's Study Programme Office
National Institute for Environmental Studies

Interacting with genome, environmental exposure defines our health. Christopher Wild, former Director of the International Agency for Research on Cancer, proposed a boost in research on life-long total exposure, i.e. exposome, in order to understand aetiology of diseases. In the past decades, the exposome research flourished especially in the US and EU. Exposome, in its most comprehensive interpretation, includes entire environment that we humans interact with when we live our lives. It comprises not only typical pollutants such as air pollution, chemical contaminants, lifestyle, diet, infections and physical activities but also socioeconomic status, climate, built environment, social capital and physical and psychological stress. Some of the exposome components can be quantified using biomarkers, i.e. substances measured in biological samples while the others may not have certain biomarkers. Best studied biomarkers are those of chemical exposure. Exposure to some air pollution, diet or nutrition, infectious agents and lifestyle factors, e.g. smoking, can also be assessed using specific biomarkers. No specific biomarkers have yet been found for the remaining exposome such as climate, built environment, stress and socioeconomic status. In order to interact with genome and our body system, exposome should be transformed into chemical reactions internally and thus determine our health. Finding such chemical reactions, or biomarkers of effects, is as important as investigating specific exposure biomarkers to understand comprehensive exposome. In this presentation, state-of-the-art research on exposome biomarkers will be illustrated as well as a research gap will be identified.

Plenary Session 2: Lessons learnt from cohort studies

Time: 17:00 - 19:00

Children's Environmental Health Based on Birth Cohort Studies of Taiwan

Prof Pau-Chung Chen, MD, PhD, DLSHTM
National Institute of Environmental Health Sciences
National Taiwan University College of Public Health

Environment is an important factor influencing children's health, not only at early life but also may lead to adverse consequences on later health. We conducted three birth studies in Taiwan including Taiwan Birth Cohort Study (TBCS) in 2005, Taiwan Birth Panel Study I (TBPS I) in 2004-2005, and Taiwan Birth Panel II (TBPS II) in 2009-2012. The information of general environment depended on interview questionnaires such as second-hand smoking or routine monitoring data such as air pollution in the TBCS because no biological specimen was collected. However, we collected the information of general environment by interview questionnaires as well as biological specimen such as blood, urine and others at different ages in the TBPS I & II. We measured heavy metals including Pb, Mn, Hg, As, Cd, etc by ICP-MS and cotinine, perfluoroalkyl substances, phthalates, bisphenol A and pesticides by LC-MS/MS, HPLC-MS/MS or UPLC-MS/MS. A collaboration platform of Asian birth cohort studies to promote children's environmental health is warranted. The Birth Cohort Consortium of Asia (BiCCA) was co-established in 2011 by the principal investigators of three birth cohorts in Asia including the Taiwan Birth Panel Study (TBPS), the Mothers and Children's Environmental Health Study (MOCEH), and the Hokkaido Study on Environment and Children' Health (Hokkaido Study). Up to date, BiCCA includes 33 birth cohorts with approximately 90,000 study subject that were conducted in 17 Asian countries. The BiCCA provides an information exchange platform for birth cohort in Asian countries. Targeted research collaboration is warranted and still ongoing.

Ambient Air Pollution and Health Impact in China

Prof Guang-Hui Dong
Sun Yat-sen University

Based on the large population investigations, this report systematically summarizes the effects of ambient air pollution exposure on human health in China, including the following four sections: (1) Ambient air pollution and mortality in Chinese based on the China Four Citied Study, which investigated the relationship between long-term exposure to ambient air pollution and mortality of CVDs and lung cancer in a cohort of Northern China, a total of 39,054 participants aged 40-89 years were followed from 1998-2009. (2) Ambient air pollution and morbidity in Chinese based on the 33 Communities Chinese Health Study, which compared the effects of air pollution on different circulation system diseases in 24,845 Chinese adults, ages 18-74 years old, and found that The metabolic risk factors may have exacerbated the associations of air pollutants with the prevalence of cardiovascular disease. (3) Ambient air pollution and health impact in Chinese children based on the Seven Northeast Cities (SNEC) Study, which assessed the associations between air pollution and health including respiratory system, lung function, circulation system, and mental health in 70,000 children, ages 2-14 years old, from 25 elementary schools and 50 kindergartens in the Seven Northeastern Cities during 2012-2014. (4) Toxicological Evaluation of Components in PM: It is well known that the ability of particulate matter to induce adverse health effects in human associates with not only concentration and density, but also components of ambient particles. In this section, based on clinical and experimental studies, Dr. Dong's research team systematically evaluated the effects of some components of PM2.5 including traditional components (such as F-, NH4+, Metals) and new type persistent organic pollutants (such as PFASs). These findings may help researchers, physicians, and policy makers evaluate the hazardous effects of air pollutants more completely and design targeted strategies for primary prevention of human health.

Growing Up in Singapore Towards healthy Outcomes (GUSTO) - some lessons learnt form GUSTO

Prof Johan G Eriksson, MD, DMSc
National University of Singapore (NUS)
Singapore Institute for Clinical Sciences (SICS), A*Star

The Growing Up in Singapore Towards healthy Outcomes (GUSTO) study comprises one of the most deeply phenotyped parent-offspring cohorts. In 2009 originally 1247 women were recruited and enrolled in the study, 12 years later the retention rate is around 80%. One of the primary objectives of the GUSTO study was to evaluate the role of influences operating during early development and affecting pathways to metabolic and mental health. A particular focus has been on epigenetic observations and detailed study in the first years of life, enabling examination of the potential roles of fetal, developmental and epigenetic factors in pathways towards health and disease.

Over 300 original peer-reviewed publications have been published providing detailed descriptive and cumulative data on a group of Singaporeans growing up today - findings that represent local ethnic and cultural norms. GUSTO offers opportunities to map trajectories and understand not just modifiable factors, but also relevant pathways for interventions.

The importance of the first 1000 days will be focused upon in relation to Gestational Diabetes (GDM), long-term impact of maternal mental health during pregnancy on offspring health as well as obesity with focus on primarily developmental influences.

Auditorium 1

COVID-19, environment and urban health

Time: 11:30 - 13:00

Greg Leslie - Improving resilience of public water supplies by learning from failure events in conventional drinking water systems

Prof Greg Leslie
Director of the UNSW Global Water Institute
Director of the UNESCO Centre for Membrane Science and Technology and
Professor Of Chemical Engineering, University of New South Wales

Increasing population growth, coupled with changes in the frequency and intensity of rainfall events, are forcing public water authorities to expand the practice of augmenting drinking water supplies with highly treated recycled water in a practice called potable reuse. This article presents a public health perspective on potable reuse by comparing the critical infrastructure and institutional capacity characteristics of two well-established potable reuse schemes with conventional drinking water schemes in developed nations that have experienced waterborne outbreaks. Failures in conventional drinking water systems were investigated to ascertain the cause, likelihood and consequence of system failure in 280 events over a 10 year period from the Global Infectious Disease and Epidemiology Online Network (GIDEON). The analysis indicates that drinking water outbreaks caused by microbial contamination were still frequent in developed countries and can be attributed to failures in infrastructure or institutional practices. Analysis of the documented cases showed that outbreaks often occurred due to an average combination of 3.25 causative events rather than just one particular failure mode, however, it also revealed that 17% of the cases were caused by failures in the distribution system which highlights the importance of determining the resilience of last mile infrastructure. Numerous institutional failures linked to ineffective treatment protocols, poor operational practices, and negligence were detected. In contrast, potable reuse schemes that use multiple barriers, online instrumentation, and operational measures were found to address the events that have resulted in waterborne outbreaks in conventional systems in the past decade. These results highlight desirable characteristics of potable reuse schemes from a public health perspective with potential for guiding policy on surveillance activities.

Kenichi Azuma - Factors affecting COVID-19 infection in indoor environment: exposure to SARS-CoV-2 and the transmission control

Assoc Prof Kenichi Azuma
Department of Environmental Medicine and Behavioral Science
Kindai University Faculty of Medicine
Osaka, Japan

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a new pandemic infectious disease. COVID-19 spreads primarily via respiratory droplets inhaled at short-range during close person-to-person contact (e.g., conversational distance) in a closed indoor space, especially a building. However, the significant COVID-19 clusters have occurred in indoor environment such as healthcare settings, welfare facilities, offices, restaurants, and fitness facilities. Some of those clusters suggested long-range exposure (travel farther than conversational distance) to SARS-CoV-2 by suspended aerosol (micro-droplet) transmission or indirect contact transition via shared devices might cause those clusters. In those contexts, the characteristics of environmental air quality and environmental surfaces contaminated by the virus are important factors that determine the infectivity retention and extent and speed of the spread of the virus. In addition, the relative contributions of the exposure pathways to SARS CoV-2 are important factors that determine the appropriate control of human-to-human transmission of SARS CoV-2. My colleagues and I have reviewed the factors affecting COVID-19 infection in indoor environment and studied the COVID-19 risk in indoor environment using the short-range and the long-range transmission models we developed. We have conducted the quantitative risk analysis considering multiple transmission pathways in the healthcare settings and the quantitative analysis of COVID-19 cluster in an office environment. In this presentation, the factors affecting COVID-19 infection in indoor environment, significant pathways of SARS-CoV-2 transmission in some exposure scenarios, and the effects of infection controls such as personal protective equipment or ventilation are briefly reported. Lower temperature and humidity contribute to persistence of the virus in the environment. Sunlight rapidly inactivates the virus in aerosols. Our studies suggested that preventive effects of face masks and face shields are crucial and adequate ventilation is required.

Jason Lee - Effects of heat stress on health and work productivity

Assoc Prof Jason Kai Wei Lee
Research Associate Professor
Department of Physiology and Deputy Director and Basic Science Lead
Human Potential Translational Research Programme
NUS Yong Loo Lin School of Medicine

Increasing heat stress due to climate change and urbanisation will challenge health and productivity of working people. Excessive climate conditions can also increase workplace injury rates. Heat stress is mainly dependent on environmental factors, metabolic heat production and type of clothing. The overall physiological responses from heat stress determines heat strain. Environmental determinants alone are therefore insufficient to quantify heat strain. To fully understand the impact of heat on individuals, both behavioural and physiological considerations are important. The health and wellbeing of individuals exposed to heat are linked to their thermal comfort and heat strain, encompassing intrinsic factors that should be integrated in assessing the ensuing impacts. Thermal comfort can be degraded due to passive heat stress where an individual may experience a change in skin temperature or sweat rate but often with little change in body core temperature. Heat strain, on the other hand, is often induced by extreme thermal conditions as well as exertional heat stress (due to work or exercise) that result in elevation of body core temperature. Individuals become at risk of heat strain not only when extreme heat exposure is realized, but also when they are exposed to chronic and prolonged heat exposures that increase the body's core temperature beyond what is tolerable for physiological functioning. It is therefore important to achieve a ‘human-centric’ approach, i.e. focusing on personalized characteristics of comfort, well-being, performance, and health. The “one size fits all” approach will incur productivity losses for heat-tolerant individuals while compromising heat-intolerant workers.

ISES Symposium: Health hazards of air pollutants and their toxicological mechanisms

Time: 13:30 - 15:00

Air pollution is a major threat to health, climate change and sustainable economic development, and is a major environmental risk affecting health. Air pollution ranks fifth in the global burden of disease. According to the global burden of disease, the number of deaths caused by PM2.5 alone increased from 3.5 million in 1990 to 4.2 million in 2015, a 20% increase. About 3 million people die each year from outdoor air pollution. Indoor air pollution can also be deadly. In 2012, an estimated 6.5 million deaths (11.6% of all world deaths) were associated with indoor and outdoor air pollution. Nearly 90 percent of air pollution-related deaths occurred in low- and middle-income countries, and nearly two-thirds occurred in the WHO South-East Asia Region and Western Pacific Region. Air pollution also increases the risk of severe acute respiratory infections. The problem of air pollution has become a major obstacle to human health and economic development. In recent years, the research on air pollution has increased year by year, and the study on the toxicity mechanism of air pollution has been gradually deepened. Therefore, this workshop is conducted to facilitate the discussion on the latest progress of current air pollution and health effects and toxicity mechanism, further inspire the research ideas in this field, and facilitate further innovation./p>

Jicheng Gong - The implication and contribution of personal exposure studies to the causal relationship between air pollution and human health

Jicheng Gong
Peking University

Exposure to air pollutants has been associated with the incidence and mortality of metabolic syndrome, but the underlying molecular mechanisms remain inadequately understood. Altered amino acid metabolism is postulated to play a role in the development of metabolic syndrome. To explore perturbation in amino acid metabolism in association with personal air pollution exposure, we examined molecular-level amino acid metabolism responses to personal air pollutant exposure. We found some evidence that air pollution (including O3, PM2.5, NO2, and SO2) may induce acute perturbation in amino acid metabolism; short-term low-level O3 exposure could be associated with alternation of urea cycle activity among healthy adults; O3 metabolic derangement is likely mediated by the neuronal stress response pathway.

Bin Zou - Efforts in reducing air pollution exposure risk in China: State versus individuals

Bin Zou
Central South University

China has made great efforts towards air pollutant concentration control during the past five years, which has led to positive outcomes. However, air pollutant concentration focused efforts were considered separately from human exposure risk. And this might result in a misunderstanding that reducing exposure risk can only rely on the national level measures of air pollutant control. This study integrates the first Chinese survey of human activity patterns and the spatially continuous high-resolution PM2.5 concentration maps from 2013 to 2017. The effects on risk reduction from multi-scale and multi-object perspectives are deeply investigated. Results show that the reductions of PM2.5 concentration and associated reductions of exposure risk from 2013 to 2017 were 40% and 35.7%, respectively. They also showed that both the reduction of PM2.5 concentrations and change of personal behavior patterns were effective for risk reduction when China’s total PM2.5 exposure risk was higher than 1.58. However, only individual behavior changes contributed to risk reduction for scenarios with state-level risk value below 1.58. For regional strategies, threshold values for PM2.5 exposure risk control differentiating national measures or personal efforts were spatially and temporally dependent. The role of personal behavior changes on PM2.5 exposure risk reduction was growing in these five years with concentration rapidly decreasing regions. The findings suggest that people-centered air pollution exposure risk prevention not only depends on government management for air pollution control, but also on individual changes of activity patterns. Efforts from the state and individuals are both essential for reducing air pollution exposure risk in China, especially growing individual efforts are needed in regions with the decreasing air pollutant concentrations in the coming future. Moreover, this study mainly discussed the PM2.5 exposure risk from the macroscopic perspective, the research at the microcosmic perspective is also needed in the further study.

Qian Guo - Interaction between PM2.5 and physical activity on adulthood obesity: Observations from a Chinese nationwide representative sample

Qian Guo
University of Science and Technology Beijing

Long-term exposure to PM2.5 has been associated with increased obesity risk, while physical activity (PA) is a suggested protective factor. This raises a dilemma whether the increased dose of PM2.5 due to PA-intensified ventilation would offset the benefits of PA. Using a national representative sample, we aim to (1) ascertain inclusive findings of the association between PA and obesity, and (2) examine whether PM2.5 exposure modifies the PA-obesity relationship. We recruited 91,121 Chinese adults from 31 provinces using a multi-stage stratified-clustering random sampling method. PM2.5 was estimated using a validated machine learning method with a spatial resolution of 0.1° x 0.1°. PA intensity was calculated as metabolic equivalent (MET)-hour/week by summing all activities. Body weight, height, and waist circumference (WC) were measured after overnight fasting. Obesity-related traits included continuous outcomes (Body mass index [BMI], WC, and waist-to-height ratio (WHtR)) and binomial outcomes (general obesity, abdominal obesity, and WHtR obesity). Generalized linear regression models were used to estimate the interaction effects between PM2.5 and PA on obesity, controlling for covariates. The results indicated that each IQR increase in PA was associated with 0.078 (95% CI: -0.096 to -0.061) kg/m2, 0.342 (-0.389 to -0.294) cm, and 0.0022 (-0.0025 to -0.0019) decrease in BMI, WC, and WHtR, respectively. The joint association showed that benefits of PA on obesity were attenuated as PM2.5 increased. Risk of abdominal obesity decreased 11.3% (OR=0.887, 95% CI: 0.866, 0.908) per IQR increase in PA among the low-PM2.5 (≤55.9 µg/m3) exposure group, but only 5.5% (OR=0.945, 95% CI: 0.930, 0.960) among the high-PM2.5 (>55.9 µg/m3) exposure group. We concluded the increase in PA intensity was significantly associated with lower risk of obesity in adults living across mainland China. Reducing PM2.5 exposure would enhance the PA benefits as a risk reduction strategy.

BiCCA Cohort Symposium: Next steps research of Asian birth cohort

Time: 15:00 - 16:30

Birth cohort studies are an ideal design to explore the impact of prenatal and early postnatal exposures/factors on child health and disease, not only early in life but also potentially leading to adverse outcomes later in life. Therefore, Birth Cohort Consortium of Asia (BiCCA) was established to facilitate exchange of knowledge and collaboration between cohorts and researchers, and exploration of future need for children's environmental health research. Currently, BiCCA consists of 34 cohorts with a total of over 80,000 children in 17 countries: Australia (1 cohorts), Bangladesh (1), Canada (1), China (5), Iran (1), Japan (5), Korea (5), Malaysia (1), Mongolia (2), Nepal (1), Philippine (1), Singapore (1), Sri Lanka (1), Taiwan (3), Thailand (1), United Arab Emirates (1), and Vietnam (3). Most of these birth cohorts were small to medium-sized, with fewer than 1000 participants, and only a few studies included more than 5000 participants. Challenges were different such as follow-up protocols, verifiable hypothesis, statistical power and cost.

In this symposium, we would like to provide a prospective view on the next steps for Asian birth cohort studies in different aspects such as sample size, enrollment starting point, collaboration, and utilization of health insurance systems. First, follow-up protocol focusing on heavy metal exposures on neurodevelopment will be reported by Birth Cohort Study in Nepal, which enrolled only 100 mother-infant pair. The second is the introduction of preconception and pregnancy cohort in Shanghai. Couple-based approaches have been employed to examine the relationship between exposure to multiple pollutants and time-to-pregnancy and reproductive health. Next, conceptual framework for collaboration among five birth cohorts in Taiwan will be reported. This family based study plans to recruit approximately 5000 subjects in 1250 families from an initial 5000 mother infant pairs recruited between 2000 and 2014. Individual questionnaires and biomarkers as well as information linked to National Health Insurance Dataset will be used to investigate the impact of the environmental and genetic factors on long-term incidence of allergic disease, neurobehavioral development, and metabolic abnormalities. The final presentation will be the nationwide long-term birth cohort study launched in Korea in 2015. The Korean CHildren's ENvironmental health Study (Ko-CHENS) has recruited a total of 71,260 pregnant women, including 5,083 pregnant women in the Core Cohort and aim to address various environmental health issues and establish a sustainable environmental health policy and management system in Korea.

Through the above themes, the challenge of different designed birth cohort studies will be presented. International collaboration should be accelerated in the future through experiences sharing and information exchange to improve child environmental health.

Rajendra Parajuli - Neurodevelopment, Heavy Metal, IQ, Nepal, Birth Cohort Study, Follow Up, Modeling, HOME Environment

Assoc Prof Rajendra Prasad Parajuli
Central Department of Zoology, Tribhuvan University

Enormous efforts have been devoted to clarify determinants of neurodevelopment of humans. During the prenatal period, exposure of fetuses to heavy metals [lead (Pb), arsenic (As) were reported to be associated with prenatal and postnatal neurodevelopment. Maternal psychological conditions and in utero growth environments also affected the neurodevelopment during the prenatal and postnatal periods. During the postnatal period, growth environments (e.g., nutritional status, maltreatment, child abuse, neglect, gastrointestinal helminths) are the prominent determinants of neurodevelopment. Numbers of studies have evaluated the effect of perinatal exposure of Pb and As on later neurodevelopment, but most of the studies evaluate such effect in developed countries. The dose-response relationship and time lag effect remain inconclusive for lead. A limited number of studies evaluated the effect of pre and postnatal As, on neurodevelopment in humans and the persistency of such effect on later neurodevelopment (adolescence) remains inconclusive.

The objectives of the present study are
(1) to evaluate the postnatal exposure to heavy metals (Pb, As), and postnatal growth environments (nutritional status, maltreatment, child abuse, neglect, gastrointestinal helminths
(2) to evaluate Wechsler Adult Intelligence Scale-Third Edition (WISC III) intelligent Quotient (WISC IQ) score of birth cohort adolescence and
(3) to investigate the association between in utero as well as postnatal Pb As, postnatal growth environment, and IQ score.

The existing "Birth Cohort Study in Chitwan Valley, Nepal" (Parajuli et al, 2013; 2014 and 2015) will be followed up at 14 years visiting their home by the same research team using existing contact information via prior appointment.

Jun Jim Zhang - Preconception exposure to per- and polyfluoroalkyl substances (PFAS) and couple fecundability

Prof Jun Zhang
Shanghai Jiao Tong University

The Shanghai Birth Cohort study is composed of a preconception cohort and a pregnancy cohort. We recruited 1180 couples who came to two preconception care clinics for care in Shanghai from 2013 to 2015. Couples were approached by trained research assistants in the waiting rooms.

