Prenatal air pollution exposure and neurodevelopment: A review and blueprint for a harmonized approach within ECHO

Pre-pregnancy ozone and ultrafine particulate matter exposure during second year of life associated with decreased cognitive and adaptive functioning at aged 2-5 years

BACKGROUND

This study sought to investigate the association of prenatal and early life exposure to a mixture of air pollutants on cognitive and adaptive outcomes separately in children with or without autism spectrum disorder (ASD).

METHODS

Utilizing data from the CHARGE case-control study (birth years: 2000-2016), we predicted daily air concentrations of NO2, O3, and particulate matter <0.1 μm (PM0.1), between 0.1 and 2.5 μm (PM0.1-2.5), and between 2.5 and 10 μm (PM2.5-10) using chemical transport models with ground-based monitor adjustments. Exposures were evaluated for pre-pregnancy, each trimester, and the first two years of life. Individual and combined effects of pollutants were assessed with Vineland Adaptive Behavior Scales (VABS) and Mullen Scales of Early Learning (MSEL), separately for children with ASD (n = 660) and children without ASD (typically developing (TD) and developmentally delayed (DD) combined; n = 753) using hierarchical Bayesian Kernel Machine Regression (BKMR) models with three groups: PM size fractions (PM0.1, PM0.1-2.5, PM2.5-10), NO2, and O3.

RESULTS

Pre-pregnancy Ozone was strongly negatively associated with all scores in the non-ASD group (group posterior inclusion probability (gPIP) = 0.83-1.00). The PM group during year 2 was also strongly negatively associated with all scores in the non-ASD group (gPIP = 0.59-0.93), with PM0.1 driving the group association (conditional PIP (cPIP) = 0.73-0.96). Weaker and less consistent associations were observed between PM0.1-2.5 during pre-pregnancy and ozone during year 1 and VABS scores in the ASD group.

CONCLUSIONS

These findings prompt further investigation into ozone and ultrafine PM as potential environmental risk factors for neurodevelopment.

The association between prenatal oxidative stress levels measured by isoprostanes and offspring neurodevelopmental outcomes at 36 months

Oxidative stress during pregnancy has been a mechanistic pathway implicated in autism development, yet few studies have examined this association directly. Here, we examined the association of prenatal levels of 8-iso-PGF2α, a widely used measure of oxidative stress, and several neurodevelopmental outcomes related to autism in children. Participants included 169 mother-child pairs from the Early Autism Risk Longitudinal Investigation (EARLI), which enrolled mothers who had an autistic child from a previous pregnancy and followed them through a subsequent pregnancy and until that child reached age 3 years. Maternal urine samples were collected during the second trimester of pregnancy and were later measured for levels of isoprostanes. Child neurodevelopmental assessments included the Mullen Scales of Early Learning (MSEL), the Social Responsiveness Scale (SRS), and the Vineland Adaptive Behavior Scale (VABS), and were conducted around 36 months of age. Primary analyses examined associations between interquartile range (IQR) increases in 8-iso-PGF2α levels, and total composite scores from each assessment using quantile regression. In adjusted analyses, we did not observe statistically significant associations, though estimates suggested modestly lower cognitive scores (β for MSEL = -3.68, 95% CI: -10.09, 2.70), and minor increases in autism-related trait scores (β for SRS T score = 1.68, 95% CI: -0.24, 3.60) with increasing 8-iso-PGF2α. These suggestive associations between decreased cognitive scores and increased autism-related traits with increasing prenatal oxidative stress point to the need for continued investigation in larger samples of the role of oxidative stress as a mechanistic pathway in autism and related neurodevelopmental outcomes.