They were eligible if:
(i) they were 20 years of age or older;
(ii) at least one of the couple was a registered Shanghai resident;
(iii) they planned to be pregnant recently;
(iv) neither of the couple had been diagnosed as having fertility problems;
(v) once pregnant, they planned to seek prenatal care and give birth at the SBC participating hospitals;
(vi) the family intended to stay in the catchment area for at least 2 years; and
(vii) they were willing to sign a consent form and be followed for at least 2 years.

Couples who had tried to conceive spontaneously for more than 12 months and were still not pregnant, or sought reproductive assistance, were not enrolled in this cohort. Detailed information on sociodemographic characteristics, health behavior, mental health, physical activities, family, medical, and reproductive history, environmental exposure and food frequency was collected at the enrollment. Blood, urine and semen samples were collected. In the past several years, we focused on PFAS, phenols and organophosphate pesticides exposure, and have examined the sources of the exposure and their associations with male and female reproductive outcomes. We found that PFAS may affect male reproductive hormone levels and semen quality. PFAS, organophosphate pesticides, and triclosan were associated with abnormal menstruation. BPA and triclosan were associated with reduced fecundability, and organophosphate pesticides with prolonged time-to-pregnancy. A couple-based approach was also taken to examine the association of the exposure of these pollutants with time-to-pregnancy. A preconception cohort is a useful way to address the environmental concerns on reproductive health.

Hui-Ju Wen - Conceptual framework of birth cohort based family study in Taiwan

Hui-Ju Wen
National Institute of Environmental Health Sciences, National Health Research Institutes

Children's health status is crucial because their growth, physical and mental development may also affect their health in adulthood. Therefore, investigations of the early-life factors associated with children's health and development are beneficial for health promotion, disease prevention, and reduction of medical expenditures.

We proposed to combine five major birth cohorts established in 2000~2014 consisting of over 5000 maternal and infant pairs with blood biomarkers and follow-up data. We planned to follow the cohort with the invitation of the child subject's mother, father, and one sibling. This study is expected to track 1,250 families, and thereby a total of around 5,000 subjects will be recruited. We shall utilize data on the subjects' National Health Insurance and individual questionnaires and biomarkers. In addition, we shall investigate the environmental and genetic factors on the effects for long-term incidence of allergic disease, neurobehavioral development, and metabolic abnormalities. The mechanism of these disease pathogenesis will be carried out via collaborations with basic scientists.

The resulting association of multiple environmental and genetic factors with important health and disease may help achieve the health benefits of early prevention and disease intervention.

Eunhee Ha - Progress and Future Plans on the Korean CHildren's ENvironmental health Study (Ko-CHENS) Birth Cohort

Prof Eunhee Ha
Dept. Environmental Medicine, Ewha Womans University College of Medicine

The Korean CHildren's ENvironmental health Study (Ko-CHENS) is a nationwide longterm birth cohort study in Korea launched in 2015. The Ko-CHENS is designed to evaluate the association between environmental exposures and health effects in children from conception until adulthood. The Ko-CHENS aims to provide guidelines that apply a life-course approach to the environmental health management system.

The Ko-CHENS plans to recruit a total of 70,000 expectant mothers through its two enrollment tracks:
1) 65,000 in the Main Cohort and
2) 5,000 in the Core Cohort.

Pregnant women and children recruited in Core Cohort will have a regular follow-up for developmental and laboratory tests for the next 20 years. The pregnant women and children in Core Cohort will be tracked through data linkage with relevant authorities. Until now, Ko-CHENS has recruited a total of 71,260 pregnant women including 5,083 pregnant women in the Core Cohort. In Core Cohort we found 5.4% preterm births, 4.8% low birth weight, and 2.9% macrosomia newborns. Prenatal mercury exposure was 3.19㎍/L, while lead and mercury were 0.46㎍/dL and 0.22㎍/L, respectively. Methylparaben exposure in 2-year-old children was 129.44 which was higher than their US counterparts.

The Ko-CHENS pursues:
1) to expand environmental health research through specialized research developments;
2) to develop customized national environmental health management system based on precautionary principles; and
3) to establish a network of Korean Pediatric Environmental Health Specialty Units.

Thus, Ko-CHENS plans to address various environmental health issues and render a sustainable environmental health policy and management system in Korea.

Auditorium 2

Waste in Asia, its health risks and management

Time: 11:30 - 13:00

Asia is the most rapidly industrializing and growing region in the world. More than a half population of the globe lives in the Asia region. There are disparities in economic conditions as well from highly developed to rapidly developing countries. Waste is a topic for all countries. Along with growing population, volumes of waste amount also increasing, due to the rapid production and consumption. Waste composition becomes more and more complex due to new materials. Lifetime of the product becomes shorter due to replacing by new product. Our globe is being invaded with single use product and packages. Waste consists hazardous chemicals, hazardous materials, and hazardous pathogen. Waste is a key issue for environmental sustainability, as well for human health.

This symposium consists of three presentations from three different countries with different waste in Asia. The first topic is about the medical waste management in Bangladesh. The COVID-19 pandemic forces people to be vaccinated, at the same time fragile medical waste management system in Bangladesh was revealed. The study focused on a nation-wide legitimate COVID-19 vaccination waste estimation, strength, weakness, opportunity and threat analysis, and drivers, pressure, state, impact and response framework analysis to identify the present state of medical waste management. A huge waste load would be added to the existing medical waste stream which need much more attention that ensure the safe management of this waste.

The second topic is about electronic waste (e-waste). E-waste, has emerged globally as a fast-growing solid waste of significant environmental health concern. In Vietnam, e-waste has become an issue of public health and environmental concerns due to the impact of its discarding and improper recycling. This presentation provides comprehensive information on the current status of environmental pollution of hazardous substances derived from informal e-waste processing, characterizing the potential environmental health risks, and provide valuable references for further e-waste management strategy and relevant interventions.

The third topic is about air pollutants from municipal solid waste incinerator (MSWI) in Thailand. The waste incinerators have been used recently to reduce municipal waste and to produce electricity as a by-product using the waste-to-energy (WtE) concept. However, they also create health risks to the people living nearby because of the pollutants emitted from municipal solid-waste incinerators. Ground-level concentrations of air pollutants emitted from MSWI were estimated using an air quality model; AERMOD. Also, the health risk assessment (HRA) was conducted as one of the recommended tools for estimating adverse health effects on people living near municipal solid-waste incinerators.

Last, but not least, the topic is about the usage of aqueous film-forming foam (AFFF) in the US military base and the Self-Defense Force base of Japan. Although it is not exactly “waste”, once these perfluorooctane sulfonic acid (PFOS) containing AFFF used, it is highly possible that the PFOS contamination remains in the site. Residents of Ginowan City near Futenma base had average blood concentration of PFOS at higher levels than those of other sites, possibly due to drinking water contaminated with PFOS by historical use of AFFF.

Hien Thi Thu Ngo - E-waste burden in Vietnam: A short review

Dr Hien Thi Thu Ngo
Thang Long University

Electronic waste, coined e-waste, has emerged globally as a fast-growing solid waste of significant environmental health concern. Improper e-waste disposal or recycling has resulted in environmental contaminations negatively impacting on ecosystem and causing health risks from hazardous exposures. In Vietnam, e-waste has become an issue of public health and environmental concerns due to the impact of its discarding and improper recycling.

The main objectives of this review are to
1) provide comprehensive information on the current status of environmental pollution of hazadous substances derived from informal e-waste processing in Vietnam
2) characterizing the potential environmental health risks of exposure to toxic substances via different environmental media and pathways; and
3) provide valuable references for father environmentally sound e-waste management strategy and relevant interventions for better human health of exposure to e-waste.

Many cross-sectional studies have investigated the current environmental pollution of contaminants such as persistent organic pollutants (POPs) including polybrominated diphenyl ethers (PBDEs), brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), halogenated flame retardants (HFRs), dioxin-related compounds (DRCs), and heavy metals derived from informal e-waste processing area in Vietnam. Exposing to multiple toxic substances via different environmental media and pathways may cause aggregative health risks to humans, particularly high concentrations of blood heavy metals, DNA damage, carcinogenic and non-carcinogenic risks found in exposed children; high levels of POPs found in blood, urine, breast milk, and hair among e-waste recyclers. Until now, there has not been any complete e-waste recycling technology and sustainable management system applied in Vietnam. Processing e-waste had not been specifically regulated by Vietnamese government. This brief review accentuated the importance of mitigation methods of hazardous substances released from informal e-waste processing facilities to prevent their potential environmental health risks to human health.

Patsiri Srivieng - Air dispersion modeling and health risk assessment of air pollutants from a municipal solid waste incinerator development projects in Thailand

Dr Patsiri Srivieng
Thammasat University

One of the recommended tools for estimating adverse health effects on people living near municipal solid-waste incinerators (MSWIs) is the health risk assessment (HRA). In this study, the emissions from MSWI stacks were estimated using the existing MSWI. Ground-level concentrations of air pollutants emitted from MSWI were estimated using an air quality model AERMOD.

Air pollutants include
1) The criteria air pollutants (CAPs) of sulfur dioxide, carbon monoxide, total suspended particulate, oxide of nitrogen and lead;
2) hazardous air pollutants (HAPs) such as arsenic, cadmium, chromium, mercury, nickel, and tetra- through octa- chlorinated dibenzo-p-dioxin/chlorinated dibenzofurans (CDD/CDF); and
3) hydrogen chloride. Five study areas were selected as representative of the factors of size and location, namely, Phra Nakhon Si Ayutthaya, Khon Kaen, Lamphun, Rayong, and Surat Thani. For HAPs, the estimated carcinogenic risks were compared with the reference significant level of 10-6 as suggested by the U.S. EPA, while for non-carcinogenic risks, the acceptable value should be lower than 1.

The scenario that the receptors exposed the pollutants since they were born. Result show that the multi-chemical cancer risk (CR) for the various sizes and locations of MSWIs are higher than the reference significant risk level (10-6) in the large size of MSWIs. Chromium was the most concerned chemicals as its cancer risk values were mostly not significant. The hazard index (HI) is within the U.S EPA acceptable limit. Cadmium and CDD was found to be the most approaching to the reference level. With these results, the proposed MSWIs should have the appropriate air pollution controls and monitoring measure, especially for those emitting carcinogenic pollutants. Moreover, the cancer incidence surveillance system should be designed to monitor the long-term health impact of the proposed MSWIs.

Air pollution and health

Time: 13:30 - 15:00

Ho Kim - Health effects of air pollution and heat modified by urbanization in the Asian countries

Prof Ho Kim
Seoul National University

Despite the fact that urbanization is frequently discussed in climate change and air pollution studies, the multifaceted impact of urbanization on heat and air pollution vulnerabilities in urban and rural areas has received little attention. We aim to present the unequal effects of urbanization on heat and air pollution vulnerabilities in urban and rural locations in the East Asian countries.

In addition to the climate change and air pollution issues that our generation faces, I will discuss the effects of rapid urbanization and population aging in East Asia on health issues, as well as the challenges that modern epidemiologists face when dealing with complex public health issues, taking into account the Covid-19 situation and international collaboration.

We have observed that population concentration has increased in metropolitan areas, with the highest risk of heat-related death in prefectures with the most people in Japan. Higher heat-mortality risk was linked to higher population density and apartment percentages, as well as lower forest area and medical services; these links have gotten stronger since the 2000s. But we also found literatures reporting higher heat risks in the rural areas rather than urban in China. Our previous studies showed higher heat risks in the extreme urban as well as rural areas in South Korea.

Our data reveal that the association between population density and heat- and air-pollution-related mortality differs between urban and rural areas, and that district characteristics linked to these environmental risks alter the heat and air-pollution effects. These findings can assist policymakers in better understanding the complex impact of urbanization on environmental health concerns, as well as provide scientific support for resource allocation decisions.

Kayo Ueda - Addressing the health risks of air pollution from vegetation fires in Southeast Asian region

Prof Kayo Ueda
Graduate School of Medicine, Hokkaido University

Smoke emitted from vegetation fires contains various hazardous air pollutants, such as particulate matter (PM10, PM2.5), polycyclic aromatic hydrocarbons (PAHs), and other gaseous pollutant, which are known to pose significant health effects. Epidemiological studies have clarified and quantified the association between various health outcomes and air pollutants from vegetation fires. They can be utilized to evaluate the effectiveness of policies on fire controls as well as to implement health impact assessment (HIA) of fire mitigation policies. In this presentation, I will discuss how epidemiological approaches can be utilized to mitigate air pollution-related health consequences from vegetation fires.

In our scoping review, over 35 epidemiological studies were published, most of which focused on the health effects of short-term exposure of smoke haze, from Indonesia, Malaysia, Brunei, Singapore, and Thailand. Frequently used exposure indicators included PM10 and Pollutant Standard Index (PSI). Two studies from Malaysia and Thailand were highlighted to provide an insight into exposure assessment of smoke-related air pollutants.

Epidemiological evidence of air pollutants, such as PM2.5 and ozone, has been used for HIA, in which the potential health effects of air pollution by a given intervention. In the experience of an HIA conducted in Thailand, disability-adjusted life year (DALY) of PM2.5 emitted from different rice straw utilization which are alternative to open burning was estimated. Risk function for fire-related PM was not available, and that derived from the epidemiological studies for urban air pollution was used instead.

To move mitigation forward, it is necessary to accumulate the epidemiological evidence, emphasize on long-term health effects, refine exposure assessment, and evaluate the effectiveness of fire control interventions.

Masahiro Hashizume - Climate change and human health

Prof Masahiro Hashizume
The University of Tokyo

Growing evidence suggests that changes in temperature and precipitation associated with climate change will adversely affect human health. In its Sixth Assessment Report, the Intergovernmental Panel on Climate Change reports that the population exposed to heatwaves will continue to increase globally due to further warming, leading to large geographic variations in heat-related mortality unless extra adaptation measures are taken. The risk of climate-sensitive foodborne, waterborne, and vector-borne infectious diseases is projected to increase under all levels of warming unless additional adaptation measures are taken. Under further warming, increased mental health problems are also projected. Low-income countries will be most adversely affected by the health impacts arising from these increased risks. The urban poor, elderly, children, traditional communities, subsistence farmers, and coastal residents will be most at risk.

Further efforts to improve our understanding of how adaptation measures can effectively reduce adverse health impacts are essential. In addition, a better understanding of the health co-benefits of climate change mitigation policies would facilitate the establishment of appropriate mitigation policies and public health activities that support sustainable development for all.

Sagnik Dey - Health impacts of air pollution in India: Policy Implications

Sagnik Dey
Indian Institute of Technology Delhi

Air pollution exposure in India is among the highest in the world. However, health impact of air pollution is not an integral part of air quality management policy in India. Clean air targets are set but a robust framework to assess health benefits form various interventions is lacking. The Global Burden of Disease (GBD) study addressed this gap, but there is still an apprehension about the GBD results in policy making. This has called for indigenous evidence using health data from India. In this work, I will present recent studies conducted using exposure and health data from India, and how such studies are big integrated into the policy framework.

Oral abstract presentation: Air pollution and health

Time: 15:00 - 16:30

Joshua Jones - Long-term exposure to low-concentration PM2.5 and heart disease in older adult men in Perth, Australia: the Health in Men study

Mr Joshua Jones
University of Western Australia

To identify and characterise the relationship between long-term ambient PM2.5 exposure and ischaemic heart disease (IHD), heart failure (HF) and atrial fibrillation (AF) in older adult males living in a city with low PM2.5 concentrations.

The study population was males over 65 years of age who were enrolled in the Health in Men study from 1996 to 1999 and resided in the Perth Metropolitan area. Land use regression models were used to estimate each participant's PM2.5 exposure. Incident heart disease outcomes were identified via the Western Australia Data Linkage System. Hospitalisation data were available until 29 June 2019 and death data until 21 December 2017. Cox-proportional hazards models were used to analyse the relationship between PM2.5 exposure, modelled with a restricted cubic spline, and the four study outcomes: IHD death or hospitalisation, HF hospitalisation, hospitalisation with a principal diagnosis of AF, and, hospitalisation with a principal or additional diagnosis of AF. Models were adjusted for confounding demographic and lifestyle factors.

After excluding participants with pre-existing disease at baseline, 8328 men were included in the IHD model, 11,148 in the HF model, and 10,864 in the AF models. During follow-up there were 2356 (28.3%) IHD hospitalisations or deaths, 1642 (14.7%) HF hospitalisations, 1048 (9.6%) hospitalisations with a principal diagnosis of AF, and 3440 (31.7%) hospitalisations with a principal or additional diagnosis of AF. In the adjusted models higher PM2.5 concentrations were associated with increased incidence of IHD, HF and AF above a threshold concentration of 6μg/m3. The hazard ratio for IHD hospitalisation or death at a mean PM2.5 concentration of 7μg/m3 compared to 1μg/m3 was 1.43 (95% confidence interval 1.22-1.68).

Higher concentrations of long-term ambient PM2.5 were associated with increased incidence of IHD, HF and AF in older adult males, above a threshold concentration of 6μg/m3.

Pei-Yi Wong - Effects of heavy metal constitutes of PM2.5 on dementia in an industrialized city based on a spatial mixed prediction model approach for exposure assessment

Ms Pei-Yi Wong
National Cheng Kung University

Introduction: Previous studies evidence that air pollution increases the incidence risk of dementia or cognitive decline, especially in the elderly. However, there are limited evidence demonstrate the association between heavy metal constitutes of PM2.5 exposures and the incidence rates of dementia. This study aims to investigate the effects of exposure to heavy metals constitutes of PM2.5 including lead (Pb), manganese (Mn), vanadium (V) on incidence rates of dementia in an industrialized area.

Method: The township-level of age above 50 years old incidence rates of dementia of 2014 and 2015 were extracted form National Health Insurance Research Database (NHIRD). Exposure data of heavy metals with monthly and 50-m resolution including Pb, Mn, and V was estimated using land-use regression coupled with XGBoost machine learning algorithm based on on-site measurements. This study controlled for several potential covariates to adjust models including urbanization level, education level, income tax, time, centroid of each township, prevalence rate of diabetes, hypertension, and hyperlipidemia. A generalized additive mixed model (GAMM) was applied to investigate the association between 3-month, 2-month, and 1-month moving average of Pb, Mn, and V exposures and the incidence rates of dementia, using single-, bi-, and tri- pollutant models.

Results: The performance (R2) of spatial mixed prediction models in estimating Pb, Mn, and V was 0.78, 0.81, and 0.56, respectively. An interquartile increase of 3-month, 2-month, and 1-month moving average of Pb, Mn, and V exposures was positively associated (p < 0.05) with dementia incidence. The estimated risk ratio was higher in 3-month moving average exposure, followed by 2-month and 1-month exposures.

Conclusion: Exposure to heavy metal constitutes of (Pb, Mn, and V) of PM2.5 may contribute risk to incidence of dementia. Our findings recommend policymakers and communities support the benefit of eliminating industrial heavy metal emission in lowering the risk of dementia incidence.

Wei Wu - Semen quality and sperm DNA methylation in relation to long-term exposure to air pollution in fertile men: a cross-sectional study

Prof Wei Wu
Nanjing Medical University

Some studies have examined the association between air pollution and semen quality. While it is less of evidence on the sperm quality after long-term air pollution exposure, especially the co-exposure of different air pollution components. Additionally, the role of DNA methylation in it hasn't been confirmed. This study aimed to investigate whether long-term exposure to air pollution was associated with semen quality, as well as to explore the effect of sperm DNA methylation in such association. From 2014 - 2016, 1,607 fertile men were enrolled to evaluate 14 parameters of semen quality. Exposure window was defined as one-year before semen sampling. Multivariable linear regression and weighted quantile sum (WQS) regression model were used to investigate the association between six air pollutants co-exposure and semen quality. Sensitivity analysis regarding at the normal semen quality group was also conducted. Semen samples were randomly selected from 200 participants to detect the genomic 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5-hmC) levels in sperm. In the total population, PM10, PM2.5, SO2, and NO2 were negatively associated with sperm total motility (PM10: β = -2.67, P = 0.009; PM2.5: β = -2.86, P = 0.004; SO2: β = -2.32, P = 0.011; NO2: β = -2.21, P = 0.012). Results of the normal semen quality group were consistent with those from the whole population. WQS regression results indicated significant decreasing sperm total motility after the co-exposure of the six air pollutants (β = -1.64, P = 0.003) in whole participants. Wherein, PM10 accounted for largest proportion (43.4%). The 5-hmC level was positively associated with PM10 exposure (β = 0.002, P < 0.001). Long-term exposure to PM10, PM2.5, SO2, and NO2, as well as co-exposure to six air pollutants, reduced semen quality in fertile men. As the most significant contributor of air pollutant, PM10 exposure decreased sperm DNA methylation.

Cheng Li - Effects of particulate matters on the risk of gestational hypertensive disorders among women with natural conception and assisted reproductive technologies

Dr Cheng Li
Obstetrics and Gynecology Hospital
Institute of Reproduction and Development
Fudan University

Objective: Associations between particulate matter (PM) and gestational hypertensive disorders (GHD) are well documented, but there is no evidence on the associations between PM and GHD progression, especially among pregnant women with assisted reproductive technology (ART) conceptions. This study aimed to explore the effects of PM on the incidence and progression of GHD among pregnant women with natural or ART conception.

Methods: The study enrolled 185,140 pregnant women who delivered between 2014 and 2020 in two hospitals. The effects of PM2.5 and PM10 at each period on the occurrence of GHD (including gestational hypertension (GH), preeclampsia, and preeclampsia with severe feature) and GHD with progression were estimated using a generalized linear model. Stratified analysis was also conducted according to the natural conception and ARTs.

Results: The fitted spline curves for gestational hypertension (GH), preeclampsia and progression with GHD were similar to the temporal trends of PM2.5 and PM10. During the 3 months preconception, 10-μg/m3 increases in PM2.5 and PM10 concentrations were associated with increased risks of GH (PM2.5: aOR=1.033, 95%CI: 1.015-1.051; PM10: aOR=1.020, 95%CI: 1.005-1.036) and preeclampsia (PM2.5: aOR=1.024, 95%CI: 1.001-1.048; PM10: aOR=1.023, 95%CI: 1.004-1.041) among pregnant women with natural conception. Furthermore, among women with ART conceptions who suffered current GHD, 10-μg/m3 increases in PM2.5 and PM10 concentrations in the third trimester elevated the risk of progression (PM2.5: aOR=1.090, 95%CI: 1.015-1.171; PM10: aOR=1.077, 95%CI: 1.008-1.150).

Conclusions: PM2.5 and PM10 exposure revealed different risk profiles for GHD and its progression among pregnant women with natural or ART conceptions. Pregnant women with natural conception should avoid PM exposure during preconception and early pregnancy to protect themselves from GH and preeclampsia. For pregnant women with ART conceptions suffered from GHD, it is necessary to avoid PM exposure in the third trimester to prevent the disease from progressing.

Auditorium 3

Oral abstract presentation: Environmental pollutants and health

Time: 11:30 - 13:00

Jieying Lin - Mechanistic, Bottom-Up Physiologically-Based Toxicokinetic Modelling to Predict the Transporter-Dependent Disposition of Perfluorooctanoic Acid

Ms Jieying Lin
A*STAR Skin Research Labs

Notoriously known as a forever chemical, perfluorooctanoic acid (PFOA) is an industrial compound that is highly persistent in both the environment and human body, with an extremely long half-life of 2.7 years. Exposed to humans through various sources including contaminated food and water, and consumer products such as food packaging and non-stick cookware, PFOA is detected in 95% of blood samples. The bioaccumulation of PFOA is associated with adverse effects including cancer, thyroid hormone disruption and developmental toxicity. Presently, a limited understanding of PFOA toxicokinetics hampers the assessment of its safety. Metabolically inert, transporters drive the disposition of PFOA in the human body. Herein, we aimed to utilize bottom-up physiologically-based toxicokinetic (PBTK) modelling to predict the transporter-dependent disposition of PFOA and rationalize the mechanisms underpinning its long half-life. In vitro uptake assays were conducted for transporters found in the liver and kidney to obtain kinetic parameters incorporated into the model, along with quantitative proteomics-based mechanistic in vitro-to-in vivo extrapolation (IVIVE). Our model accurately predicted the clinical TK profile of PFOA and demonstrates the role of poor renal clearance in the long half-life of PFOA. Importantly, our model permitted the inference of an undiscovered transporter that was necessary to recapitulate the long half-life of PFOA observed at low exposures in biomonitoring studies. Hence for the first time, we were able to reconcile the vastly different PFOA half-lives estimated from clinical and biomonitoring studies. We next intend to deploy our model to investigate toxicities in other vulnerable populations and determine safe exposure limits. PBTK modelling is a powerful and useful tool to predict the human toxicokinetics of hazardous chemicals without performing animal or human studies.

Nan Lin - Volatile Organic Compounds in Disposable Diapers and Baby Wipes in the US: A Survey of Products and Health Risks

Dr Nan Lin
Shanghai Jiao Tong University

Diapers are worn by young children and the elderly, and both of these groups can have thin and sensitive skin that is highly vulnerable to chemical exposures. Diapers contain a number of volatile organic compounds (VOCs) used as specific ingredients and as inadvertent or residual components. The identification and quantification of these VOCs, and their potential health risks, have not been reported previously. In this exploratory study, 31 commercially available disposable hygiene products in the US were collected and analyzed for 98 target VOCs. Exposures and risks were modeled using reasonable upper level exposure scenarios. Adult diapers contained the highest total target VOC concentration (median level of 23.5 µg/g), and the predominant VOCs were mostly alkanes; the non-cancer risk from these VOCs, expressed as a hazard ratio, was sometimes very large (maximum of 1609). Baby diapers contained several known or suspected carcinogens, including benzene and 1,4-dioxane, and the corresponding lifetime cancer risk approached 1 in a million, a common reference level. Typically, store-brand products had higher concentrations of specific VOCs than generic brands. Products labeled as “organic,” or “for sensitive skin” did not necessarily have lower VOCs concentrations. Our results suggest that all of these disposable items contained some toxic VOCs, and tests show instances where VOC levels are high enough to cause risks that should be addressed. We recommend that toxic ingredients in these products should be eliminated, that all chemicals ingredients should be disclosed, and that follow-up monitoring be used to verify the safety of these products.

Zulkhairul Naim Bin Sidek Ahmad - Determinant of knowledge and practice of pesticide use among farmers in Kelantan, Malaysia

Dr Zulkhairul Naim Bin Sidek Ahmad
Department Public Health Medicine
Faculty of Medicine and Health Sciences
Universiti Malaysia Sabah

Introduction: Adequate knowledge is a powerful tool to promote more positive attitudes and safe working practices. There is little information available on knowledge and practice of pesticide use in Malaysia. Therefore, this study was conducted to determine the associations between knowledge and practice of pesticide use and associated factors among farmers.

Methods: A cross-sectional study was carried out in farming communities in Bachok and Kota Bharu District, Malaysia during September 2019 to January 2020. Farmers who had sprayed were interviewed and information was obtained on demographics, working practices and knowledge and practice of pesticide use. Binary logistic regression was used to determine the association between the knowledge and practice of pesticide use and associated factors.

Results: 150 farmers growing either rice (n=83) or vegetables/fruits (n=67) participated in this study. The median (Q1-Q3) level of knowledge and practice among farmers was 10.0 (8.0-10.0) and 52.0 (50.0-55.0), respectively. The correlation revealed a weak significant positive linear correlation between knowledge and practice score (p<0.01).

Adjusting for age, not using PPE, being exposed as a bystander and repairing equipment after pesticide use was associated with poor knowledge with OR (95% CI) being 5.2 (1.5, 18.5), 7.7 (1.9, 31.7) and 1.8 (1.2, 2.5) respectively. In contrast farmers who re-entered into a sprayed field, had was equipment and had sprayed 1 day or less were associated with a poor practice score with OR (95% CI) being 0.4 (0.2, 0.9), 0.3 90.1, 0.9) and 0.2 (0.1, 0.6), respectively.

Conclusion: It is important to underline that, poor knowledge and practice of pesticide use were associated with poor working practices. It is recommended that capacity building and training for farmers are initiated to address inadequacies in their knowledge and practice.

Ya-Yun Cheng - Associations of DNA repair genetic polymorphisms and arsenic exposure with bladder cancer in Taiwan

Ya-Yun Cheng
National Cheng Kung University

Background/Aim: Arsenic is well established as a human carcinogen. We conducted a study in southwestern Taiwan to evaluate whether genetic polymorphisms in the NER (ERCC1 Asn118Asn, XPD Lys751Gln, and XPC Ala499Val) and cell cycle pathways (functional STK15 Phe31Ile and p53 Pro72Arg) have associations with bladder cancers related to arsenic exposure.

Methods: We recruited 104 bladder cancers patients and 265 cancer-free controls and collected data on demographics, life style, and environmental factors with a questionnaire. Genotypes were determined using PCR-RFLP. The address of each participant was coded according to the arsenic level in drinking water. The core zone (CZ) included the four townships of the black-foot disease (BFD) endemic area, where the drinking water had arsenic levels above 0.35 ppm. Zone 1 (Z1) included the areas outside the BFD endemic where the drinking water also had arsenic levels above 0.35 ppm, Zone 2 (Z2) included the areas where the drinking water had arsenic levels between 0.1 and 0.35 ppm, Zone 3 (Z3) included the areas where the arsenic levels in drinking water were below 0.1 ppm.

Results: We found that older age, male sex, lower education level, smoking, and arsenic exposure (with dose-response relationship, p<0.05 for test for trend) were risk factors of bladder cancer. Among the NER pathway polymorphisms, we found ERCC1 Asn118Asn was associated with bladder cancer (odds ratio [OR] = 5.4; 95% confidence interval [CI]: 2.7-11.0) after adjusting for the arsenic level in drinking water and other risk factors. Among the cell cycle pathway polymorphisms, we found STK15 Phe31Ile (T>A) mutant type (AA) (OR=2.7; 95% CI: 1.1-7.1) was associated with a higher risk of bladder cancer.

Conclusions: ERCC1 Asn118Asn and STK15 Phe31Ile are associated with bladder cancer in Taiwan, independent of the major environmental risk factor—arsenic exposure from drinking water.

Key Word: arsenic, polymorphism, DNA repair, bladder cancer

Oral abstract presentation: Exposome and DOHaD - Effects of pollutants and other environmental factors

Time: 13:30 - 15:00

Lina Madaniyazi - Early life exposure to indoor air pollutants and the risk of neurodevelopmental delays: the Japan Environment and Children's Study

Dr Lina Madaniyazi
Nagasaki University, Japan

Air pollution has been associated with childhood neurodevelopment. However, the role of indoor air pollution, especially volatile organic compounds (VOCs), on childhood neurodevelopment has been poorly explored to date. We investigated the association between indoor air pollutants and childhood neurodevelopment in 5,017 randomly selected children from the Japan Environment and Children's Study. When the participants reached 1.5 and 3 years of age, they were followed up with home visits and neurodevelopmental tests using the Ages and Stages Questionnaire (ASQ). At both ages, we collected indoor air samples for 1 week and measured 13 indoor air pollutants: particulate matter with an aerodynamic diameter of ≤ 2.5 µm, ozone, nitrogen dioxide, sulfur dioxide, and nine VOCs. The associations between air pollutants and ASQ scores were estimated using linear mixed effects models and weighted quantile sum regressions (WQS) at each age separately. Stratified analysis by sex was conducted. Exposure to m,p-xylene at the age of 3 was associated with lower communication, fine motor, and overall ASQ scores (coefficients: -0.18 [99% confidence intervals (CI): -0.35, -0.02], -0.23 [99%CI: -0.43, -0.03], and -0.72 [99%CI: -1.41, -0.04] per 1 µg/m3 increase, respectively). Exposure to o-xylene at the age of 3 was associated with lower communication, gross motor, fine motor, and overall ASQ scores (coefficients: -0.48 [99%CI: -0.90, -0.07], -0.45 [99%CI: -0.78, -0.13], -0.65 [99%CI: -1.14, -0.16], and -2.15 [99%CI: -3.83, -0.47] per 1 µg/m3 increase, respectively). The WQS index was associated with lower gross motor ASQ scores at the age of 3 (coefficient: -0.27 [95%CI: -0.51, -0.03] for one-unit WQS index increases), which was attributed to benzene (33.96%), toluene (26.02%), o-xylene (13.62%), and ethylbenzene (9.83%). Stratified analysis showed similar results. Although further investigations are required, our results suggest an association of neurodevelopmental delays with indoor low-level exposure to m,p-xylene and o-xylene in early life.

Ka Kei Sum - Air pollution and socioeconomic inequalities in fetal and neonatal growth and adiposity outcomes

Ms Ka Kei Sum
Singapore Institute for Clinical Sciences, A*STAR

Socioeconomic position (SEP) is a major driver to disparities observed in pregnancy, birth, and child outcomes. Using SEP composite indices created from our previous exposome work, we conducted preliminary analyses examining the relationships of SEP and particulate matter exposure during pregnancy with birth and neonatal outcomes.

We performed logistic regression to examine the associations between individual and areal SEP composite indices with pre-term birth, low birth weight, small-for-gestational-age, and large-for-gestational-age using data from the GUSTO cohort in Singapore (N=1096). Associations with gestational age (GA), birth weight (BW), fetal growth velocity estimated by change in estimated fetal weight (EFW) and abdominal circumference (AC) standards, neonatal adiposity measured by air displacement plethysmography (ADP), magnetic resonance imaging (MRI), and sum of skinfold thicknesses were modelled using simultaneous quantile regression with bootstrapped standard errors. Evidence of non-linearities was assessed.

In our unadjusted models, increasing individual composite index (increasing SEP) was associated with 33% (95%CI 0.48-0.94, p=0.02) and 42% (95%CI: 0.40-0.84, p=0.004) less odds in being low birth weight and pre-term respectively. Both individual composite SEP index and PM2.5 exposure during 1st trimester were positively associated with GA at 25th percentile and negatively associated with sum of skinfold thicknesses at 50th and 75th percentile. Meanwhile, change in EFW and AC standards at 75th percentile were negatively associated with individual composite index and positively associated with PM2.5 exposure during 1st trimester. Generally, bigger effect sizes were found at lower quantiles of GA distribution and at upper quantiles of neonatal adiposity and fetal growth velocity distribution. We also observed evidence of quadratic relationships for areal composite index and PM2.5 exposure with multiple neonatal adiposity measures.

Social patterning of birth and neonatal outcomes was evident and more pronounced for those at the lowest GA quantile and higher adiposity quantile in our preliminary analyses.

Samuel Gunther - Prolonged heat exposure and pregnancy outcomes in the tropics

Dr Samuel Gunther
Human Potential Translational Research Programme
NUS Yong Loo Lin School of Medicine

Objectives: Pregnant women and their fetuses are particularly vulnerable to health impacts of extreme heat exposure due to their reduced capacity for thermoregulatory responses. Previous studies have reported associations between heat exposure during pregnancy and higher risk of adverse birth outcomes. We aim to determine the association between prolonged heat exposure and risk of gestational diabetes (GDM) and preterm birth (< 37 weeks' gestation) in Singapore, which is notably different from previous study settings due to its tropical climate and high penetration of air-conditioning usage in domestic, workplace and transportation settings.

Methods: Ethical approval was obtained to access de-identified birth records between 2013 and 2020 from the National University Hospital, which were analysed alongside daily climate records from Changi Airport weather station. Multivariable logistic regression estimated the association between the occurrence of heatwaves (defined as average temperature > 90th-percentile of historical temperatures for at least 3 consecutive days) with GDM and preterm birth, with further analyses stratified by maternal race and parity.

Results: Of the 32,110 singleton live births, 3,010 were to mothers exposed to heatwaves during pregnancy. There was a significant association between heatwave occurrence during the second trimester of pregnancy and higher risk of GDM (RR: 1.23; 95% CI: 1.02, 1.47; p = 0.022), especially in Indian women (1.62 [1.08, 2.39]; 0.017). However, heatwave occurrence during the third trimester was associated with a reduced risk of preterm birth (0.57 [0.39, 0.79]; 0.001). Similar effects were seen in all race and parity groups.

Conclusions: While a heatwave association with GDM has been previously reported, our findings on preterm birth are in direct contrast to previous studies. We speculate that heatwave exposure in Singapore prompts increased air-conditioning use, which could be protective of preterm birth. Our ongoing survey on heat-related behavioural change during pregnancy will provide clarification on potential mechanisms.

Rahel Mesfin Ketema - Mixture of phthalates association to respiratory and allergic symptoms in Japanese children: the Hokkaido Study

Ms Rahel Mesfin Ketema
Hokkaido University
Graduate School of Health Sciences

Background: Phthalates are group of chemicals used as plasticizers mainly in polyvinyl chloride materials. Previous epidemiological studies focused on examining individual phthalates exposure to respiratory and allergic symptoms. However, as humans are exposed to several phthalates simultaneously, examining mixture effect of phthalates is essential for a more real-life exposure assessment.

Objective: We evaluated individual and mixture of phthalate metabolites association with wheeze, rhino-conjunctivitis, and eczema symptoms in Japanese children.

Method: We used demographic and first-morning spot urine samples of 7 years old children from an ongoing Hokkaido birth cohort study (n=400). Wheeze, rhino-conjunctivitis, and eczema were determined using ISAAC questionnaire. Ten urinary phthalate metabolites: MiBP, MnBP, MBzP, MEHP, MEOHP, MEHHP, MECPP, MINP, OH-MINP, and cx-MINP concentrations were measured using LC-MS/MS. Logistic regression for individual metabolites, while mixture effect with Weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were used to investigate the association between phthalate metabolites and symptoms.

Results: Individual logistic regression identified mono (2-ethyl-5-carboxypentyl) phthalate and mono carboxy-isononyl phthalate associated with wheeze. The WQS index showed significant association (OR=1.46, 95% CI 1.09-1.96) with wheeze and (OR=1.40, 95% CI 1.07-1.82) with eczema. Mono-isononyl phthalate (MINP) and mono-(2-ethyl-5-oxohexyl) phthalate were the most highly weighted metabolites respectively. In the BKMR model, diisononyl phthalate (DINP) metabolites showed the highest group posterior inclusion probability (PIP). Among DINP metabolites, MINP in wheeze, cx-MINP in rhino-conjunctivitis and OH-MINP in eczema showed the highest conditional PIPs. Positive trend was observed in the overall mixture of metabolite effect in eczema.

Conclusion: Mixture of phthalate metabolites was associated with wheeze and eczema. More importantly, our findings revealed the primary contributor to the association were metabolites of DINP followed by DEHP. Thus, exposure to phthalates DEHP and DINP may be associated with wheeze and eczema hence reduction of these phthalates exposure in children is warranted.

Athicha Uttajug - Drought and diarrhea among under-5 years children in India

Dr Athicha Uttajug
Hokkaido University

Introduction: High number of deaths due diarrheal diseases among children under 5 years of age has been well-documented in India. Several studies particularly note the role of drought in the spread of diarrheal diseases. Drought decreases water availability and subsequently impacts the population's sanitary practices, which may be indirectly affecting the (population's) diarrheal risk. This study estimated the risk of diarrhea among children exposed to extreme drought in India.

Methods: The prevalence of childhood diarrhea was obtained from India Demographic and Health Surveys (DHS) (2015-2016). Data of drought events and monthly rainfall (2015) were retrieved from DHS geospatial covariate datasets generated by the International Research Institute for Climate Prediction and Japan Aerospace Exploration Agency (JAXA), respectively. Extreme drought exposure was coded using the top three deciles of the Weighted Anomaly of Standardized Precipitation index (WASP) during 2015. The association between the prevalence of diarrhea among under-5year old children and extreme drought was assessed by multivariable logistic regression after adjusting for monthly average temperature, monthly rainfall, age, source of drinking water, toilet quality, and residence area type.

Results: Among the 133,571 children under 5 years of age included in the survey (year 2015), approximately 9% reported having diarrhea within the 2 weeks prior to the survey. We found that extreme drought was significantly associated with the prevalence of childhood diarrhea [Odds Ratio (OR) = 1.11 (95% Confidence Interval (CI): 1.05, 1.17)], while improved drinking water source and toilet quality reduced the risk of childhood diarrhea.

Conclusions: Our findings suggest that extreme droughts significantly increase the risk of diarrhea among under-5-year-old children in India. Given that extreme drought events are expected to increase with changing climate, it is important to understand role of drought in amplifying childhood diarrheal risks, and similarly how improved sanitation and hygiene reduces such risks in India.

Oral abstract presentation: Built/indoor environment and health

Time: 15:00 - 16:30

Yu-Chuan Yen - Personal exposure and household indoor concentrations of formaldehyde and aldehyde for schoolchildren in Taiwan

Dr Yu-Chuan Yen
National Institute of Environmental Health Sciences
National Health Research Institutes

Formaldehyde and aldehydes are common air pollutant that tends to be found in elevated concentrations in indoor air. Exposure to formaldehyde can induce respiratory health outcomes, particularly in school-aged children. Children spend most of their time indoors at home, but the contribution of formaldehyde and aldehyde concentrations in homes to personal exposure in children is limited. The factors associated with aldehyde exposures in children are still not clear. This study aimed to investigate personal exposure and indoor home concentrations of aldehydes for elementary school children and to evaluate their exposure determinants.

We recruited 40 schoolchildren (aged 8-10 years) in Taiwan's urban city for aldehydes measurements. We conducted personal monitoring with the passive sampling (Radiello™ Cartridge Adsorbents) and active sampling with dinitrophenylhydrazine (2,4-DNPH) (LpDNPH S10 Cartridge, Supelco Inc., Bellefonte, PA, USA) in the warm and cold seasons. Nine aldehyde compounds were analyzed using the HPLC. We also collected questionnaires from the subjects' parents to record household and personal exposure information during the samplings. We assessed the within- and between-subject variability in aldehyde concentrations and evaluated the factors affecting exposure using a mixed-effects model.

The highest mean level of personal exposure among 9 aldehydes was formaldehyde (AM = 14.7 μg/m3; GM = 12.9 μg/m3). Aldehydes in home indoor were significantly correlated with personal exposure, except for acrolein and isovaleraldehyde. The within-subject variance accounting for 66.6%-100% of the total variance in concentrations was obtained for selected aldehydes. There were moderate to high correlations between aldehydes in personal exposure, except for benzaldehyde and isovaleraldehyde. As compared with guideline values of the ATSDR, formaldehyde and acrolein in exposure concentrations were highly concerned, with 93.6% and 100% of overexposure, respectively. Season, photocopier use, and household formaldehyde significantly affected personal exposure levels of formaldehyde.