Potential Effects of Low-Level Toluene Exposure on the Nervous System of Mothers and Infants

In day-to-day living, individuals are exposed to various environmentally hazardous substances that have been associated with diverse diseases. Exposure to air pollutants can occur during breathing, posing a considerable risk to those with environmental health vulnerabilities. Among vulnerable individuals, maternal exposure can negatively impact the mother and child in utero. The developing fetus is particularly vulnerable to environmentally hazardous substances, with potentially greater implications. Among air pollutants, toluene is neurotoxic, and its effects have been widely explored. However, the impact of low-level toluene exposure in daily life remains unclear. Herein, we evaluated 194 mothers and infants from the Growing children's health and Evaluation of Environment (GREEN) cohort to determine the possible effects of early-life toluene exposure on the nervous system. Using Omics experiments, the effects of toluene were confirmed based on epigenetic changes and altered mRNA expression. Various epigenetic changes were identified, with upregulated expression potentially contributing to diseases such as glioblastoma and Alzheimer's, and downregulated expression being associated with structural neuronal abnormalities. These findings were detected in both maternal and infant groups, suggesting that maternal exposure to environmental hazardous substances can negatively impact the fetus. Our findings will facilitate the establishment of environmental health policies, including the management of environmentally hazardous substances for vulnerable groups.

Risk assessment of Benzene, Toluene, Ethyl benzene, and Xylene (BTEX) in the atmospheric air around the world: A review

Volatile organic compounds, such as BTEX, have been the subject of numerous debates due to their detrimental effects on the environment and human health. Human beings have had a significant role in the emergence of this situation. Even though US EPA, WHO, and other health-related organizations have set standard limits as unhazardous levels, it has been observed that within or even below these limits, constant exposure to these toxic chemicals results in negative consequences as well. According to these facts, various studies have been carried out all over the world - 160 of which are collected within this review article, so that experts and governors may come up with effective solutions to manage and control these toxic chemicals. The outcome of this study will serve the society to evaluate and handle the risks of being exposed to BTEX. In this review article, the attempt was to collect the most accessible studies relevant to risk assessment of BTEX in the atmosphere, and for the article to contain least bias, it was reviewed and re-evaluated by all authors, who are from different institutions and backgrounds, so that the insights of the article remain unbiased. There may be some limitations to consistency or precision in some points due to the original sources, however the attempt was to minimize them as much as possible.

The Health-Related and Learning Performance Effects of Air Pollution and Other Urban-Related Environmental Factors on School-Age Children and Adolescents-A Scoping Review of Systematic Reviews

PURPOSE OF REVIEW

This scoping review aims to assess the impact of air pollution, traffic noise, heat, and green and blue space exposures on the physical and cognitive development of school-age children and adolescents. While existing evidence indicates adverse effects of transport-related exposures on their health, a comprehensive scoping review is necessary to consolidate findings on various urban environmental exposures' effects on children's development.

RECENT FINDINGS

There is consistent evidence on how air pollution negatively affects children's cognitive and respiratory health and learning performance, increasing their susceptibility to diseases in their adult life. Scientific evidence on heat and traffic noise, while less researched, indicates that they negatively affect children's health. On the contrary, green space exposure seems to benefit or mitigate these adverse effects, suggesting a potential strategy to promote children's cognitive and physical development in urban settings. This review underscores the substantial impact of urban exposures on the physical and mental development of children and adolescents. It highlights adverse health effects that can extend into adulthood, affecting academic opportunities and well-being beyond health. While acknowledging the necessity for more research on the mechanisms of air pollution effects and associations with heat and noise exposure, the review advocates prioritizing policy changes and urban planning interventions. This includes minimizing air pollution and traffic noise while enhancing urban vegetation, particularly in school environments, to ensure the healthy development of children and promote lifelong health.

Intrapartum exposure to synthetic oxytocin, maternal BMI, and neurodevelopmental outcomes in children within the ECHO consortium

BACKGROUND

Synthetic oxytocin (sOT) is frequently administered during parturition. Studies have raised concerns that fetal exposure to sOT may be associated with altered brain development and risk of neurodevelopmental disorders. In a large and diverse sample of children with data about intrapartum sOT exposure and subsequent diagnoses of two prevalent neurodevelopmental disorders, i.e., attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), we tested the following hypotheses: (1) Intrapartum sOT exposure is associated with increased odds of child ADHD or ASD; (2) associations differ across sex; (3) associations between intrapartum sOT exposure and ADHD or ASD are accentuated in offspring of mothers with pre-pregnancy obesity.