Xiaorong Yang - Spatio-temporal patterns of lung cancer burden attributable to residential radon in 204 countries and territories, 1990-2019: Results from the Global Burden of Disease Study 2019

Dr Xiaorong Yang
Shandong University

Understanding the latest global spatio-temporal pattern of lung cancer burden attributable to residential radon exposure is crucial to prioritize global lung cancer prevention, as well as indoor environment improvement.

Data on lung cancer attributable to residential radon exposure were obtained from the Global Burden of Disease Study (GBD) 2019. The age-standardized rates of lung cancer mortality (ASMR) and disability-adjusted life years (ASDR) were estimated by age, sex, region, and country. Estimated annual percentage change (EAPC) was used to quantify the temporal trends of ASMR and ASDR from 1990 to 2019.

In 2019, the total number of global lung cancer deaths and DALYs attributable to residential radon was approximately 83,703 and 1.89 million respectively, with 1.76- and 1.55-fold increase as compared to 1990, while the global ASMR and ASDR decreased with EAPC of -0.63 (95% CI: -0.68, -0.58) and -0.99 (95% CI: -1.04, -0.95), respectively. The ASMR of radon-related lung cancer was highly associated with the sociodemographic index (SDI), especially among the countries and territories with SDI less than 0.7 (Spearman correlation: ρ = 0.413, P = 8.0 x 10-10). From 1990 to 2019, the largest EAPC in ASMR was observed in Bulgaria (1.94, 95% CI: 1.42, 2.48), and the EAPC exceeding 1 was also observed in 17 other countries and territories, although most had achieved successful radon-related lung cancer control over the past three decades. In addition, the high radon-related lung cancer burden rate was mainly observed among men and the elderly.

The number of residential radon-related lung cancer deaths and DALYs has increased substantially from 1990 to 2019, especially in low to middle SDI regions. To reduce radon-related burden, local governments should make targeted efforts, such as regular radon monitoring and ventilation improvements, especially in areas with high or rising radon exposure.

Undarmaa Enkhbat - Portable HEPA Filter Air Cleaner Use During Pregnancy and Children's Autistic Behaviors at Four Years of Age: The UGAAR Randomized Controlled Trial

Ms Undarmaa Enkhbat
Mongolian National University of Medical Sciences
Simon Fraser University

Background: Developmental exposure to particulate matter (PM) air pollution may increase children's risk of developing autism spectrum disorder. We quantified the impact of reducing PM exposure during pregnancy using portable air cleaners on the development of autistic traits in children. We also assessed associations between indoor fine PM (PM2.5) concentrations during pregnancy and autistic traits.

Methods: In this single-blind, parallel-group randomized controlled trial in Ulaanbaatar, Mongolia, we randomly assigned 540 non-smoking pregnant women to receive HEPA filter air cleaners or to a control group, which did not receive air cleaners. We administered the Social Responsiveness Scale, Second Edition (SRS-2) to caregivers when children were a median of 48 months (range: 48 to 51 months). Our primary outcome was the SRS-2 total T-score. We imputed missing data using multiple imputation with chained equations and our primary analysis was by intention to treat. In a secondary analysis, we estimated adjusted associations between PM2.5 concentrations inside residences and SRS-2 T-scores.

Results: We enrolled participants at a median of 11 weeks' gestation. After excluding miscarriages, still births, and neonatal deaths, our analysis included 478 children (233 control and 245 intervention). We observed no differences in mean SRS-2 scores between treatment groups. In secondary analyses, an interquartile range (9.6 µg/m3) increase in indoor PM2.5 during pregnancy was associated with 1.8-unit (95% CI: 0.3, 3.2) increase in mean SRS-2 total T-score.

Conclusion: We found no benefit of reducing indoor PM during pregnancy on parent-reported autistic traits in children. In secondary analyses, however, indoor PM2.5 concentrations were associated with higher autism trait scores among 4-year-old children. These exploratory findings suggest that exposure to air pollution during pregnancy may influence the development of autistic traits in childhood.

Sun-Young Kim - An approach to assessing indoor fine particulate matter air pollution for epidemiological studies

Dr Sun-Young Kim
National Cancer Center

Objectives: While there has been accumulating evidence of the association between long-term exposure to fine particulate matter (PM2.5) and health endpoints, one of the key limitations was suggested as exposure assessment relying on outdoor PM2.5 measurements. A significant difference between outdoor and indoor air quality found in numerous studies could subsequently affect health effect analyses. The impact could be even larger for patients with chronic diseases who spend most of the time indoors. Although the assessment of long-term exposure to indoor PM2.5 is critical to understand the prognosis of chronic diseases associated with PM2.5, most studies focused on short-term monitoring limited in time and space. We aim to develop an approach to assessing long-term exposure to indoor PM2.5 at homes of Idiopathic Pulmonary Disease (IPF) patients for epidemiological application.

Methods: We design our indoor monitoring campaign to obtain 24-hour samples of PM2.5 over different hours, days of the week, and seasons during a year in approximately 100 IPF patients who visit the Asan Medical Center in South Korea for 2021-2023. Using RTI MicroPEM, a low-burden real-time PM sensor, we measure indoor PM2.5 concentrations for five days including both weekdays and weekends in each of the four seasons. In addition, to compare indoor and outdoor PM2.5, we install samplers outside the balconies of 20 percent of patients' homes. The sampling days are scheduled within the maximum 4 weeks of patients' medical examinations. Patients also perform home spirometry twice a day during the sampling period.

Results: Our preliminary findings for indoor PM2.5 samples in 2021 showed hourly, weekly, and seasonal patterns with some variation by patients. PM2.5 concentrations were generally higher in morning and evening hours, on the weekends, and in fall.

Conclusions: Our exposure assessment approach of indoor PM will provide a practical guidance for future epidemiological studies of PM2.5.

Nai-Tzu Chen - The burden of disease attributable to time-weighted average of PM2.5 exposure: outdoors, public spaces, and homes

Dr Nai-Tzu Chen
National Cheng Kung University

Background: People spend >80% of their time indoors, including homes and public spaces. However, most studies evaluating health impacts attributable to PM2.5 were based on outdoor exposure. Therefore, this study aims to calculate the attributable health burden to PM2.5 by simultaneously considering indoor and outdoor exposure.

Methods: Outdoor PM2.5 levels from 2013-2014 were generated using a land-use regression model with machine learning from Taiwan EPA's data, which were also utilized to calculate PM2.5 levels indoors based on indoor/outdoor (I/O) ratios. I/O ratios of public spaces and homes were collected from Taiwan EPA and our previous survey, respectively. Data of outdoors, homes, and public spaces were applied to calculate the time-weighted average of PM2.5 exposure to represent the overall PM2.5 exposure in each city, which were linked to the corresponding RRs on ischemic heart disease (IHD), stroke, and chronic obstructive pulmonary disease (COPD), and the mortality and morbidity of diseases to estimate the attributable disability-adjusted life year to PM2.5 (DALYs_PM2.5). RRs of PM2.5 on diseases and disease outcomes were extracted from a Lancet study and Taiwan's Longitudinal Health Insurance Database.

Results: The DALYs_PM2.5 was the highest for IHD, followed by stroke and COPD (1090, 927, 530 DALYs per million people). IHD and stroke both gave the larger contribution of years of life lost (YLL) to DALYs_PM2.5 than years lived with disability (YLD), whereas COPD showed an opposite finding. For IHD, DALYs_PM2.5 was the highest in Taipei (190) and the lowest in Hualien (20). Kaohsiung had the greatest DALYs_PM2.5 of stroke and COPD (149 and 78 DALYs per million people, respectively). The lowest DALYs_PM2.5 of stroke and COPD were Hsinchu County and Hualien, respectively.

Conclusions: Cardiovascular diseases had higher DALYs_PM2.5 than respiratory disease, and revealed a greater contribution of YLL to DALYs_PM2.5. Besides, urban cities showed the greater DALYs_PM2.5 regardless of diseases.

Day 2
Tuesday, 21 June 2022
Auditorium 1

Plenary Session 3: Changing Environment and Health

Time: 9:00 - 11:00

Impacts of Developmental Exposure to Environmental Chemicals on Human Health: The Hokkaido Birth Cohort Study with Global Perspective

Reiko KISHI, MD., PhD., MPH.
Hokkaido University, Center for Environmental and Health Sciences

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort.

Our primary objectives are to
(1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including congenital malformation and growth retardation;
(2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development;
(3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and
(4) identify the additive effects of various chemicals, including tobacco. The purpose of my speech is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions.

The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects under current folate intake levels. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies.

Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of the Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. Our study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.

Changing environment and health

Assoc Prof Xiaoqi Feng
University of New South Wales

How environments of contrasting types and scales affect health has long been of great interest to epidemiologists and fellow researchers in related disciplines (e.g. health geography). With increasing recognition that climate change is the number one threat to public health in the 21st century, it is pertinent for us to consider how changing environments shape health trajectories over the lifecourse and across generations. In my presentation, I will outline some of the many ways that the intragenerational and intergenerational health impacts of changing environments have already been studied. I will finish the presentation by seeding discussion with some ideas for future environmental epidemiological studies of changing environment and health.

Climate change impacts on human health and performance - Combined need for environmental epidemiology and health impact assessment

Prof Tord Kjellstrom
National Centre for Epidemiology and Population Health, Australian National University
Health and Environment International Trust

A key feature at the Earth Summit in Rio de Janeiro in 1992 was the need to reduce climate change. Human health effects and related social and economic impacts were a major concern as reported by the WHO in 1996. After this year numerous reports provide evidence about the likely effects, including heat exhaustion, cardiovascular disease, vector-borne diseases, diarrhoeal diseases, nutritional deficiencies, injuries and mental health. Heat exhaustion reduces labour capacity which creates social and economic impacts, and it reduces opportunities for health promoting physical activity outdoors. In 2009 the journal Lancet concluded that climate change was the greatest global public health threat this century. The underlying environmental factors include increasing heat, extreme weather events, reduced access to safe drinking water, reduced local food production, changing vector ecology, and mental stress due to dislocation.

Scientific evidence linking climate variables to these effects is still insufficient and environmental epidemiology has an essential role to play. The cause-effect relationships between climate factors and specific physiological or clinical health effects needs quantification in different settings and population groups by age, sex, etc. The quantified relationships need to be designed to fit the needed inputs into environmental health impact assessments, so that decision-makers can choose the most appropriate and effective policies and actions to protect health and well-being of populations.

Recent initiatives to communicate the health risks include the Lancet Countdown indicators and data from WHO, IPCC and the recently established Global Heat Health Information Network (GHHIN). But there is room for improvement and environmental epidemiologists are the key scientists to get involved. Large parts of Asia are already substantially affected by high heat levels, extreme weather or other environmental shocks, so, the future work of participants in this conference is essential for producing new evidence that guides climate policy decisions.

Auditorium 1

BiCCA Cohort Symposium: Exposure to environmental chemical mixture and maternal and child health in Asia

Time: 11:00 - 12:30

The threat of environmental pollutants to human health has changed along with regulations and policies. The traditional exposure science as the exploration of specific single chemicals may not be comprehensive in the real world. Multi-pollutants approach that consider the environmental chemical mixture and alternatives are especially crucial to vulnerable fetus and children. Moreover, the burden of environmental threats to children is unevenly distributed and varies by industrialization status, life style and genetic susceptibility.

In this symposium, we would like to provide the latest evidences related to environmental hazards to maternal and child health in birth cohort studies in China, Japan and Taiwan, focusing on environmental chemical mixture and emerging alternatives. From the life course perspective, reproductive health will be reported first. Shanghai Birth Cohort is a couple-based prospective cohort study with the strength of the design to explore the health and conception status of women of reproductive age. Twenty-one legacy and emerging per- and polyfluoroalkyl substances (PFAS) were quantified. The Bayesian kernel machine regression (BKMR) model showed that PFAS mixture was significantly positively correlated with Transforming Growth Factor Beta (TGF-β) and negatively correlated with Interleukin-10 (IL-10). And, urinary concentrations of multi-class phenols in couples were measured during preconception period. No joint effects of phenols mixture on couple fecundity were observed. However, Parabens exposure in female partners was found to be associated with reduced fecundity. Second, behavior problems in preschool-aged children were assessed by caregiver-reported DSM-oriented scales of the Child Behavior Checklist (CBCL) in the Taiwan Maternal and Infant Cohort Study. Prenatal exposure to dibutyl phthalate, Copper (Cu), cadmium (Cd), and Lead (Pb) were found to be associated with certain domain of DSM-oriented scales in children at 4 years of age. In addition, prenatal co-exposure to PAEs and the metals significantly associated with autism spectrum disorders in children. Finally, two studies focused on childhood allergic diseases, as assessed by The International Study of Asthma and Allergies in Childhood (ISAAC) Questionnaires. Children in the Hokkaido Study had their urinary concentrations of phthalates, phosphate flame retardants and plasticizers (PFRs), bisphenols, and nonylphenol (NP) measured at age 7. Trends in exposure to these chemicals from 2012 to 2017 were compared. Positive association were found between oxidative stress markers and mixture of PFR metabolites and NP, but not with other chemicals. Meanwhile, single metabolite and mixture of phthalates were positively associated with increased risk of wheeze and eczema of 7 years old children. In a Chinese Child Home and Health study, indoor concentrations of phthalates in dust and phthalate metabolites in urine in children aged 0-8 were measured. Indoor building decoration materials as well as Di-isobutyl phthalate (DiBP) and Mono-2-ethylhexyl phthalate (MEHP) have been found to increase the risk of asthma and rhinitis.

Through the above themes, threats from chemical mixture and emerging alternatives have been identified from preconception period to childhood. Further collaboration is required to elucidate the distribution of these environmental pollutants in Asia.

Junjie Ao - Pre-conception exposure to environmental phenols and couple fecundity: a couple-based prospective cohort study

Asst Prof Junjie Ao
Ministry of Education
Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine

Phenols are widely applied in commercial products and known for the toxicities on reproduction. Evidence regarding the associations of exposure to phenols during the critical pre-conception period with couple fecundity was inconsistent and scarce. We aimed to investigate the effects of multi-class phenols on couple fecundity using multiple statistical models in a couple-based prospective cohort study. A total of 884 couples who participated in the Shanghai Birth Cohort between 2013 and 2015 were included. Concentrations of 13 phenols, including 7 bisphenols and 6 parabens, were measured in the urine samples collected form couples. The outcomes included couple fecundability (time-to-pregnancy (TTP)) and infertility (TTP>12 menstrual cycles). Partner-specific and couple-based models were applied to estimate the associations. Elastic net regression (ENR) was used to select dominant phenols. Exposure patterns of phenols were simulated by principal components analysis (PCA). Bayesian kernel machine regression (BKMR) and quantile-based g-computation (q-gcomp) were applied to estimate the joint effects of phenols mixture on couple fecundity. A total of 525 couples (59.4%) conceived naturally. In partner-specific models, bisphenol A (BPA), propyl paraben (PrP) and butyl paraben (BuP) from female partners were associated with reduced fecundability and increased infertility risk. In couple-based models, BuP from female partners was significantly associated with a 13% reduction in fecundability (fecundability ratio (FR)=0.87; 95% confidence interval (CI): 0.83, 0.91) and a 22% increased odds of infertility (odds ratio (OR)=1.22; 95% CI: 1.11, 1.33). A protective effect on infertility was found for BPZ from female partners. PCA showed that the parabens exposure in female partners was significantly associated with an increased risk of infertility by 32% (OR=1.32; 95% CI: 1.05, 1.65). Joint effects of phenols mixture on couple fecundity were non-significant. Phenols exposure in male partners did not seem to affect couple fecundity. Parabens exposure in female partners was associated with reduced couple fecundity.

Min Nian - Emerging and Legacy PFAS and Cytokine Homeostasis in Women of Childbearing Age

Dr Min Nian
Ministry of Education
Shanghai Key Laboratory of Children's Environmental Health, School of Public Health, Shanghai Jiao Tong University School of Medicine

The effect of legacy and emerging per- and polyfluoroalkyl substances (PFAS) on cytokine homeostasis in human remains poorly understood. This study aimed to evaluate the associations between legacy and emerging PFAS and cytokine profiles, and identify the main contributors to the disturbance of cytokine homeostasis. We quantified 21 PFAS in 198 Chinese women of childbearing age from 2015 to 2016. 13 cytokines were measured using the Meso Scale Discovery U-PLEX and V-PLEX platforms. The associations between PFAS exposure and cytokine levels were assessed using multiple linear regression (single-exposure), and Bayesian kernel machine regression (BKMR) models (PFAS mixture exposure). In single PFAS models, legacy and alternative PFAS were positively associated with Th1 and Treg cytokines, and negatively associated with Th2 and Th17 cytokines. For instance, each ln-unit increase in 6:2 chlorinated perfluoroalkyl ether sulfonic acid (6:2 Cl-PFESA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonate (PFOS) was associated with a decrease in IL-10 by -0.228 (95% CI: -0.336, -0.120), -0.153 (95% CI: -0.277, -0.030), and -0.174 (95% CI: -0.339, -0.010), respectively. The BKMR model showed a significantly positive association of PFAS mixture with TGF-β and a negative association with IL-10. Overall, these results indicate that both legacy and emerging PFAS may affect the homeostasis of cytokines.

Atsuko Ikeda-Araki - Children's multiple chemical exposures: The Hokkaido Study on Environment and Children's Health

Dr Atsuko Ikeda-Araki
Faculty of Health Sciences
Hokkaido University, Japan and Center for Environmental and Health Sciences, Hokkaido University

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes since 2001: the Sapporo cohort and the Hokkaido cohort. In previous studies, we have published our findings of prenatal exposures to polychlorinated biphenyls, dioxins, organochlorine pesticides, per-and polyfluorinated compounds, and phthalates and various health outcomes. Chemical exposure to children can occur both before and after birth. Postnatal exposure to environmental chemicals may from interior areas, diet, and consumer products. Thus, we have been conducting exposure measurements of children. When participating children of the Hokkaido Study becomes 7 years old, we have asked them to collect morning void urine samples to investigate the current internal exposure levels of shorter half-life compounds or their metabolites: phthalates, phosphate flame retardants and plasticizers (PFRs), bisphenols, and nonylphenol (NP). At the same time, we measured oxidative stress 8-hydroxy-2'-deoxyguanosine and lipid peroxidation biomarkers N-ε-hexanoyl-lysine (HEL) and trans-4-hydroxy-2-nonenal (HNE). We have also examined the prevalence of asthma and allergies by ISAAC questionnaire. When comparing the levels of these chemicals in the urine collected from 2012 to 2017, increasing secular trend of PFRs and BPS was found, while decreasing trend in BPA and NP. Furthermore, the levels of phthalates did not show any secular trends during the study periods. Mixture of PFR metabolites and NP were positively associated with levels of HEL and HNE, whereas phthalates metabolites and bisphenol levels did not show any clear associations with these markers. Finally, single metabolite as well as mixture of phthalates were positively associated with increased risk of wheeze and eczema of 7 years old children. For further examination and follow-up, we are now conducting face-to face health check-up with blood and urine sample collections at one's adolescence.

Tsung-Lin Tsai - Prenatal exposure to phthalates, metals and mental diseases in children at age 4 years - Taiwan Maternal and Infant Cohort Study

Dr Tsung-Lin Tsai
National Institute of Environmental Health Sciences, National Health Research Institutes

Introduction: About 10%-20% of children and adolescents suffer from mental health problems worldwide, and it may be increasing the global burden of disease. Prenatal phthalates (PAEs) and neurotoxic metals (such as As, Cd, and Pb) are considered being risk factors of child behavior development and mental health. However, the effect of co-exposure to metals, PAEs, and the association with child behavior is less well studied. We aimed to investigate prenatal co-exposure to PAEs and metals and the consequent outcome of behavior in early childhood.

Method: A total of 591 participants from the Taiwan Maternal and Infant Cohort Study were followed-up with 2015-2017. We quantified the maternal urinary concentration of metabolites of PAEs and metals as prenatal exposure. Child behavior problems at age four years were according to caregiver-reported DSM-oriented scales of the Child Behavior Checklist (CBCL). Finally, there were 283 children with complete variable data included in further analysis.

Results: Maternal urinary concentration of MiBP was significantly associated with increased odds of depressive disorder (OR=1.71, p=0.01) in children. Increased maternal urinary Cu also significantly associated with increased odds of depressive (OR=2.30, p=0.03), attention-deficit/hyperactive (OR=2.31, p=0.04), and oppositional defiant (OR=1.97, p=0.03) disorders in children. Increased maternal urinary concentration of Cd and Pb was significantly associated with attention-deficit/hyperactive (OR=2.55, p=0.01), and oppositional defiant (OR=1.69, p=0.03) disorders, respectively. In the further analysis, prenatal co-exposure to PAEs the metals significantly associated with autism spectrum disorders in children (OR=4.90, p=0.03).

Conclusion: We observed that prenatal exposure to dibutyl phthalate, Cu, Cd, and Pb associated with certain DSM-oriented disorders in children at 4 years of age. Also, prenatal co-exposure to PAEs and metals may play a certain role in children's mental health. Reduction of exposure to PAEs and metals in pregnancy is suggested for the prevention of increased behavior or mental problems in childhood.

Yuexia Sun - Modern chemical compounds in indoor environment make child allergic

Assoc Prof Yuexia Sun
Faculty of Health Sciences
Tianjin University

In recent decades a significant increase in the development and production of synthetic chemicals has been observed, impacting many aspects of human life and the natural environment. During the same period of time as the exposure for these new chemicals has increased there has been a remarkable increase in several chronic diseases/disorders such as asthma and allergy among children.

Phthalate esters which are one of the Semi-Volatile Organic Compounds (SVOCs), are widespread in the interior environment and are mostly employed as plasticizers in industrial items and everyday necessities such as chemical products and building materials.

We launched a Chinese Child Home and Health study to evaluate the associations of daily consumer products with indoor concentrations of phthalates in dust and phthalate metabolites in urine, the influence of indoor environmental factors on phthalates exposure, and the health effects of phthalates (and their urinary metabolites) on children's (0-8 years old) asthma and allergy.

We found that DEHP (126.94 µg/g), DnBP (40.82 µg/g), and DiBP (16.27 µg/g) were the most common indoor dust phthalates, and they were linked to chemical products and building materials, with the median phthalate concentration in urban/affluent households being higher than in rural/poor homes. Indoor phthalates exposures were linked to total intakes of phthalates indicated by their metabolites in urine. DiBP and doctor diagnosed asthma (odds ratio, 1.31(1.10-1.56)), and MEHP and current rhinitis (1.40(1.08-1.82)) showed positive statistically significant associations, implying that DiBP and DEHP were risk factors for asthma and rhinitis, respectively. Our data also revealed that, building materials and chemical products had positive relationships with asthma and allergies, and these associations were statistically significant in many circumstances.

Our findings suggested that indoor building decoration materials and chemical products were the sources of phthalates released, which have been associated with the health problems among children.

ISES Symposium: Opportunities and challenges of exposure factors as key techniques of environmental exposure assessment

Time: 13:00 - 14:30

Exposure factors are the basic parameters used to describe the behavior and characteristics of human exposure to environmental pollution and are the key factors to determine the accuracy of environmental health risk assessment. These key factors for evaluating population exposure and health risk of environmental pollutants are of great significance for further research on environmental and human health impacts. Exposure factors are dynamic and constantly changing with advances in exposure science and technology as well as changes in human behavior and activities. Existing exposure factor manual data need to be continuously updated to improve the scientific quality and accuracy of exposure assessment. Therefore, this symposium will focus on the research focus of exposure factor data source, data format and availability, the development of susceptible population data, innovation of investigation methods, etc., while focusing on the variability and uncertainty of exposure factors, discuss the development and challenges of exposure factors. Furthermore, the important role of exposure factors in providing data support for the government to formulate technical guidelines to protect the health of the population was further discussed.

Zhaomin Dong - Global exposure to per- and polyfluoroalkyl substances and associated burden of low birthweight

Zhaomin Dong
Beihang University

The aim of this study is to comprehensively evaluate the impact of Per- and polyfluoroalkyl substances (PFAS) exposure on the global burden of Low birthweight (LBW). Specifically, the objectives of this study were: 1) to establish a global dataset for the biomonitoring of PFAS; 2) to address spatiotemporal trends in PFAS exposure; and 3) to estimate the LBW burden attributable to PFAS exposure. Firstly, two types of data were collected: systematic literature extraction of biomonitoring data on PFAS exposure in humans and global LBW data from existing publications and national surveys. Secondly, evaluate the spatiotemporal trends of PFAS exposure and estimate the daily intake of PFAS by using the toxicokinetic model, expressed in the first-order form. Finally, a meta-analysis was implemented based on literature survey to calculate the dose-response curve between perfluorooctanoic acid (PFOA)/perfluorooctanesulfonic acid (PFOS) exposure and birthweight. The LBW incidence attributable to PFOA exposure was evaluated using the dose effect curve of PFOA and birthweight. Global exposure to PFOS was the highest, followed by the PFHxS and PFOA. Spatiotemporal exposure to PFAS varied considerably, with daily intake estimated in the range of 0.01-1.7 ng/kg/day. Moreover, decreasing trends in PFOS, PFHxS and PFOA exposure were noted in most regions of the world over the past two decades, but such trends were not observed for other PFAS with long carbon chains, especially in East Asia. Furthermore, we estimated that human exposure to PFOA contributed to approximately 461,635 cases per year of low birthweight during the past two decades, predominantly from Asian regions. Although our estimation may be constrained by uncertainties from dose-response curve and data availability, this study has unveiled that PFOA exposure might be a contributor (relative allocation was about 2.2%) to the worldwide LBW cases, thus supporting actions to mitigate PFAS contamination.

Mingliang Fang - Quantification of exposome (Chemicals)

Mingliang Fang
Fudan University

Due to the ubiquitous use of chemicals in modern society, humans are increasingly exposed to thousands of chemicals. Here, we compiled a human exposome database of more than 20,000 chemicals, prioritized 13,441 chemicals based on probabilistic hazard quotient and 7,770 chemicals based on risk index, and provided a predicted biotransformation metabolite database of >95,000 metabolites. In addition, a user-interactive JAVA based search GUI was generated to enable open access to this new resource. We further developed one stable-isotope labeling platform to effectively quantify those exposures in a high-throughput and cost-effective manner.

Sai Li - Long-term exposure to PM2.5 and children's lung function: A dose-based association analysis

Sai Li
University of Science and Technology Beijing

The current literature on the effects of long-term exposure to PM2.5 and children's lung function is inconsistent, in part due to inadequate or inaccurate exposure assessments. In this study, we recruited 898 participants of 7-12 years old from the city of Lanzhou located in northwestern China. Participants underwent spirometric tests for lung function and responded to a questionnaire survey. Detailed information about individual air exposure and personal information was collected. Combining spatial distribution of PM2.5 concentrations in the past five years and individual time-activity data, we estimated annual ADD for 5 years preceding the lung function tests and 5-year average ADD, respectively. We used multiple linear regression models to examine the associations between ADD values and lung function, controlling for a range of individual-level covariates. The 5-year average ADD among all the participants was 50.5 µg/d-kg, with higher values estimated for children living in the urban area and children whose parents received a lower education attainment. We found that a 1 µg/d-kg increment in ADD of PM2.5 was associated with a 10.49ml (95% CI: -20.47, -0.50) decrease in forced vital capacity (FVC) and a 7.68ml (95% CI: -15.80, -0.44) decrease in forced expoloratory volume in 1 second (FEV1). Among the annual ADDs estimated for the preceding 5 years, the immediate prior one year of lung function measurement had the greatest effect on lung function. The effect was stronger in girls than in boys. However, we found no associations between yearly level of PM2.5 and lung function when defined concentration was used as an exposure variable. Long-term PM2.5 exposure, when estimated as exposure dose averaged over a year or longer, was associated with statistically significant reductions in FVC and FEV1 in children of elementary-school age. Future studies may consider the use of individual-level dose estimates to improve the dose-response assessment.

ISES Symposium: Rising Stars in Exposure and Health Symposium

Time: 14:30 - 16:00

Hein Min Tun - The mediation role of infant gut microbiome and immunity in the association between maternal smoking during pregnancy and childhood overweight

Asst Prof Hein M. Tun
School of Public Health
LKS Faculty of Medicine
University of Hong Kong

Obesity affecting over 18% of children and adolescents has been linked to maternal smoking during pregnancy. However, the complex mechanism involving gut microbiota, their metabolites, and associated immunological changes in this association is yet to be identified. In a large birth cohort study, we confirmed a dose-response association between maternal smoking during pregnancy and BMI z-scores of infants. Besides, quitting smoking or reducing the number of cigarettes during pregnancy cannot lower the risk of childhood overweight. Using a multi-omics approach, we identified an increased abundance of Firmicutes species and its diversity in children exposed to maternal smoking during pregnancy, reflecting their gut microbiota mature faster than that of non-exposed counterparts. Furthermore, fecal butyrate concentration and associated microbial pathways were higher in children whose mothers smoke during pregnancy. In addition, their gut microbiomes are enriched by IgA-degrading Sutteralla, resulting in low stool IgA levels. Our findings also indicated that the abundances and diversity of Firmicutes species mediate the elevated risk of childhood overweight linked to maternal prenatal smoking through excessive butyrate production and IgA degradation. Thus, pregnant women should avoid tobacco smoking to prevent microbiome-mediated overweight risk in offspring.

Inae Lee - Exposure to phthalates and alternative plasticizers among susceptible populations: current levels of exposure and intra-personal variation

Dr Inae Lee
Seoul National University

[Background and objectives ] The traditional phthalate, di(2-ethylhexyl) phthalate (DEHP), is widely used as a plasticizer. Due to its toxicity and regulation, it has been replaced by alternative plasticizers. We aimed to investigate the current levels of exposure to major traditional and alternative plasticizers among susceptible populations of children and adult patients. In addition, temporal variation over time was also observed.

[Methods] Children were recruited from elementary schools of Saudi Arabia (n=109), Thailand (n=104), and Indonesia (n=89) in 2017-2018. In addition, adult patients with chronic kidney disease were recruited in 2020-2021 (n=306), and their repeated urine samples were collected for three times. Metabolites of major phthalate and alternative plasticizer were measured in the urine samples by HPLC-MS/MS.

[Results] Exposure profile was clearly different among children of three countries. Urinary levels of diisononyl phthalate (DiNP), diisodecyl phthalate (DiDP), di-2-ethylhexyl terephthalate (DEHTP), and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH)) metabolites were the highest in Saudi children. DINP metabolites were also highest in the children of Indonesia but those of non-phthalate metabolites were low. Among the adult patients, the urinary concentrations of most metabolites exhibited ICCs ranging 0.2-0.6 (n=248), indicating weak to moderate reproducibility over time. Most of urinary levels of phthalates and alternative plasticizers in the adult patients were relatively lower than those in children from three Asian countries.

[Conclusions] Priority plasticizers that were identified, in particular, among Saudi children warrant refined exposure assessment for source identification and relevant exposure reduction measures.

[Acknowledgement] This work was supported by grants from National Research Foundation of Korea (NRF) (NRF-2020R1A2C3011269 and NRF-2022R1C1C2006982).

Xia Meng - Health studies and exposure assessments promoted by big data in air pollution

Assoc Prof Xia Meng
School of Public Health
Fudan University

Air pollution and its health effects have been rising broad concerns from scientists, physicians and policy makes worldwide. In the past decades, data enrichment and method (model) development have greatly contributed to understand the knowledge of air pollution and its health effects on population. In recent years, increasing open-access database and applications of advanced modelling methods (e.g. machine learning algorithm) lead us to the big data era. In the big data era, the data sources of heath and environmental factors are wider, the resolutions of these data are finer, and the collaborations among disciplines and countries are closer. In this talk, first, I would introduce a global study based on the Multi-Country Multi-City (MCC) collaborative research network. By including 398 cities from 22 countries/regions, we found that 1) short-term exposure to ambient nitrogen dioxide (NO2) is associated with increment of mortality, 2) the association is almost linear and without significant threshold, and 3) the effect is likely to be independent from other air pollutants. The results have contributed evidence in this direction and been cited in the Air Quality Guidelines launched by the World Health Organization in 2021. Second, I would introduce a series studies developed based multiple data sources and machine learning method to evaluate long-term trends of major ambient air pollutants with high resolutions. Daily concentrations of PM2.5 and ozone at 1km spatial resolution are estimated at mainland China since 2005. Based on the exposure database, we found that PM2.5 decreased sharply since 2013, while ozone tended to increase in China. The peak-season ozone pollution with the highest 6-month ozone concentrations occurred in different months among regions, with more than half domain in April-September. The high-resolution exposure data can support high-quality epidemiological studies and provide information to understand the spatiotemporal characteristics of air pollution.

Weiyue Hu - Effects of glufosinate-ammonium on male reproductive health: Focus on epigenome and transcriptome in mouse sperm

Dr Weiyue Hu
School of Public Health
Nanjing Medical University

Glufosinate-ammonium (GLA) is a widely used herbicide with emerging concern over its reproductive toxicity. To uncover potential effects of GLA on male reproductive health in mammals, adult male C57BL/6J mice were administered 0.2 mg/kg·d GLA for 5 weeks, and then copulated with female DBA/2 mice. After examination on fertility, testis histology and semen quality in the GLA group, we performed deep sequencing to identify DNA methylation, transcriptionally active (H3K4me3 and H3K27ac) and repressive (H3K27me3 and H3K9me3) histone modifications, and mRNA transcript levels in sperm. Moreover, RNA sequencing was also performed on preimplantation embryos to reveal whether these histone modification alterations would cause any abnormal gene expression after fertilization. We found no significant abnormality either on fertility, testis histology or semen quality-related indicators in GLA mice. Next generation sequencing showed alterations of these epigenetic marks and extensive transcription inhibition in sperm. Differential active marks were enriched at promoters and putative enhancers, while repressive marks were mainly distributed at intergenic regions and introns. They were mainly enriched in pathways related to synapse organization. When we zoomed in these regions, increased H3K4me3 overlaps H3K27ac loci at the gene promoter of Phkg2, which was actively expressed in GLA sperm. Additionally, decreased H3K4me3 overlaps H3K27ac at the promoter of Dcn in sperm, which was also down-regulated in GLA preimplantation embryos. These results suggested that GLA predominantly affected sperm epigenome and transcriptome, with little effect on fertility, testis histology or semen quality. These alterations in sperm epigenetic marks were concordant with gene expression in preimplantation embryos, which might further affect embryo development and offspring health. Further studies still need to be conducted for a better understanding of the male reproductive toxicity of GLA.

ISES Symposium: Intergenerational Effects and Mechanisms of Environmental Chemical Exposure

Time: 16:30 - 18:00

Mina Ha - Effects on children's neurodevelopment for pre- and postnatal exposure to lead, mercury, cadmium, and phthalate, considering sex difference in MOCEH study

Prof Mina Ha
Department of Preventive Medicine
College of Medicine Dankook University

Objectives: The Mothers and Children's Environmental Health study (MOCEH) is a multi-centric prospective birth cohort study investigating effects of various environmental pollutants on birth outcomes, growth and development, health, and disease of children. In this study, we report neurodevelopment outcomes affected by the heavy metals and phthalate exposure from the MOCEH study.

Methods: From 2006 to 2010 in South Korea, 1,751 pregnant women in their first trimester were recruited at 3 centers. The children were followed from birth up to 6 years. We used the information on neurodevelopment of children obtained by using the Bayley Scales of Infant Development II for infants and toddlers (BSID) up to 3 years of age, Wechsler Preschool and Primary Scale of Intelligence (WPPSI-R), revised edition at 5 years, the Korea Child Behavior Checklist (K-CBCL) and Social Responsiveness Scale (SRS) at 4, 5, and 6 years. Measured concentrations of lead, mercury, cadmium, manganese, and phthalate metabolites in prenatal maternal, cord and postnatal children's biospecimen were used.

Results: The results show the adverse effects of prenatal and postnatal exposure to lead, mercury, cadmium, and phthalates on children's cognitive and neurobehavioral development. We found a tendency that boys showed a stronger adverse effect for prenatal exposure while girls for postnatal exposure.

Conclusions: The collective results from MOCEH study provide scientific evidence that prenatal and postnatal heavy metals and phthalates exposure have an adverse effect on cognitive and neurobehavioral development of children, with a different critical exposure time by children's sex.

Shoji Nakayama - Bridging exposure to health effects

Shoji F. Nakayama, MD, PhD.
Deputy Director
Japan Environment and Children's Study Programme Office
National Institute for Environmental Studies

Historically, environmental epidemiology has placed its focus on impacts of air pollution on human health since it is relatively easy to obtain exposure data. On the other hand, human biomonitoring technique has developed rapidly in the past decade, enabling us to measure trace levels of multiple chemicals in our body system. Many epidemiologic studies now use human biomonitoring technique to examine the relationship between internal doses of chemicals and human health. It is considered that biomonitoring results better represent the internal dose of chemicals and are more precise measures for their impacts. However, one should be aware that biomarker concentrations are merely surrogates of exposure. In order to elucidate effects and mechanisms of chemical exposure, it is essential to connect dots from exposure to biomarker concentration to internal dose to effect markers to a health phenotype. Genetic and epigenetic interactions are also important to disentangle the mechanism. In the presentation, the current status of the research in this field and research gaps will be discussed.

Yufeng Qin - Prenatal DEHP exposure induces metabolic adaptation and obesity

Prof Yufeng Qin
School of Public Health
Nanjing Medical University

Di-(2-ethylhexyl)-phthalate (DEHP) is a ubiquitous environmental pollutant and is widely used in industrial plastics. However, the long-term health implications of prenatal exposure to DEHP remains unclear. We set out to determine whether prenatal DEHP exposure can induce metabolic syndrome in offspring and investigate the underlying mechanisms. A mouse model of prenatal DEHP exposure was established to evaluate the long-term metabolic disturbance in offspring. The mice were profiled for the hepatic metabolome, transcriptome and gut microbiota to determine the underlying mechanisms. Thiamine supplementation was administered to offspring to investigate the role of thiamine in ameliorating metabolic syndrome. Prenatal exposure to DEHP resulted in metabolic syndrome, including abnormal adipogenesis, energy expenditure and glucose metabolism, along with dysbiosis of the gut microbiome, in male offspring. Notably, hepatic thiamine metabolism was disrupted in these offspring due to the dysregulation of thiamine transport enzymes, which caused abnormal glucose metabolism. Prenatal DEHP exposure caused life-long metabolic consequences in a sex-dependent manner, and these consequences were attenuated by thiamine supplementation in offspring. Our findings suggest DEHP exposure during early life stages is a potential risk factor for later obesity and metabolic syndrome.

Binafsha Syed - Effects of Automobile pollution on apparently healthy population

Prof Binafsha Manzoor Syed, PhD
Liaquat University of Medical & Health Sciences

Automobile pollution is a global health issue results from vehicle exhaust released in the air. Major pollutants include PM2.5, PM10, CO, CO2, NOx, Sox commonly found in the pollutant air. Exposure to these toxins increases the rate of respiratory, ocular and dermatological problems. When human body gets exposed to these particles systemic inflammatory response is triggered. Chronic activation of inflammatory response raises the risk of other diseases as well. Recently we have conducted a study on detrimental effects of automobile fume on human health. The study was conducted in Hyderabad, Pakistan. Two groups of apparently healthy volunteers were included: 1. low exposure to automobile fumes, 2: high exposure to automobile fume. The air pollution was also measured in different areas of the town. The results showed a significant rise in inflammatory markers: Tumour Necrotic Factor α and β, C-Reactive Protein, Neutrophils and Eosinophils in high exposure population. There was a significant change in the lung function capacity.

The study concludes that the prolong exposure to automobile fumes triggers subclinical inflammatory response. Further detrimental effects of the prolong triggered inflammation needs to be explored.

Auditorium 2

ISES Symposium: Changing Environment, Metabolome, Microbiome and Health

Time: 11:00 - 12:30

Antoine Snijders - Systems biology and translational approaches to detemine environmental health effects

Antoine Snijders
Senior scientist
Lawrence Berkeley National Laboratory

Our research goals are to understand the complex interactions among genetic background, environmental exposures and the microbiome in determining disease risk. We pursue studies to gain insight into these interactions using mouse population-based cohorts and human epidemiologic studies. Precision medicine is an emerging approach for disease treatment and prevention that takes into account individual variability in environment, lifestyle and genes for each person. Genetic susceptibility is a major component that contributes to the variability in disease susceptibility. Thus, identifying the genes involved in susceptibility to disease risk may have potential utility in developing novel personalized medicines, lead to greater understanding of the biological pathways involved in disease development, and elucidate how environmental factors exert their effects in combination with genetic variants and the gut microbiome. This comprehensive systems biology approach will likely identify specific genes or pathways and microbial clades that are differentially controlled between individuals, and contribute to human variation in susceptibility to environment factor-induced disease. Our laboratory exploits the power of mouse genetics using Collaborative Cross (CC) mice, together with human cohort studies to determine the influence of individual variations in disease susceptibility.

Yuming Guo - Estimating global daily concentrations of PM2.5 and its health burden

Prof Yuming Guo
Monash University

Background: Few studies provide the global perspective on daily exposure to PM2.5. We aimed to estimate global daily PM2.5 exposure and its distribution of population exposure at high spatial resolution from 2014 to 2019.

Methods: We implemented a machine learning model based on observed daily PM2.5 concentrations from 8,357 monitoring stations in 77 countries, combined with the chemical transport models (CTM) simulations, satellite-based data, and metrological and land cover information to estimate global daily PM2.5 concentration at 0.1°×0.1° during 2014-2019. We also illustrated global distribution of the annual and daily PM2.5 exposure at the new WHO Global Air Quality Guidelines (AQGs) levels and calculated mortality burden due to exposure to daily PM2.5.