METHODS

The study sample comprised 12,503 participants from 44 cohort sites included in the Environmental Influences on Child Health Outcomes (ECHO) consortium. Mixed-effects logistic regression analyses were used to estimate the association between intrapartum sOT exposure and offspring ADHD or ASD (in separate models). Maternal obesity (pre-pregnancy BMI ≥ 30 kg/m2) and child sex were evaluated for effect modification.

RESULTS

Intrapartum sOT exposure was present in 48% of participants. sOT exposure was not associated with increased odds of ASD (adjusted odds ratio [aOR] 0.86; 95% confidence interval [CI], 0.71-1.03) or ADHD (aOR 0.89; 95% CI, 0.76-1.04). Associations did not differ by child sex. Among mothers with pre-pregnancy obesity, sOT exposure was associated with lower odds of offspring ADHD (aOR 0.72; 95% CI, 0.55-0.96). No association was found among mothers without obesity (aOR 0.97; 95% CI, 0.80-1.18).

CONCLUSIONS

In a large, diverse sample, we found no evidence of an association between intrapartum exposure to sOT and odds of ADHD or ASD in either male or female offspring. Contrary to our hypothesis, among mothers with pre-pregnancy obesity, sOT exposure was associated with lower odds of child ADHD diagnosis.

Climate change, air pollution and maternal and newborn health: An overview of reviews of health outcomes

Background

Climate change represents a fundamental threat to human health, with pregnant women and newborns being more susceptible than other populations. In this review, we aimed to describe the current landscape of available epidemiological evidence on key climate risks on maternal and newborn health (MNH).

Methods

We sought to identify published systematic and scoping reviews investigating the impact of different climate hazards and air pollution on MNH outcomes. With this in mind, we developed a systematic search strategy based on the concepts of 'climate/air pollution hazards, 'maternal health,' and 'newborn health,' with restrictions to reviews published between 1 January 2010 and 6 February 2023, but without geographical or language restriction. Following full text screening and data extraction, we synthesised the results using narrative synthesis.

Results

We found 79 reviews investigating the effects of climate hazards on MNH, mainly focussing on outdoor air pollution (n = 47, 59%), heat (n = 24, 30%), and flood/storm disasters (n = 7, 9%). Most were published after 2015 (n = 60, 76%). These reviews had consistent findings regarding the positive association of exposure to heat and to air pollution with adverse birth outcomes, particularly preterm birth. We found limited evidence for impacts of climate-related food and water security on MNH and did not identify any reviews on climate-sensitive infectious diseases and MNH.

Conclusions

Climate change could undermine recent improvements in maternal and newborn health. Our review provides an overview of key climate risks to MNH. It could therefore be useful to the MNH community to better understand the MNH needs for each climate hazard and to strengthen discussions on evidence and research gaps and potential actions. Despite the lack of comprehensive evidence for some climate hazards and for many maternal, perinatal, and newborn outcomes, we observed repeated findings of the impact of heat and air pollutants on birth outcomes, particularly preterm birth. It is time for policy dialogue to follow to specifically design climate policy and actions to protect the needs of MNH.