Results: Our machine learning model achieved the state-of-the-art performance with cross validation (CV) R2 of 0.89 and root mean square error (RMSE) of 10.69 μg/m3, with larger variations in Asia and Africa. The global population-weighted annual average PM2.5 was 30.8 μg/m3 (95% prediction interval, PI: 6.8μg/m3 to 137.0 μg/m3). There were only 1.32% of the global land area and 0.05% of the world population exposed to annual average PM2.5 below the WHO AQG annual guideline value (5 μg/m3) in 2019. For the global daily PM2.5 exposure, approximately 75% of the world's population and an average of 25% of the population in high income countries were exposed to daily average PM2.5 above the new WHO AQG daily guideline value (15 μg/m3) in 2019. About 1.3 million deaths were attributable due to exposure to daily PM2.5 every year.

Conclusion: Our global high-resolution daily PM2.5 estimates, for the first time, provide a global landscape and perspective on the unequal spatiotemporal distribution in PM2.5 exposure from 2014 to 2019, which is of significance for assessing the short-term health impacts of PM2.5, especially for areas where monitoring station data are not available.

Ru Yan - Host UDP-glucuronosyltransferases (UGTs) - gut microbial β-glucuronidases (GUSs) axis in metabolic homeostasis and drug exposure

Prof Ru Yan
State Key Laboratory of Quality Research in Chinese Medicine
Institute of Chinese Medical Science
University of Macau and Zhuhai UM Science & Technology Research Institute

As a paradigm of host-microbial metabolic symbiosis, the host UDP-glucuronosyltransferases (UGTs)-microbial β-glucuronidases (GUSs) axis plays an essential role in metabolic homeostasis by conjugating/deconjugating numerous biologically important endogenous molecules, such as bilirubin, estrogens, dopamine, etc. The coordinated efforts also affect the systemic exposures of many xenobiotics including western medicines and herbal/dietary components through interfering with their enterohepatic circulation. Gut dysbiosis has been implicated in a wide range of diseases. The structural shifts of gut microbiota not only change GUSs distribution and activity but also modulate UGTs expression via direct/indirect mechanisms. However, the roles of the UGTs-GUSs axis in disease progression and medication therapy have been scarcely addressed. This talk will feature the roles of UGTs-GUSs axis in disposition and efficacy of some herbal medicines, the glucuronide-conjugated metabolome and the alterations in responses to herbal interventions, in a colitis animal model. Gut microbial GUSs-mediated reactivation of the active metabolite SN-38, a DNA topoisomerase inhibitor, is believed to be an important player in severe diarrhea in CRC patients receiving irinotecan therapy. In this talk, the role of gut microbial GUSs in irinotecan-induced diarrhea will also be discussed on basis of the results of metabotypeing of CRC patients and a fecal microbiota transplantation study in mice. [Supported by the Science and Technology Development Fund of Macao (FDCT0098/2019/A2, 0091/2021/A2), Guangdong Natural Science Fund (2019A1515012195) and University of Macau (MYRG2018-00091-ICMS)]

Wei Jie Seow - Association between PM2.5 and nasal microbiome among occupational cooks in Singapore

Asst Prof Seow Wei Jie
Saw Swee Hock School of Public Health and Department of Medicine
Yong Loo Lin School of Medicine
National University of Singapore and National University Health System

Cooking fumes contain small particulate matter (PM2.5) which have been shown to be detrimental to respiratory health and associated with microbiota perturbations. However, studies on nasal microbiome are lacking.

A total of 20 occupational cooks (exposed) and 20 non-cooks (unexposed) in Singapore were recruited from 2019 to 2021. Information on the participants' sociodemographic and lifestyle factors was collected using questionnaires. PM2.5 concentrations were measured using portable real-time sensors. Bacterial 16S ribosomal ribonucleic acid (rRNA) was extracted from nasal swabs and sequenced. Comparison of alpha- and beta-diversity between the two groups was performed.

The exposed group had a significantly higher concentration of PM2.5 (p-value<0.01). In general, the nasal microbiome of cooks was less diverse and had higher species richness as compared to non-cooks, although not statistically significant. Beta diversity of the nasal microbiome was significantly different between the two groups.

Significant nasal microbiome differences were identified between the exposed and unexposed groups. Further studies are warranted to determine if these differences are attributable to prolonged occupational exposure to cooking fumes.

Minjian Chen - Application of exposome and metabolome analysis to the study of reproductive and developmental toxicities

Assoc Prof Minjian Chen
School of Public Health, Nanjing Medical University

Reproductive and developmental toxicants threaten human health, and the assessment of the exposure to a broad range of exogenous and endogenous chemicals is intriguing to provide an overall understanding of key reproductive and developmental toxicants and underlying mechanisms. We established methods for environmental chemical exposome and metabolome analysis by using chromatography tandem mass spectrometry and inductively coupled plasma mass spectrometry. Based on the human population study with a large sample size, we found a series of key reproductive and developmental toxicants by using exposome analysis. We further revealed the molecular mechanisms underlying reproductive and developmental toxicities by integrating the information of exposome and metabolome. Our study provides a new perspective on the key reproductive and developmental toxicants and metabolite-mediated mechanisms.

Exposome and Health

Time: 13:00 - 14:30

Thomas Astell-Burt - Have we reached peak-greenness? Green space and health research in the “big data” era

Prof Thomas Astell-Burt
Professor of Population Health and Environmental Data Science
University of Wollongong

Decades of research indicates green space supports various aspects of mental, physical and social health. Ethnographic studies indicate a vast complexity in the relationships between green space and health being contingent upon social, cultural, economic and climatic contexts. However, such complexity is insufficiently reflected in corresponding epidemiological studies, which are replete with (mostly cross-sectional) analyses utilising the normalised difference vegetation index (NDVI) to define so-called “greenness”. I argue that further accumulation of NDVI-based evidence has limited use-value to those with the power to drive positive change in urban planning and policies that affect green space provision and population health. We, as an international community of environmental epidemiologists, need to move on from studies capable only of concluding “more green space could be good for health”. We need to enrich our studies with robust data suited to well-defined exposures and, where possible, to experimental manipulation for enabling innovative randomised efficacy, effectiveness and implementation trials that advance understandings of green space and health and drive equitable societal change.

Yun-Chul Hong - Pre- and postnatal exposures to chemicals and greenness, and children's health

Prof Yun-Chul Hong
Institute of Environmental Medicine
Seoul National University Medical Research Center

Humans are exposed to various chemicals during their lifetime; however, evidence of health effects of such exposures in critical time windows is still insufficient. We aimed to elucidate the associations of chemical exposures during prenatal and postnatal time points with children's health in a prospective cohort study.

Prenatal and postnatal exposures to chemicals including BPA, F, S, pyrethroids, and heavy metals as well as greenness were quantified in pregnant women and their children who participated in the Environment and Development Cohort study. Children's neurobehavioral traits and IQ scores were assessed using various statistical models.

Both prenatal and early-childhood exposure to 3-PBA were found to be associated with ADHD symptoms. Pyrethroid exposures during pregnancy, and at ages 2 to 6 were found to be susceptible periods for neurotoxicity at ages 6 and 8. Bisphenols A, F, S were associated with ADHD symptoms at age 6. Multi-pollutant mixtures of prenatal and postnatal exposures to four metals affected child IQ at 6 years of age. We also found that 6-year-old children tended to score higher on total IQ if they were exposed to built greenness during prenatal period.

We found that children's health were affected by the various exposures at prenatal and postnatal periods The results provide further evidence of the health benefits of public health for children and pregnant women. Additional studies are warranted to confirm these associations and to control the exposure to different chemicals during pregnancy and preschool childhood.

Shu-Li Julie Wang - Exposome and health to encompass endocrine disruptors and maternal and child health

Shu-Li Julie Wang
National Institute of Environmental Health Sciences
National Health Research Institutes

Environmental Endocrine Disrupting Chemicals (EEDCs) are ubiquitous in daily lives. EEDCs have inorganic chemicals such as inorganic arsenic, cadmium, lead, and methyl-mercury. More EDCs belong to organic including persistent organic pollutants (POPs, including halogenated compounds of dioxins, polychlorinated biphenyls, perfluoroalkyl substances) and non-persistent ones (i.e., phthalates, bisphenols, parabens). These chemicals exist widely in food, particularly for animal sources for POPS and personal care products for phthalates and parabens, etc.; they may bind to various nuclear receptors of estrogen, androgen, thyroid, and peroxisome proliferator-activated receptor (PPAR) and thereby result in endocrine disruption, and affect immune and neurological health also.

Many EDCs chemicals can easily cross the placenta and even brain barriers and affect the early days of babies' epigenetic processes in utero. The fetal program may last for long and pose chronic diseases later in life, for example, allergic and infectious diseases, infertility, cardiovascular diseases, and cancers. The epigenetic changes were approved to be trans-generational in animal models. Nowadays, sciences propose the exposome concepts to obtain a complete picture of essential exposures, including EDCs, the so-called exposome, utilizing big data analysis techniques (i.e., machine learning). Exposome research appeared to be especially beneficial and crucial for the maternal and children populations. We may characterize well the critical risk factors for preventing high prevalent complex diseases and promoting health.

Oral abstract presentation: Machine learning and advanced techniques in exposure modelling

Time: 14:30 - 16:00

Yu-Ling Chen - Model development for NOx prediction with high spatiotemporal resolution using ensemble learning methods

Ms Yu-Ling Chen
Department of Geomatics
National Cheng Kung University

Using machine learning methods to model the concentration of nitrogen oxides (NOx) is widespread. However, few studies have concurrently developed NOx prediction models at various exposure windows such as daily, daytime, and nighttime exposures. This study aimed to develop fine spatiotemporal resolution (hourly-based exposed levels with 50-m * 50-m grid size) prediction models for estimating long-term NOx concentrations variations at different exposure windows in Taiwan by using an ensemble learning approach.

NOx observations from 1994 to 2020 were obtained as the dependent variable. Several spatial databases were used to extract the predictor variables for model development such as land-use inventory, landmark dataset, digital road network, industrial development bureau open dataset, spectrum-based vegetation index, air pollution database, and meteorological database. The model development procedures include three stages: (1) using a hybrid kriging/land-use regression (LUR) to identify important predictor variables; (2) model fitting based on the selected predictor variables coupled with five machine learning algorithms including: random forest, extreme gradient boosting, gradient boosting, LightBoost, and Catboost; (3) finalizing the ensemble learning model by using the predictions obtained from the top-three performed algorithms as predictors. Data splitting, 10-fold cross-validation, and external data verification were used to confirm the performance of the models.

Several common factors were selected in the developed models regardless the exposure windows, such as manufacturing within a 4000-m circular buffer, a temple within a 500-m circular buffer, and major road density within a 50-m circular buffer.

R2 of the finalized ensemble learning models was 0.96, 0.96, and 0.98 for daily, daytime, and nighttime exposure model, respectively. The robustness of the explanatory capability of the developed models was confirmed by the model validation tests.

This study demonstrates the values of the proposed ensemble learning approach in accurately estimating NOx concentration variations for daytime, nighttime, and daily

Sheng Yuan Chin - Explaining the prolonged half-life of perfluorooctanesulfonic acid in humans using a mechanistic physiologically-based toxicokinetic model

Mr Sheng Yuan Chin
Agency for Science, Technology and Research (A*STAR)

Perfluorooctanesulfonic acid (PFOS), an environmental toxicant, is found ubiquitously in consumer products and industrial manufacturing. PFOS is highly persistent, both biologically and environmentally due to its resistance to metabolic degradation, and long-term exposure is associated with adverse effects such as high cholesterol, thyroid disorders, cancers and reproductive diseases. The half-life of PFOS is estimated to be 3-5 years in humans; however, this has not been confirmed in human toxicokinetic studies, and the mechanisms underlying its in vivo persistence remain unclear. To address these gaps, we constructed a bottom-up, physiologically-based toxicokinetic (PBTK) model to understand the disposition mechanism of PFOS, predict its half-life and establish tissue concentrations. As PFOS is metabolically inert, its excretion is expected to be controlled by xenobiotic transporters in the kidney and liver. We generated an extensive panel of in vitro transporter kinetic data that was used to parameterize our in silico model without relying on extrapolations from animal data. Our simulations successfully recapitulated the years-long half-life of PFOS. Sensitivity analyses indicated renal clearance as the major elimination pathway, with extensive tubular reabsorption (which limits its urinary excretion) as the key driver of in vivo persistence. Importantly, our model can predict the in vivo PFOS tissue concentrations to assess its toxicological effect in various vital organs. Furthermore, by modifying the underlying physiology of our model, it can be applied to simulate toxicokinetic profiles in vulnerable and clinically inaccessible populations. Finally, the involvement of hepatic and renal transporters in PFOS excretion, which are also responsible for transporting endogenous substrates such as uric acid or bile acids may also explain epidemiological associations between serum levels of PFOS and these metabolites. In conclusion, we built the first bottom-up PBTK model to explain the prolonged half-life of PFOS which can be used to evaluate organ toxicity and epidemiological observations.

Tien-Wei Lin - Integration of Multiple Land-use Regression-based Machine Learning Models to establish a Mixed Spatial Prediction model for estimating Atmospheric Dioxin Concentration Variations in Taiwan

Mr Tien-Wei Lin
National Cheng Kung University
Department of Geomatics

Air pollution is closely related to human health. Dioxin, as the most toxic artificial chemical known so far, could also be transmitted through the atmosphere. However, there is currently a lack of relevant research on the spatiotemporal variability of atmospheric dioxin in Taiwan. Therefore, the objective of this study is to estimate the daily concentration variations of atmospheric dioxin in Taiwan during 2006 to 2016 based on a mixed spatial prediction model.

Atmospheric dioxin observations from 34 monitoring sites during 2006 to 2016 were extracted from the governmental open data platform. Important land-use/land cover related predictor variables were identified based on a stepwise variable selection in the land-use regression procedure. These selected predictors were then applied to fit the models by using several machine learning algorithms.

Dioxin concentrations estimated from the best three performed algorithms were then used as predictors again, to finalize the mixed spatial prediction model for estimating atmospheric dioxin concentration variations in Taiwan.

Models developed using an independent machine learning algorithm have moderate to high explanatory ability with model R-squared varies from 0.61 to 0.79. The predictive accuracy of the mixed spatial prediction model is even higher, and it's model R-squared increased up to 0.85. The mixed spatial prediction model proposed by this study is capable to estimate the daily concentration gradient map of atmospheric dioxin with a 50 meter * 50 meter grid resolution during 2006 to 2016.

This study demonstrates the value of the proposed mixed spatial prediction model approach in estimating atmospheric dioxin levels with a high explanatory accuracy.

Steve H.L. Yim - Development of new technologies for predicting multiple air pollutants with ultra-high spatial and temporal resolutions for detailed exposure and health assessments

Dr Steve H.L. Yim
Nanyang Technological University

Our recently global research proves the strong correlation between black carbon and lung adenocarcinoma cancer, and the varying effects of particulate matter (PM) components among countries, pinpointing the need to study health effects of air pollutions in details. However, the existing prediction technologies [i.e. using measurements at the nearest sites or land-use regression (LUR) modelling for annual-mean of a single pollutant] cannot support detailed exposure and health assessments. This project develops new technologies to predict multiple air pollutants with ultra-high spatiotemporal resolutions. We develop new satellite-retrieval technology to retrieve PM2.5 with 30m spatial resolution, and also develop LUR with machine learning to predict hourly and 500m-spatial-resolution nitrogen dioxide (NO2), PM with its components and ozone (O3). We apply the technologies in multiple cities to apportion source contributions, to evaluate the toxicity of PM components, and to quantify the resultant morbidity and mortality. Roadside measurement evaluation proves the promising capability (R2=0.79-0.98) of our satellite-retrieval technology, which is then used to analyze roadside pollution in 11 cities in Greater Bay Area of China. We compare our LUR model for Taipei with measurements, showing R2>0.72 for PM, NO2 and O3. With the advanced LUR modelling, we predict NO2 and PM2.5 in Seoul and estimate 15,000 premature mortalities in Seoul caused by air pollution every year. Our Hong Kong (HK) study estimates the toxicity of 11 PM10 components and finds PM10 concentration in HK is lower than its air quality standard but the PM10 toxicity level is higher than the safe level, indicating the high health risk of PM10 in HK. This study provides a powerful tool for detailed exposure and health assessments, supporting population health and urban sustainability. The technologies are currently integrated with exposure modelling to conduct detailed exposure assessment and to evaluate the effect of climate change on air pollutant exposure.

Chang Wei Kang - Understanding and Quantifying Environmental Transmission Risk of COVID-19

Dr Chang Wei Kang
Institute of High Performance Computing (IHPC)

The transmission of respiratory droplets/aerosols involves competing effects from drag, inertia, gravity and evaporation. It is significantly affected by complex flow phenomena including turbulent jets, flow-induced dispersion, sedimentation of droplet/aerosol and droplet evaporation and deposition.

The dual use of Computational Fluid Dynamics (CFD) simulations and surrogate aerosol experiments are proposed in this work. CFD-based framework incorporates expulsion force of fluid volume, droplet size distribution, evaporation and viral load to provide accurate insight and visualization of droplet/aerosol dynamics and spread. A computer-controlled aerosol generator and IoT-based particle sensors are used to measure the dispersion of a surrogate aerosol in related experiments. This complementary use of numerical and experimental methods enhances confidence in results obtained. Subsequently, results from CFD and experiments are converted into an easily interpretable and intuitive 3-tiered risk assessment scale for quantifying and assessing risk at different locations for various scenarios.

The proposed methodology has been widely applied to study of risk levels in different real-world built and transportation environments. In this work, the study of risks due to respiratory droplets/aerosols within a double-decker air-conditioned bus is presented. The placement of the air-conditioning return at the back of the bus causes significant airflow towards the rear with important ramifications on transmission risk. While larger droplets are dominated by gravitational and inertial effects and fall relatively near the cougher in the direction of the cough, smaller droplets are carried by this airflow towards the back of the bus. In the absence of mask, due to the return duct at the back of the bus, there is medium risk to the passengers sitting right behind the infected cougher. Passengers seated to the side of the coughing individual also experience slightly higher risk of exposure. Thus, the proposed methodology can enhance our understanding of the relative risk across scenarios and dominant factors.

Climate, air pollution, and health: Integration of Current Understanding and Future Perspective in India

Time: 16:30 - 18:00

Environmental factors such as extreme temperature and air pollution are associated with adverse health outcomes such as respiratory and cardiovascular morbidity and mortalities, however, there is a lack of knowledge on how environmental factors could be responsible for several other health outcomes such as premature skin ageing and mental health. It also remains unclear how temperature and air pollutants (PM, NO2, O3) interact with each other to contribute collectively to health outcomes.

Importantly, most of the epidemiological evidence is based on findings from developed economies, and the contribution from developing and underdeveloped countries remains low. Moreover, the populations among these countries are exposed to extremely high temperatures and air pollution, and climate change may worsen the condition further. Epidemiological research-based evidence in India is comparatively at a younger stage despite the fact that India stands at 7th position in the world climate risk Index and three of its cities come under the list of top 10 most polluted cities in the world. Therefore, it is imperative to encourage the research-based evidence from developing economies for a better understanding of the climate-air pollution-health nexus so that a consolidated mitigation approach could be constructed to combat the issues.

This symposium aims to present research-based evidence on the association between climate parameters, air pollution, and different health outcomes with a focus on India. The talks will enable our understanding of how the association might change in countries with very high extreme temperatures and high pollution load and how the population acclimatization to such climate and their socioeconomic structure could influence the association as well. The topic of this symposium is especially important for the translation of the current research results into decision-making and policy concerning country-specific public health measures, climate adaptation and mitigation, air pollution reduction, and health promotion.

Sagnik Dey - Ambient air pollution and health impacts in India: Moving beyond PM2.5 mass

Dr Sagnik Dey
Centre for Atmospheric Sciences
Indian Institute of Technology (IIT) Delhi

The health burden (attributable to air pollution) estimates under the Global Burden of Disease (GBD) Study revealed that the rising trend of ambient PM2.5 has been negating the benefit of declining household PM2.5 exposure. While the GBD study has established a framework to assess the health impacts of air pollution (not just in India, but globally), it assumes uniform toxicity of PM2.5 species. In this symposium, I will discuss the differential impacts of PM2.5 species on maternal and child health outcomes in India using India-specific health and exposure data. The participants of the symposium will be benefited to know about the recent findings of the study that shows relatively higher health impacts of exposure to BC and secondary particulate (nitrate/sulphate) compared to dust or OC across multiple health outcomes. Furthermore, we linked the species to sectoral emissions to prioritize sectoral interventions for maximum health benefits. In this symposium, we will demonstrate that we need to move beyond PM2.5 mass and call for systematic studies to understand the biological pathways attributable to sources, to better guide policymakers in clean air action plan implementation.

Vijendra Ingole - Local mortality impacts due to current ambient temperature and future air pollution in the urban and rural setting of Pune, India

Dr Vijendra Ingole
Geo-Health Group
Computer, Electrical, and Mathematical Sciences and Engineering Division
King Abdullah University of Science and Technology (KAUST)

India is highly vulnerable to climate change and is projected to experience some of the highest increases in average annual temperatures throughout the century. Exposure to high and low ambient temperatures is associated with morbidity and mortality across the globe. Most of these studies assessing the effects of non-optimum temperatures on health have been conducted in the developed world, whereas in India, the limited evidence on ambient temperature and health risks. Through this symposium, I will highlight the short-term association between temperatures and mortality in urban Pune, India. The participants of the symposium will be benefited to learn about the recent quantification of the local health impacts due to fine particles (PM2.5) under the governance arrangements embedded in the Shared Socioeconomic Pathways (SSPs1-5) under two greenhouse gas concentration scenarios (Representative Concentration Pathways (RCPs) 2.6 and 8.5) in local populations of rural Pune India.