Lifetime exposure to air pollution and academic achievement: A nationwide cohort study in Denmark

Recent research suggests a link between air pollution and cognitive development in children, and studies on air pollution and academic achievement are emerging. We conducted a nationwide cohort study in Denmark to explore the associations between lifetime exposure to air pollution and academic performance in 9th grade. The study encompassed 785,312 children born in Denmark between 1989 and 2005, all of whom completed 9th-grade exit examinations. Using linear mixed models with a random intercept for each school, we assessed the relationship between 16 years of exposure to PM2.5, PM10, and gaseous pollutants and Grade Point Averages (GPA) in exit examinations, covering subjects such as Danish literature, Danish writing, English, mathematics, and natural sciences. The study revealed that a 5 µg/m3 increase in PM2.5 and PM10 was associated with a decrease of 0.99 (95 % Confidence Intervals: -1.05, -0.92) and 0.46 (-0.50, -0.41) in GPA, respectively. Notably, these negative associations were more pronounced in mathematics and natural sciences compared to language-related subjects. Additionally, girls and children with non-Danish mothers were found to be particularly susceptible to the adverse effects of air pollution exposure. These results underscore the potential long-term consequences of air pollution on academic achievement, emphasizing the significance of interventions that foster healthier environments for children's cognitive development.

PM2.5 threshold exceedances during the prenatal period and risk of intellectual disability

BACKGROUND

Research demonstrates that chronic exposure to fine particulates (PM2.5) increases risks of neurodevelopmental conditions, such as intellectual disability (ID). Few studies have examined neurodevelopmental health impacts of pollution spikes exceeding 24-h (24-h) PM2.5 guidelines, despite relevance to the regulatory landscape. The current potential for regulatory changes to 24-h PM2.5 standards in the United States makes research on exceedances relevant.

OBJECTIVE

To examine associations between 24-h PM2.5 exceedances and the risk of ID.

METHODS

We conducted a retrospective case-control study of a sample of children in Utah, USA. We used generalized estimating equations to predict odds of ID based on the number of 24-h PM2.5 exceedance days during the preconception period and three trimesters of pregnancy. Exceedance days are defined as per current World Health Organization (WHO) [≥15 μg/m3] and current US Environmental Protection Agency (EPA) [≥35 μg/m3] 24-h guidelines.

RESULTS

PM2.5 exceedances are associated with ID risk during the preconception and first trimester periods and not the second and third trimesters. During the preconception period, each day exceeding 15 μg/m3 or 35 μg/m3 was associated with a 1.023 (CI: 1.011-1.040) or 1.042 (CI: 1.026-1.059, p < 0.001) increase in odds of ID, respectively. During the first trimester, each day exceeding 15 μg/m3 or 35 μg/m3 was associated with a 1.032 (CI: 1.017-1.047) or 1.059 (CI: 1.030-1.088) increase in odds of ID, respectively.

IMPACT STATEMENT

Potential regulatory movement on the US 24-h PM2.5 standard makes research that explicitly studies exceedances highly relevant. Yet few studies examine health effects of exceeding 24-h guidelines for any air pollutants. This study fills important gaps in the literature by examining associations between odds of intellectual disability and the count of days exceeding current 24-h PM2.5 guidelines, as established by the World Health Organization and US Environmental Protection Agency, during the prenatal period. We find that exceedances of both sets of guidelines, during the preconception and first trimester periods, are associated with ID risk.

Susceptible windows of prenatal and postnatal fine particulate matter exposures and attention-deficit hyperactivity disorder symptoms in early childhood