Nidhi Singh - Ambient temperature and skin aging: A cross-sectional evidence from three metropolitan cities of India

Dr Nidhi Singh
IUF-Leibniz Institute of Environmental Medicine

Skin aging is driven to a large extent by environmental factors such as temperature, solar radiation, humidity, and air pollution. A growing body of literature supported a link between long-term exposure to air pollution (PM, NO2, O3, soot ) and extrinsic (environmentally induced) skin aging (pigment spots, coarse wrinkles) in elderly Caucasian and Chinese women. However, it is currently not known if the increasing ambient temperature (AT) could contribute to skin aging and/or if it modifies the air pollution-induced skin aging. This talk aims to discuss the role of AT in premature skin aging analyzed using an ordinal multiple logistic regression model in a cross-sectional study conducted in women above 20 years of age in three metropolitan Indian cities; Delhi, Mumbai, and Bangalore. The talk will also aim at discussing the role of air pollution, such as PM2.5 and NO2 in influencing the association between AT and skin aging. Further, the role of individual-level characteristics in influencing the association will be discussed. Lastly, the talk aims to advocate that long-term exposure to high AT may contribute to skin aging and that the effect might increase further in combination with high air pollution.

Akila Muthalagu - Potential health impacts of indoor air pollution caused by biofuel smoke

Ms Akila Muthalagu
Department of Civil Engineering
IIT Hyderabad

Inhalation of smoke emitted by biofuels used for daily cooking in developing countries might cause deleterious health effects. This talk aims to discuss the study conducted over fifteen villages to assess the trend of different fuel types. The talk will show the contribution of different biofuels used in Indian villages and how the culture of use of Liquefied petroleum gas (LPG) has been replacing the convention biofuels that would certainly add to the health benefits. The talk will discuss the dilemma on the use of clean fuel as the majority of the people prefer to use the traditional stove for time-consuming cooking activities and also because of the high cost of the LPG. In the symposium, we will also show the PM concentration measured inside such houses. The talk will highlight the issue of biomass burning as a potential source of indoor air pollution for several homes, thus eliminating biomass usage in one home might improve the air quality in several houses in a community.

Prince Vijay - Long-term air pollution exposure assessment in a cohort of adult women in metropolitan cities in India

Prince Vijay
Environmental Science and Engineering
IIT Bombay

The high population density and increase in associated motorized road transport demand are some of the major causes of increasing air pollution in most urban areas in addition to other sources such as traffic-induced road dust re-suspension, wind-blown dust, construction activities, and biomass burning, etc. These factors together with years of exposure to air pollution put a large proportion of the population at risk of adverse long-term health effects of air pollution. The talk focuses on the assessment of the long-term air pollution exposures namely NO2 and PM2.5 in three metropolitan cities in India, namely Mumbai, Bangalore, and Delhi to examine their effect on human health. Spatial modeling techniques including land-use regression (LUR) models are developed to assess the residential outdoor exposures of the cohort participants. Additionally, the talk also focuses on the aerosol properties and important chemical characteristics responsible for adverse health and climate effects. Lastly, the probable sources contributing to the particulate matter will be discussed which will serve as a piece of key information for decision-makers in designing effective air pollution control strategies in the urban areas.

Auditorium 3

Oral abstract presentation: Maternal and child health in Asia and Western Pacific - Lessons learnt from birth cohorts

Time: 11:00 - 12:30

Nathan Cohen - Exposure to Perfluoroalkyl Substances at Preconception in Association with Fertility Outcomes in Women from Singapore

Dr Nathan Cohen
Department of Environmental Medicine and Public Health
Icahn School of Medicine at Mount Sinai

Objectives: Exposure to perfluoroalkyl substances (PFAS) may affect fertility and fecundability, but human studies are scarce. We assessed the sociodemographic determinants of PFAS exposures, and the associations between preconception PFAS concentrations and the odds of pregnancy and live birth in women in Singapore.

Methods: In a case-control study nested within the Singapore Preconception Study of Long-Term Maternal and Child Outcomes, we measured PFAS in preconception serum from 382 women of reproductive age (328 who became pregnant and 54 who failed to conceive or miscarried within 12 months). Using logistic and weighted quantile sum (WQS) regression respectively, we assessed the associations between individual PFAS and the PFAS mixture with the odds of pregnancy or live birth adjusted for batch, maternal age, maternal education, maternal ethnicity, household income, and parity.

Results: Seven out of 15 measured PFAS were detected in ≥30% of women. PFOS median concentrations were higher among Chinese women compared to Indian women (2.5 [1.9, 3.4] vs. 1.6 [1.1, 2.2] ng/ml, respectively). PFOA median concentrations were higher in women with higher education (1.9 [1.4, 2.4] post-secondary vs. 1.3 [1.1, 1.6] in primary/secondary group). We found non-significant negative associations between higher PFAS mixture exposure and the odds of conception (WQS: OR [95% CI] per quartile increase=0.67 [0.44, 1.02]) and live birth (0.71 [0.47, 1.06]). The major contributors to the PFAS mixture associations were PFOA and PFOS. In individual PFAS analyses, we found somewhat stronger negative associations for PFOA with conception (OR [95% CI]=0.64 [0.39, 1.05]) and live birth (0.68 [0.42, 1.09]), compared to PFOS (0.69 [0.40, 1.19] for conception, and 0.73 [0.43, 1.23] for live birth) or other PFAS.

Conclusions: Among Singaporean women, we found evidence that higher PFAS mixture exposure may decrease the likelihood of becoming pregnant or delivering a live birth. These findings need further investigation in larger populations.

Jian Huang - Preconception circulating biomarkers and offspring Child Behaviour Checklist (CBCL) scores the S-PRESTO cohort

Dr Jian Huang
Agency for Science, Technology and Research (A*STAR)

Maternal micronutrients have been associated with offspring cognitive development. Though different micronutrients may act synergically, most studies assessed their effects separately. We aim to evaluate the effects of various pre-pregnancy micronutrients on child behavioural problems.

This study was conducted using a preconception, longitudinal cohort, Singapore Preconception Study of Long-Term Maternal and Child Outcomes. We used K-means clustering to identify micronutrient clusters. Levels of micronutrient clusters are indicated by the average standardised level of micronutrients in the corresponding cluster. Child behavioural problems at age 3 years was assessed by parent-reported Child Behavior Checklist (CBCL, N=220). A flexible variable selection and response modelling method, Bayesian kernel machine regression (BKMR), was used to simultaneously assess the effects of all micronutrient clusters on child behavioural problems. A total of 194 mother-child dyads had complete data on both micronutrient clusters and CBCL scores, among which 131 were included in the fully adjusted model. We also performed multiple imputation in a sensitivity analysis to impute missing data among participants with available CBCL assessment.

Five clusters were identified for 56 micronutrients. A non-linear relationship was observed for the Vitamin B6 and B1 cluster with pervasive developmental problems, with a posterior inclusion probability (PIP) greater than 0.8, adjusting for demographic, pregnancy-related covariates, and maternal mental health. PIP remained greater than 0.8 in the sensitivity analysis with multiple imputation and in stratified analysis among the participants with a below median level of Vitamin B6 and B1 cluster. Among those with an above median level of Vitamin B6 and B1 cluster, PIP was below 0.5.

Among those with lower level of Vitamin B6 and B1, a positive association between these micronutrients and pervasive developmental problems was observed. Further research to elucidate the reasons for this association.

Surabhi Shah - Prenatal BPA exposure and cognitive growth at five years in two birth cohorts

Dr Surabhi Shah
Department of Environmental Medicine
Ewha Womans University College of Medicine
Seoul, South Korea

Background: Bisphenol-A (BPA) has been recognized to cause developmental neurotoxicity. There have been studies of children's cognitive development in relation to mother's BPA exposure but the results remain inconsistent. In this study, we evaluated the effect of prenatal BPA exposure on cognitive performance in 5 years old children in two birth cohorts.

Methods: This study included data from 2 birth cohorts: i) The Korean Mothers and Children's Environmental Health study (MOCEH) (n =165) and ii) Chinese Laizhou Wan Birth Cohort (LWBC) (n = 295). Both the cohorts collected information about maternal BPA exposure during pregnancy and cognitive performance in children at age 5. Linear regression analysis was performed to compute mean differences and 95% confidence intervals in children's total, verbal, and performance cognition scores measured on Wechsler Preschool & Primary Scale of Intelligence (WPSSI) comparing prenatal BPA with adjustments for numerous potential confounding factors. Models were computed separately for each cohort and meta-analysis was conducted.

Results: No association was detected between prenatal BPA exposure and cognitive development at 5 years in both the cohorts. This pattern was seen across all cognitive dimensions, but the results were imprecise overall. Meta-analysis results show that BPA exposure reduced verbal IQ [-1.80 (-3.38, -0.23)] at 5 years after adjusting for mother's IQ.

Conclusion: Our results show that prenatal BPA exposure reduced verbal IQ in children at 5 years. Our results direct towards comparison of the similarities and differences of BPA population exposure characteristics, putting forward the intervention measures in accordance with different national condition.

Acknowledgement: We are thankful to all the participants in both the birth cohorts

Hsuan-Hui Su - Prenatal Fine Particulate Matter Exposure in Association with Global DNA Methylation and Children Health

Miss Hsuan-Hui Su
Institute of Environmental Health and Occupational Health Science
National Taiwan University College of Public Health

Fine particulate matter (PM2.5) exposure during gestation could result in adverse birth outcomes even adverse childhood health. To determine the sensitive time for fetal development, many studies investigated the exposure effects by trimester. More refined time window is required to estimate the exposure effects during the critical period of rapid growth and development. Global DNA methylation levels, as early markers of toxicity, may help answer the questions of PM2.5 exposure effects.

The study aimed to explore weekly gestational PM2.5 exposure effects in association with global DNA methylation and adverse birth outcomes.

Study participants living in Taipei metropolitan area were from Taiwan Birth Panel Study (TBPS), including 451 children born in 2003-2005. Cord blood LINE-1 and Alu methylation levels were measured by pyrosequencing to represent global methylation levels. Extreme gradient boosting (XGBoost) model fitting by PM2.5 measurements from air quality monitoring stations, meteorological, land use and time data were used to estimate daily PM2.5 concentration at residential address of participants and evaluating weekly mean. Linear or logistic regression model combined with distributed lag non-linear models were used to analyze the relationships between prenatal weekly PM2.5 exposure and adverse birth outcomes.

By using PM2.5 exposure at 25 μg/m3 as reference group, an increment of 10 μg/m3 of PM2.5 during the 8th to 25th gestational weeks was significantly associated with 21 to 71 grams decrease in birthweight. Significantly increased risk of preterm birth was link to the 6th to 11th gestational weeks exposure. Significantly decreased LINE-1 and Alu methylation levels were observed during the 9th to 25th weeks exposure.

The 6th to 25th gestational weeks were critical PM2.5 exposure periods for decreased birth weight and increased risk of preterm birth. During the susceptible windows, decreased LINE-1 and Alu methylation levels were significantly associated with PM2.5 as well.

Jonathan Huang - Maternal plasma folate concentrations and PFAS transplacental transfer ratios: evidence from two prospective cohort studies

Dr Jonathan Huang
Singapore Institute for Clinical Sciences

Per- and poly-fluoroalkyl substances (PFAS) cross the placenta and in utero exposures have been associated with numerous adverse offspring metabolic and neurodevelopmental outcomes. Modifiable determinants of fetal exposure are not well understood, though folate status may be implicated. We evaluated prospective associations between maternal mid-pregnancy plasma folate concentrations and delivery PFAS and transplacental transfer ratios (umbilical cord/maternal blood concentrations).

We studied 783 mother-offspring pairs from the Growing Up in Singapore Towards health Outcomes (GUSTO) population-based, longitudinal cohort with a semi-replication in 384 preconception women (S-PRESTO cohort). Plasma folate was assayed by standard clinical laboratory methods; 12-16 PFAS were quantified by LC-MS/MS; and transplacental transfer ratios were computed as log2(cord / maternal concentration). Associations were estimated by linear regression adjusted for: batch; FFQ-estimated total fat, protein, and whole grains; maternal GDM status, ethnicity, educational attainment, pre-pregnancy BMI, parity, and age at delivery; household smoking; and child sex.

Eight PFAS were detected in >90% of all GUSTO samples. Transplacental ratios ranged from 0.3 for PFOS to 1.6 for PFBS. Maternal plasma folate concentrations were associated with higher PFAS ratios (e.g. 0.6% higher PFBS ratio per 1 ng/mL plasma folate; [95% CI: 0.2%, 0.9%]; p = 0.001). Taken individually, plasma folate was generally associated with lower maternal and higher cord PFAS concentrations. In the semi-replication, maternal preconception folate was weakly associated with reduced PFAS (e.g. 7% lower PFOA-linear per doubling of plasma folate [-14.4%, 0.9%]).

Overall, we observed higher plasma folate in mid-pregnancy were associated with higher placental transfer ratios of PFASs at delivery. Maternal inverse associations were supported in preconception women. Clinical implications are difficult to assess because regulators of placental PFAS transfer remain poorly understood, including whether these association truly reflect transfer. More follow-up including mechanistic studies of placental transporters is needed.

Oral abstract presentation: Recent Issues on Environmental Risk Factors and Health in Asia and Western Pacific

Time: 13:00 - 14:30

Nicholas Osborne - Relationship between potentially inflammatory-based diseases anxiety and atopy in Australian children

Dr Nicholas Osborne
University of Queensland

New evidence is emerging that some mental health disease is related to inflammation. This could see individuals with multiple inflammatory diseases sharing pathological pathways. We will assess the relationship between anxiety and immune-related disease of atopic origin in a cohort of Australian children to examine if they are related in any way.

We examined the Longitudinal Study of Australian Children, a population representative survey of Australian children which has been running since 2003 and consists of nine waves of data. 10000 participants divided into baby and child cohorts (2x 5000). We analysed the remaining 3127 adolescents and 3037 young adults. A range of questionnaire data on risks and health have been used to identify health status and risk factors/confounders. Relationships were adjusted for a range of know potential confounders, including sex, BMI, socio-economic indexes for areas, state of residence and remoteness of the area.

Around one third to one quarter of participants had asthma (30.5%, 95%CI 28.9, 32.2) in 14-15-year-olds and in 18-19-year-olds (25.4%, 95%CI 23.8, 27.1). Anxiety was also prevalent in 14-15 years (9.3%, 95% CI 8.3, 10.5) and 18-19 years (16.3%, 95%CI 14.9, 17.8). In a cross-sectional design both baby and child cohort anxiety was associated with asthma diagnosis (aOR 1.6, 95%CI 1.2, 2.0) and (aOR 1.5, 95%CI 1.2, 1.9). Presence of anxiety increased the risk of other atopic-related diseases eczema and food allergy. There was a trend for more atopic disease in southern regions.

There is a relationship between anxiety and atopy in this Australian cohort, which may be bi-directional. A common pathological pathway for both diseases groups is possible. More solar exposure in more northerly states may be related to better immune health. Reducing risk factors that increase immune dysfunction may reduce these chronic diseases.

Nan Lin - PFAS Exposure and Association with Hypertension in Low-exposure Population

Dr Nan Lin
Shanghai Jiao Tong University

The pollution of per- and poly-fluoroalkyl substances (PFASs), emerging persistent organic pollutants, seriously affects the quality of ecological environment and threatens the health of people. They have been found to be endocrine disruptors, which may elevate blood pressure. The elderly population is a typical group exposed to PFASs and has high prevalence of hypertension, while their PFASs exposure characteristics and the association with hypertension are unclear. We collected 395 women (aged 50+) from Shanxi, China and analyzed 30 target PFASs in their whole blood. Amongst, 162 (41%) had hypertension. 10 PFASs had detection frequency over 80%. They were PFHxA, PFHpA, PFHxS, PFOA, PFHpS, PFNA, PFOS, PFDA, 9Cl-PF3ONS, and PFUdA. PFOS, PFOA and PFHxS had higher levels among 30 PFASs. The median and mean +/- standard deviation values were 1.59 ng/mL and 2.68 +/- 3.34 ng/mL for PFOS, 0.68 ng/mL and 0.85 +/- 0.55 ng/mL for PFOA, and 0.18 ng/mL and 0.32 +/- 0.40 ng/mL for PFHxS. What's more, 9Cl-PF3ONS, the main component of F-53B (a chromium mist inhibitor unique in China), had 100% of detection frequency, and the median and mean +/- standard deviation values were 0.16 ng/mL and 0.20 +/- 0.16 ng/mL. The elevated PFASs concentrations were significantly associated with higher age. And higher PFOS, PFUdA and 9Cl-PF3ONS was associated with more meat consumption, implying meat could be an exposure source. For the 10 PFASs with DFs over 80% except PFOS, higher concentrations were found in hypertension population (Mann-Whitney U test, p < 0.05). After adjusted for covariables (age, BMI, education, smoking, exercise, and meat), people with 9Cl-PF3ONS higher than median value had higher hypertension risk (OR = 1.63, 95% CI: 0.99 - 2.68). Our results suggested 9Cl-PF3ONS, a unique PFAS in China, may be a risk factor for hypertension in Chinese elderly people.

Xin Meng - Cardiovascular effects of reducing particulate matter with facemasks: A randomized, double-blind, crossover trial

Miss Xin Meng
Peking University

Objectives: Wearing facemasks is a common means of personal protection against airborne particulate matter in daily scenes and occupational places. The cardiovascular effects from the facemask wearing in the real world remain unconfirmed.

Methods: We conducted a randomized double-blind crossover trial in 52 healthy college students in Beijing, China. At baseline screening, systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse wave velocity (PWV), and augmentation index (AIx) were measured in the supine resting position. Participants were then randomly assigned to wear a real N95 facemask (with filter) or a sham one (without filter) and exposed outdoors for 2 hours. Blood pressure and arterial stiffness were measured at half, three and five hours after exposure. We used a mixed effects model to analyze the cardiovascular effects of facemask, and further stratified by PM2.5 levels (median: 75 μg/m3).

Results: The 2-hour PM2.5 concentrations ranged from 4.9 to 255 μg/m3. SBP, DBP, PWV and AIx all decreased first and then recovered, but decreased more in the group with sham facemasks. More interestingly, in the scenario when PM2.5≥75 μg/m3, the beneficial cardiovascular effects were more significant in the real facemask group than in the sham facemask group, e.g., PWV at 3 h after exposure decreased 0.55 m/s in the real facemask group and increased 0.03 m/s in the sham facemask group from the baseline (between-group difference P<0.05). In the comparing scenario when PM2.5<75 μg/m3, the cardiovascular effects of the real facemask group were not better than that of the sham facemask group.

Conclusions: Wearing facemasks is plausible to be protect against cardiovascular damage induced by particulate matter in heavily polluted environments. But it warns that wearing facemasks may have potential side effects.

Hao-Ting Chang - Is suicide ratio associated with greenness and green space structures in Taiwan? A longitudinal ecological study

Dr Hao-Ting Chang
Department of Geomatics
College of Engineering
National Cheng Kung University

Objectives: Since suicide rates remain high, prevention measure is one of the recent public health priorities in Taiwan. Multiple national population-based studies have revealed that green space exposure may have the potential to reduce the risk of suicide. Nevertheless, the correlation between suicide and normalized difference vegetation index (NDVI) and specific green space structures at the township scale remains unclarified. Hence, this study aims to comprehensively elaborate the specific association between greenness exposure (NDVI, greenness coverage ratio) and green space structures, and suicide ratio across townships in Taiwan.

Methods: We extracted the monthly suicide ratio of all townships in Taiwan from the Cause of Death Statistics, Health and Welfare Data Science Center, Department of Health and Welfare from 2000 to 2018. The demographic and social, socioeconomic, meteorological data, air pollution, overall greenness, and green space structure factors including mean patch area (area and edge), area-weighted mean fractal dimension index (shape), and proximity index (proximity) were sorted out. Finally, the generalized additive mixed model was utilized to analyze the association between green space exposure and suicide ratio.

Results: The relative risk (RR) [95% confidence interval (CI)] of NDVI, greenness coverage ratio, mean patch area, area-weighted mean fractal dimension index, and proximity index was 0.860 (0.811, 0.912), 0.998 (0.997, 0.999), 1.485 (1.056, 2.088), and 0.999 (0.999, 0.999), respectively. In other words, the greener the exposed green space, the larger the area, the closer the distance, and the simpler the shape might lower the suicide risk in Taiwan. Similar results were revealed in both sensitivity tests and subgroup analysis.

Conclusions: The results of this study propose the green space structures as a potential prevention strategy, which can be formulated in the related policies of the local government to reduce the high suicide ratio.