Few prior studies have explored windows of susceptibility to fine particulate matter (PM2.5) in both the prenatal and postnatal periods and children's attention-deficit/hyperactivity disorder (ADHD) symptoms. We analyzed data from 1416 mother-child pairs from the Spanish INMA (INfancia y Medio Ambiente) Study (2003-2008). Around 5 years of age, teachers reported the number of ADHD symptoms (i.e., inattention, hyperactivity/impulsivity) using the ADHD Diagnostic and Statistical Manual of Mental Disorders. Around 7 years of age, parents completed the Conners' Parent Rating Scales, from which we evaluated the ADHD index, cognitive problems/inattention, hyperactivity, and oppositional subscales, reported as age- and sex-standardized T-scores. Daily residential PM2.5 exposures were estimated using a two-stage random forest model with temporal back-extrapolation and averaged over 1-week periods in the prenatal period and 4-week periods in the postnatal period. We applied distributed lag non-linear models within the Bayesian hierarchical model framework to identify susceptible windows of prenatal or postnatal exposure to PM2.5 (per 5-μg/m3) for ADHD symptoms. Models were adjusted for relevant covariates, and cumulative effects were reported by aggregating risk ratios (RRcum) or effect estimates (βcum) across adjacent susceptible windows. A similar susceptible period of exposure to PM2.5 (1.2-2.9 and 0.9-2.7 years of age, respectively) was identified for hyperactivity/impulsivity symptoms assessed ~5 years (RRcum = 2.72, 95% credible interval [CrI] = 1.98, 3.74) and increased hyperactivity subscale ~7 years (βcum = 3.70, 95% CrI = 2.36, 5.03). We observed a susceptibility period to PM2.5 on risk of hyperactivity/impulsivity symptoms ~5 years in gestational weeks 16-22 (RRcum = 1.36, 95% CrI = 1.22, 1.52). No associations between PM2.5 exposure and other ADHD symptoms were observed. We report consistent evidence of toddlerhood as a susceptible window of PM2.5 exposure for hyperactivity in young children. Although mid-pregnancy was identified as a susceptible period of exposure on hyperactivity symptoms in preschool-aged children, this association was not observed at the time children were school-aged.

Linking Prenatal Environmental Exposures to Lifetime Health with Epigenome-Wide Association Studies: State-of-the-Science Review and Future Recommendations

BACKGROUND

The prenatal environment influences lifetime health; epigenetic mechanisms likely predominate. In 2016, the first international consortium paper on cigarette smoking during pregnancy and offspring DNA methylation identified extensive, reproducible exposure signals. This finding raised expectations for epigenome-wide association studies (EWAS) of other exposures.

OBJECTIVE

We review the current state-of-the-science for DNA methylation associations across prenatal exposures in humans and provide future recommendations.

METHODS

We reviewed 134 prenatal environmental EWAS of DNA methylation in newborns, focusing on 51 epidemiological studies with meta-analysis or replication testing. Exposures spanned cigarette smoking, alcohol consumption, air pollution, dietary factors, psychosocial stress, metals, other chemicals, and other exogenous factors. Of the reproducible DNA methylation signatures, we examined implementation as exposure biomarkers.

RESULTS

Only 19 (14%) of these prenatal EWAS were conducted in cohorts of 1,000 or more individuals, reflecting the still early stage of the field. To date, the largest perinatal EWAS sample size was 6,685 participants. For comparison, the most recent genome-wide association study for birth weight included more than 300,000 individuals. Replication, at some level, was successful with exposures to cigarette smoking, folate, dietary glycemic index, particulate matter with aerodynamic diameter < 10 μ m and < 2.5 μ m , nitrogen dioxide, mercury, cadmium, arsenic, electronic waste, PFAS, and DDT. Reproducible effects of a more limited set of prenatal exposures (smoking, folate) enabled robust methylation biomarker creation.

DISCUSSION

Current evidence demonstrates the scientific premise for reproducible DNA methylation exposure signatures. Better powered EWAS could identify signatures across many exposures and enable comprehensive biomarker development. Whether methylation biomarkers of exposures themselves cause health effects remains unclear. We expect that larger EWAS with enhanced coverage of epigenome and exposome, along with improved single-cell technologies and evolving methods for integrative multi-omics analyses and causal inference, will expand mechanistic understanding of causal links between environmental exposures, the epigenome, and health outcomes throughout the life course. https://doi.org/10.1289/EHP12956.

Opportunities for Examining Child Health Impacts of Early-Life Nutrition in the ECHO Program: Maternal and Child Dietary Intake Data from Pregnancy to Adolescence

Background

Longitudinal measures of diet spanning pregnancy through adolescence are needed from a large, diverse sample to advance research on the effect of early-life nutrition on child health. The Environmental influences on Child Health Outcomes (ECHO) Program, which includes 69 cohorts, >33,000 pregnancies, and >31,000 children in its first 7-y cycle, provides such data, now publicly available.