Natalia Borzino - Heat and air pollution degrade learning and human capital development: global evidence from OECD PISA exams 2000-2018

Dr Natalia Borzino
Singapore ETH Centre

We provide estimates of the causal effect of heat stress and air pollution on long-term learning and human capital accumulation using global data from the OECD PISA exams from 2000 to 2018. We created a database with the standardized scores for 59 countries with the maximum Wet Bulb Globe Temperature (WBGT) index as a measure of heat stress, and the mean annual concentrations of fine particulate matter less than 2.5 μm (PM2.5) as a measure for air pollution. Our results showed heat stress and low air quality significantly degrade short-term cognitive performance, driven by a long-term accumulative impact of both heat and air pollution. Indeed, a 1 degree C increase in the annual max WBGT and 1 ug/m3 increase in the annual PM2.5 decreases the scores by 4.7% and 2.8% of a standard deviation, respectively. These long-term effects were concentrated solely in the school months arriving to a negative impact on the scores by 6.3% of a standard deviation. Furthermore, the effect of a 1 degree C increase in the annual max WBGT on the standardized PISA scores exacerbates when it is combined with high unhealthy levels of PM2.5, decreasing the scores by up to 7.9% of a standard deviation. These findings provide evidence of the magnitude to which chronic exposures to both heat and air pollutants, evaluated separated and combined, can degrade learning, human capital development and ultimately, economic growth. Globally, climate change can unfairly penalize hotter regions and poorer countries and further exacerbate inequalities and compromise their human capital stock. Policy interventions aimed to mitigate the effect of heat and air pollution in cities, and particularly in school classrooms, could help protect children and adolescents against the harmful effects. Investments made in this sense may confer important economic benefits for those countries in the short and long term.

Late-breaking oral abstracts

Time: 14:30 - 16:00

Rekha Shanmugam - Workplace Welfare Facilities And Women's Health In Hot Working Environments - A Comparative Study Between Informal And Formal Indian Workplaces

Mrs Rekha Shanmugam
Sri Ramachandra Institute of Higher Education and Research

Background: With the increasing number of women forced to enter various occupations in developing nations to support the nation's economy, so does their exposure to numerous workplace hazards. Hot-working settings and insufficient welfare facilities are increasing health issues, requiring further research.

Objectives: This study aims to compare the impact of welfare facilities on women's health while working in informal and formal high heat work settings.

Methods: We conducted a cross-sectional study with 434 women workers in two informal sectors (agricultural and salt pan workplaces) with no workplace welfare facilities and two formal sectors (steel and commercial kitchen) with adequate welfare facilities, including work-rest regimens, water coolers, and adequate toilet facilities, between 2017 and 2019. We assessed Wet Bulb Globe Temperature (WBGT) and Urine Specific Gravity (USG) and gathered self-reported urino genital symptoms such as burning sensation, change in urine volume & color, and genital itching. The data analysis was done using Multivariate Logistic Regression models in SPSS version 16.0.

Results: Both the informal and formal sectors had high WBGT exposures, with average WBGTs of 30.1°C±1.3°C & 31.6°C±3.3°C, respectively. Even after controlling for potential confounders, women in informal sectors reported more dehydration symptoms than women in formal work sectors (69% vs. 23%). The risk of reporting dehydration was 7.5-fold higher among women in informal sectors (95 % CI: 3.5-14.9). Urogenital problems were reported at a significantly higher rate (AOR: 3.4; 95% CI: 2.1-5.4) among workers in informal sectors with no welfare facilities (80% vs 20%). The measured USG results are consistent with self-reported potential issues, with 61% and 40% in the informal and formal sectors, respectively (AOR:1.9; 95% CI: 1.1-3.1).

Conclusion: Dehydration and urogenital issues highlight worker wellbeing. The lack of welfare amenities exacerbates the informal sector's heat and physical labor risks. Poor women in informal settings face few workplace hazards.

Sun-Young Kim - Effectiveness of the Emergency Fine Dust Reduction Measures in traffic reduction in Seoul, Korea

Dr Sun-Young Kim
National Cancer Center

Background: Many countries have implemented regulatory actions to improve air quality over several years to decades particularly focusing on traffic reduction. Some previous studies reported the effectiveness of these long-term actions such as low emission zones and fuel refinement. Recently, a few efforts focused on short-term changes in air quality leveraging public communication given frequent high-concentration episodes. As an example, the Seoul city government in South Korea implemented the Emergency Fine Dust Reduction Measures (EFDRM) in 2018 where citizens are notified through public messages. The public messages also encourage the use of public transportation and/or participation in the odd-even traffic restriction system. However, few studies evaluated the effectiveness of short-term actions.

Objectives: We aimed to examine the changes in traffic counts on EFDRM-issued days from those on the days not issued after the EFDRM implementation compared to before the implementation.

Methods: We obtained publicly-available data for hourly traffic counts, PM2.5, and meteorology in Seoul for 2016-2019. Using generalized additive model, we estimated the differences in traffic counts between the days with and without the EFDRM as well as between pre- and post-implementation periods after adjusting for PM2.5 and meteorology. In addition, we compared these differences by rush and non-rush hours and by weekdays and weekends/holidays in order to examine the changes in travel behavior possibly derived by public awareness.

Results: The traffic counts on EFDRM days were significantly lower than on non-EFDRM days after the implementation, but consistent before the implementation. This decrease was also found on weekends/holidays and during weekday non-rush hours, but not during weekday rush hours.

Conclusions: Our findings of traffic reduction attributed to the EFDRM and different patterns depending on hours and days suggest the important role of public perception and voluntary participation in air quality improvement and provide the guidance to short-term air pollution interventions.

Sylvester D. Nyadanu - Maternal exposure to acute thermophysiological stress and spontaneous preterm birth: a space-time-stratified case-crossover analysis in Western Australia, 2000-2015

Mr Sylvester D. Nyadanu
Curtin School of Population Health
Curtin University

Background: Previous studies reported inconsistent associations between acute thermal stress and preterm birth (PTB) based on ambient temperature metrics instead of human thermophysiological metrics. This study aimed to examine the association between maternal thermophysiological stress as measured by a suitable contemporary bioclimatic index, Universal Thermal Climate Index (UTCI) and spontaneous PTB.

Methods: Daily records of 15,576 live, singleton spontaneous PTB between 1st January 2000 and 31st December 2015 were linked to daily mean UTCI across 4,504 small area units in Western Australia. We conducted a space-time-stratified case-crossover analysis with distributed lag nonlinear models and conditional quasi-Poisson regression. Time-invariant and time-varying confounders, seasonal and long-term trends, and spatial variations were controlled by design. Public holidays were also controlled.

Results: Relative to the median UTCI, representing no thermal stress, exposures to the 1st to 25th percentiles of UTCI showed no association while the 95th and 99th percentiles of UTCI associated positively with the risk of PTB during the days in the week of delivery. Relative to the median UTCI (13.8 °C), the heat stress exposure (99th percentile of UTCI, 31.2 °C) elevated the risk by 1% (RR= 1.01, 95% CI 1.01, 1.02) on the day of delivery and 5% (RR=1.05, 95% CI 1.04, 1.06) up to 6 days preceding delivery. Risk was higher among male infants, and infants born to unmarried mothers, young mothers, mothers that smoked during pregnancy, and non-Caucasians.

Conclusion: Maternal exposure to acute heat stress, but not cold stress elevated the risk of PTB in Western Australia. Heat-related public health interventions, including climate change policy and heat mitigation strategies such as improved heat-resilient housing, increase affordability and use of air conditioning, hydration, and decreased outdoor activities during heat stress episodes, particularly among higher-risk pregnant women may be helpful. Future related studies should consider human thermophysiological metrics such as UTCI.

I Gusti Ngurah Edi Putra - Does quality neighbourhood green space promote kindness among children? If yes, how? Evidence from Australia

Mr I Gusti Ngurah Edi Putra
Population Wellbeing and Environment Research Lab (PowerLab)
School of Health and Society, University of Wollongong

To understand whether quality green space is associated with prosocial behaviour and investigate the potential pathways.

This study involved 4,969 children with 10-year biennial follow-up data (2004-2014; aged 4-5 to 14-15 years), retrieved from the K-cohort of the Longitudinal Study of Australian Children. Green space quality was assessed based on caregiver reports on the availability of “good” parks, playgrounds, and play spaces in their neighbourhoods. Caregivers evaluated children's prosocial behaviour using a prosocial sub-scale from the Strengths and Difficulties Questionnaires (SDQ). Latent class analysis grouped children into different developmental trajectory clusters of exposure to green space quality in 10 years. Multilevel linear regression examined the confounders-adjusted association between green space quality (i.e., standard variable, trajectory classes) and prosocial behaviour. In addition, a range of candidate mediators across child physical activity, social interaction, health-related quality of life (HRQOL), mental health (i.e., internalising and externalising problems from SDQ), and caregiver psychological distress, were tested using causal mediation analysis.

Overall, quality green space was positively associated with prosocial behaviour. Findings from the latent class analysis showed six distinct trajectory classes of exposure to quality green space. Relative to exposure to low-quality green space over time, children whose caregiver perceptions of quality green space trended from good to very good (β=0.23; 95%CI=0.11, 0.35), from very good to good (β=0.31; 95%CI=0.20, 0.42), and were consistently in very good quality (β=0.35; 95%CI=0.23, 0.47) across childhood had greater prosocial behaviour. Findings from causal analysis indicate that child physical activity enjoyment, social interaction, HRQOL, and child and caregiver mental health might serve as pathways in which quality green space can influence prosocial behaviour.

Growing up in neighbourhoods with high-quality green space is important to support the development of prosocial behaviour among children, in which the improvement in health-related behaviours might serve as linking pathways.

Liang En Ian Wee - SARS-CoV-2 transmission in cohorted hospital cubicles and isolation areas: infrastructural features associated with onward transmission and environmental contamination

Dr Liang En Ian Wee
Singapore General Hospital

During the ongoing coronavirus disease 2019 (COVID-19) pandemic, hospital infrastructure has been modified to segregate suspected/known COVID-19 cases in purpose-built and converted isolation-areas; however onward transmission can still occur. We report features of the hospital environment associated with onward transmission of SARS-CoV-2 from previously unsuspected hospital-onset COVID-19 cases.

The study-period lasted 9-months (21st June 2021-21st March 2022) at a Singaporean tertiary hospital. Patients are mostly housed in 5-6-bedded cohorted-cubicles with shared-toilets; with beds six-feet apart. Rates of hospital-onset COVID-19 infection and onward-transmission amongst inpatients were monitored. Onward-transmission was ascertained through contact-tracing, epidemiological investigation and whole-genome-sequencing. Environmental sampling for SARS-CoV-2 was conducted over a 1-week period (28th July 2021-5th August 2021) in temporary isolation-areas. Factors associated with onward-transmission were identified through chi-square test and multivariate-logistic-regression.

Onward-transmission occurred in 21.2% (66/312) of hospital-onset COVID-19 cases. On multivariate-logistic-regression, admission to a cubicle/room without an en-suite toilet (adjusted odds-ratio, aOR=1.90, 95%CI=1.01-3.54, p=0.044), and being in a cohorted-cubicle versus a single-room (aOR=13.32, 95%CI=1.63-109.10, p=0.016) were all independently associated with higher odds of onward-transmission. Onward-transmission beyond immediately-adjacent beds occurred in the majority (63.6%, 42/66) and was independently associated with usage of the common-toilet by the index-case (OR=4.12, 95%CI=1.44-12.07, p=0.010). Being housed in the temporary container-ward (aOR=16.90, 95%CI=3.10-91.96, p<0.001) was independently associated with greater odds of detectable SARS-CoV-2 environmental contamination. Despite detectable environmental contamination, no evidence of nosocomial transmission was identified amongst HCWs working in isolation-areas, on whole-genome-sequencing and outbreak-investigation.

Features of the built-environment, such as absence of en-suite toilets and cohorted-cubicles, were significantly associated with onward transmission of SARS-CoV-2 in a hospital environment. While environmental contamination was detected in a temporary container isolation-ward, no nosocomial transmission occurred amongst HCWs working in these isolation-areas.

Oral abstract presentation: Air pollution and health (2)

Time: 16:30 - 18:00

Trang Nhung Nguyen Thi - Attributable mortality due to long-term exposure to PM2.5 in 11 provinces, Vietnam 2019

Dr Trang Nhung Nguyen Thi
Hanoi University of Public Health
Vietnam National of Children's Hospital

Objectives: This study aims at calculating the mortality attributed to PM2.5 concentration in 11 provinces of Northern Vietnam and Ho Chi Minh city in 2019 using Environmental Benefits Mapping and Analysis Program - Community Edition (BenMAP-CE) tools.

Methods: We applied the Global Exposure Mortality Model for Non-communicable diseases and Lower respiratory infection (GEMM NCD-LRI), the annual mean of ambient PM2.5, and population size to estimate the attributable deaths of people above 25 years old in Bac Ninh, Dien Bien, Ha Nam, Ha Noi, Hai Duong, Hai Phong, Ho Chi Minh City, Hung Yen, Ninh Binh, Thai Binh, and Thai Binh. We used the WHO Air Quality Guideline-AQG (5µg/m3) and Vietnam National Ambient Air Quality Standard-QCVN (25µg/m3) as our two counterfactual scenarios.

Results: The annual population-weighted mean concentration of PM2.5 in these provinces ranged from 15.22 µg/m³ in Dien Bien to 38.11 µg/m³ in Bac Ninh. In compliance with AQG scenario, the PM2.5 attributable death rate ranged from 63 cases per 100,000 (95%CI: 47-77) in Dien Bien province to 160 cases per 100,000 (95%CI: 122-194) in Thai Binh province. On the other hand, in compliance with QCVN, these numbers ranged from 10 cases per 100,000 (95%CI: 8-13) in Ho Chi Minh city to 41 per 100,000 (95%CI: 31-50) in Bac Ninh Province.

Conclusion: This study confirmed that a considerable proportion of premature deaths in Vietnam could be avoided if the Vietnam government took action to reduce air pollution.

Shaowei Wu - Ambient particulate air pollution, blood cell parameters, and effect modification by psychosocial stress

Prof Shaowei Wu
Xi'an Jiaotong University

Objectives: The associations between particulate matter (PM) exposure, psychosocial stress and blood cell parameters are bringing novel insights to characterize the early damage of multiple diseases.

Methods: Based on two studies conducted in three Chinses cities using cross-sectional (Beijing, 425 participants) and panel study (Tianjin and Shanghai, 92 participants with 361 repeated measurements) designs, this study explored the associations between short-term exposure to ambient PM and blood cell parameters, and the effect modification by psychosocial stress, which was measured using three psychosocial stress scales including the State Anxiety Inventory (SAI), the Perceived Stress Scale (PSS) and the Self-rating Depression Scale (SDS) and integrated into a composite stress index using the Weighted Quantile Sum regression approach.

Results: Increasing PM2.5 exposure was significantly associated with decreases in red blood cell (RBC) count and mean corpuscular hemoglobin concentration (MCHC), and increases in mean corpuscular volume (MCV), platelets count (PLT) and platelet hematocrit (PCT) in both studies. For instance, a 10 μg/m3 increment in PM2.5 concentration was associated with a 1.04% (95%CI: 0.16%, 1.92%) increase in PLT (4-d) and a 1.09% (95%CI: 0.31%, 1.87%) increase in PCT (4-d) in the cross-sectional study, and a 0.64% (95%CI: 0.06%, 1.22%) increase in PLT (1-d) and a 0.72% (95%CI: 0.33%, 1.11%) increase in PCT (1-d) in the panel study, respectively. In addition, stronger increases in MCV, PLT, and PCT associated with PM2.5 exposure were found in higher composite stress group (0.40%~1.61% in cross-sectional study, 1.00%~1.35% in panel study) compared to lower composite stress group (0.17%~0.40% in cross-sectional study, -0.16%~0.41% in panel study) in both studies (all p for interaction < 0.10).

Conclusions: Short-term exposure to ambient PM2.5 was associated with significant changes in blood cell parameters, and individuals with higher psychosocial stress might be more susceptible to the potential adverse effects of PM2.5 exposure.

Wei Jie Seow - Knowledge, Attitudes, And Practices Towards Second-Hand Smoke Among Participants Of The Singapore Population Health Studies (SPHS)

Prof Wei Jie Seow
National University of Singapore
Saw Swee Hock School of Public Health

Globally, second-hand smoke accounts for approximately 1 million deaths in non-smokers annually. In Singapore, the current control measures only target tobacco consumption, and a lack of understanding of the current knowledge, attitude, and practice (KAP) towards second-hand smoke exposure. A cross-sectional survey was conducted in February 2021, using the Singapore Population Health Studies (SPHS) online panel of 1806 Singaporean adults (aged 21 and above), by administering a self-completed online questionnaire. Descriptive statistics and bivariate analyses were used to compare the second-hand smoke exposure amongst the varying demographics, as well as KAP amongst current smokers, former smokers and never smokers. A multivariate linear regression was fitted to identify factors correlated with the respondents' KAP, and if knowledge and attitude correlates to the respondents' current practices towards second-hand smoke. Results from the study showed that daily second-hand smoke exposure was more frequent in current smokers than never smokers (46.7% vs 22.2%), and more frequent for residents of apartment buildings, such as HDB flats and condominiums, than residents of landed properties (25.1% vs 7.8%). Overall KAP of current smokers were also lower as compared to never smokers and former smokers, suggesting KAP correlation with smoking initiation. Respondents with lower education had lower knowledge and attitude than those with higher education (university or higher). Males typically had better knowledge, but poorer attitude or perception towards second-hand smoke than females. Older respondents also had better KAP than younger respondents. Higher attitude score was correlated to better practices towards second-hand smoke. Future interventions to improve practices towards second-hand smokes should focus on ensuring attitude towards second-hand smoke exposure is ameliorated, which would subsequently reduce overall exposure to second-hand smoke.

Cham Thi Nguyen - Difference in mortalities attributable to PM2.5 across different exposure data sources for 2016-2019 in South Korea

Miss Cham Thi Nguyen
National Cancer Center
Graduate School of Cancer Science and Policy

Background: Inconsistent findings of the disease burden attributable to PM2.5 could be due to the variation of PM2.5 data sources and different findings. This difference could also change over time.

Purposes: We aimed to explore the temporal trends in mortality attributable to PM2.5 across three commonly-used PM2.5 data sources for 2016 - 2019 in South Korea.

Methods: We assessed annual PM2.5 average concentrations in each district for 2016-2019 using three data sources: 1) measurements from regulatory monitoring networks (“Local measurements”), 2) predictions from a local prediction model developed based on regulatory monitoring data (“Local estimates”), and 3) predictions from a global prediction model developed along with satellite-derived PM2.5 estimates (“Global estimates”). For each of the three sets of PM2.5, we computed district-specific attributable deaths for lung cancer, chronic obstructive pneumonia disease, ischemic heart disease, and stroke each year for 2016 - 2019 using district averages of PM2.5, district-level population, province-level mortality, and relative risks. We finally aggregated attributable deaths from all four causes in each district to the country and compared them across three PM2.5 datasets and four years.

Results: Annual average PM2.5 concentrations assessed by local measurements and estimates decreased over four years (26.02-23.5 and 26.17-23.04 µg/m3, respectively), whereas global estimates slightly increased (23.6 - 24.01 µg/m3). Although all three data sources showed the decrease in attributable deaths over four years, this decrease was much larger for local measurements and estimates than global estimates (9,606 - 7,895; 9,630 - 7,741; and 8,526-8,220 respectively).

Conclusions: Our finding of the discrepancy in PM2.5-attributed deaths based on global estimates from local measurements and estimates suggests careful application of global exposure estimates to local health impact analyses.

Post Conference
Wednesday, 22 June 2022
Post-Conference Workshop

Workshop 3: Improve personal brand to leverage networking relationships (Post-conference)

Time: 13:30 - 14:30


Julia Palmer
Relational Strategist & Founder, Relatus

Great opportunities are found in great networks.

This session will focus on personal branding and how to promote yourself within your network (both existing and potential).

Having the confidence to connect with people when first meeting them is vital for your personal and professional success. The next step is managing those relationships to ensure they are sustained and mutually beneficial.

  • Explore the 4 types of networking and decide which one will ensure networking works for you (long term)
  • Learn 3 critical steps to help you create and manage a more viable network and truly connect with those in it.
  • Know the difference between building a simple or strategic network
  • Manage visibility and reap the rewards of influential networking

If 75% of people believe their networks do NOT support the results they need, what actions can you take to beat the odds?

Julia Palmer is a respected Relational Strategist and best known for leading the face-to-face revolution!

Her expertise includes 20 years of practice and research combined with Advanced Certifications in Neuro-linguistics, Emotional Intelligence (Genos International & MSCEIT), Performance Consulting, Training and Assessment. By age 25 Julia was the General Manager of a Multi-Million-dollar global organisation, she has built her career by organising and attending thousands of networking events across all industries internationally. Now as CEO of Relatus, Julia helps you position yourself in professional networks and build your relational capabilities to maximise the human advantage.

Julia presents at functions and conferences around the world. Her clients include; 3M, ANZ, Nestle, QBE and Vodafone. She has authored three books; Relationship networks - The Future of Business', 'Schmoozing the Globe' and 'BUZZ' and appears regularly in TV, Radio and Print Media promoting the growing importance of networking relationships in business today.