Objectives

This study aimed to describe dietary intake data available in the ECHO Program as of 31 August, 2022 (end of year 6 of Cycle 1) from pregnancy through adolescence, including estimated sample sizes, and to highlight the potential for future analyses of nutrition and child health.

Methods

We identified and categorized ECHO Program dietary intake data, by assessment method, participant (pregnant person or child), and life stage of data collection. We calculated the number of maternal-child dyads with dietary data and the number of participants with repeated measures. We identified diet-related variables derived from raw dietary intake data and nutrient biomarkers measured from biospecimens.

Results

Overall, 66 cohorts (26,941 pregnancies, 27,103 children, including 22,712 dyads) across 34 US states/territories provided dietary intake data. Dietary intake assessments included 24-h recalls (1548 pregnancies and 1457 children), food frequency questionnaires (4902 and 4117), dietary screeners (8816 and 23,626), and dietary supplement use questionnaires (24,798 and 26,513). Repeated measures were available for ∼70%, ∼30%, and ∼15% of participants with 24-h recalls, food frequency questionnaires, and dietary screeners, respectively. The available diet-related variables describe nutrient and food intake, diet patterns, and breastfeeding practices. Overall, 17% of participants with dietary intake data had measured nutrient biomarkers.

Conclusions

ECHO cohorts have collected longitudinal dietary intake data spanning pregnancy through adolescence from a geographically, socioeconomically, and ethnically diverse US sample. As data collection continues in Cycle 2, these data present an opportunity to advance the field of nutrition and child health.

The Role of Environmental Chemicals in the Etiology of Learning Difficulties: A Novel Theoretical Framework

Children from economically disadvantaged communities have a disproportionate risk of exposure to chemicals, social stress, and learning difficulties. Although animal models and epidemiologic studies link exposures and neurodevelopment, little focus has been paid to academic outcomes in environmental health studies. Similarly, in the educational literature, environmental chemical exposures are overlooked as potential etiologic factors in learning difficulties. We propose a theoretical framework for the etiology of learning difficulties that focuses on these understudied exogenous factors. We discuss findings from animal models and longitudinal, prospective birth cohort studies that support this theoretical framework. Studies reviewed point to the effects of prenatal exposure to polycyclic aromatic hydrocarbons on reading comprehension and math skills via effects on inhibitory control processes. Long term, this work will help close the achievement gap in the United States by identifying behavioral and neural pathways from prenatal exposures to learning difficulties in children from economically disadvantaged families.

Prenatal and childhood exposure to ambient air pollution and cognitive function in school-age children: Examining sensitive windows and sex-specific associations

BACKGROUND

Combined effect of both prenatal and early postnatal exposure to ambient air pollution on child cognition has rarely been investigated and periods of sensitivity are unknown. This study explores the temporal relationship between pre- and postnatal exposure to PM10, PM2.5, NO2 and child cognitive function.

METHODS

Using validated spatiotemporally resolved exposure models, pre- and postnatal daily PM2.5, PM10 (satellite based, 1 km resolution) and NO2 (chemistry-transport model, 4 km resolution) concentrations at the mother's residence were estimated for 1271 mother-child pairs from the French EDEN and PELAGIE cohorts. Scores representative of children's General, Verbal and Non-Verbal abilities at 5-6 years were constructed based on subscale scores from the WPPSI-III, WISC-IV or NEPSY-II batteries, using confirmatory factor analysis (CFA). Associations of both prenatal (first 35 gestational weeks) and postnatal (60 months after birth) exposure to air pollutants with child cognition were explored using Distributed Lag Non-linear Models adjusted for confounders.

RESULTS

Increased maternal exposure to PM10, PM2.5 and NO2, during sensitive windows comprised between the 15th and the 33rd gestational weeks, was associated with lower males' General and Non-verbal abilities. Higher postnatal exposure to PM2.5 between the 35th and 52nd month of life was associated with lower males' General, Verbal and Non-verbal abilities. Some protective associations were punctually observed for the very first gestational weeks or months of life for both males and females and the different pollutants and cognitive scores.

DISCUSSION

These results suggest poorer cognitive function at 5-6 years among males following increased maternal exposure to PM10, PM2.5 and NO2 during mid-pregnancy and child exposure to PM2.5 around 3-4 years. Apparent protective associations observed are unlikely to be causal and might be due to live birth selection bias, chance finding or residual confounding.

Prenatal ambient air pollutant mixture exposure and neurodevelopment in urban children in the Northeastern United States

BACKGROUND

Studies of prenatal air pollution (AP) exposure on child neurodevelopment have mostly focused on a single pollutant. We leveraged daily exposure data and implemented novel data-driven statistical approaches to assess effects of prenatal exposure to a mixture of seven air pollutants on cognitive functioning in school-age children from an urban pregnancy cohort.

METHODS

Analyses included 236 children born at ≥37 weeks gestation. Maternal prenatal daily exposure levels for nitrogen dioxide (NO2), ozone (O3), and constituents of fine particles [elemental carbon (EC), organic carbon (OC), nitrate (NO3-), sulfate (SO42-), ammonium (NH4+)] were estimated based on residential addresses using validated satellite-based hybrid models or global 3-D chemical-transport models. Children completed Wide Range Assessment of Memory and Learning (WRAML-2) and Conners' Continuous Performance Test (CPT-II) at 6.5 ± 0.9 years of age. Time-weighted levels for mixture pollutants were estimated using Bayesian Kernel Machine Regression Distributed Lag Models (BKMR-DLMs), with which we also explored the interactions in the exposure-response functions among pollutants. Resulting time-weighted exposure levels were used in Weighted Quantile Sum (WQS) regressions to examine AP mixture effects on outcomes, adjusted for maternal age, education, child sex, and prenatal temperature.

RESULTS

Mothers were primarily ethnic minorities (81% Hispanic and/or black) reporting ≤12 years of education (68%). Prenatal AP mixture (per unit increase in WQS estimated AP index) was associated with decreased WRAML-2 general memory (GM; β = -0.64, 95%CI = -1.40, 0.00) and memory-related attention/concentration (AC; β = -1.03, 95%CI = -1.78, -0.27) indices, indicating poorer memory functioning, as well as increased CPT-II omission errors (OE; β = 1.55, 95%CI = 0.34, 2.77), indicating increased attention problems. When stratified by sex, association with AC index was significant among girls, while association with OE was significant among boys. Traffic-related pollutants (NO2, OC, EC) and SO42- were major contributors to these associations. There was no significant evidence of interactions among mixture components.

CONCLUSIONS

Prenatal exposure to an AP mixture was associated with child neurocognitive outcomes in a sex- and domain-specific manner.

Toward an understanding of the role of the exposome on fragile X phenotypes

Fragile X syndrome (FXS) is the leading known monogenetic cause of autism with an estimated 21-50% of FXS individuals meeting autism diagnostic criteria. A critical gap in medical care for persons with autism is an understanding of how environmental exposures and gene-environment interactions affect disease outcomes. Our research indicates more severe neurological and metabolic outcomes (seizures, autism, increased body weight) in mouse and human models of autism spectrum disorders (ASD) as a function of diet. Thus, early-life exposure to chemicals in the diet could cause or exacerbate disease outcomes. Herein, we review the effects of potential dietary toxins, i.e., soy phytoestrogens, glyphosate, and polychlorinated biphenyls (PCB) in FXS and other autism models. The rationale is that potentially toxic chemicals in the diet, particularly infant formula, could contribute to the development and/or severity of ASD and that further study in this area has potential to improve ASD outcomes through dietary modification.

CA, Catellier D, Cordero JF, Croen L, Dabelea D, Deoni S, D’Sa V, Duarte CS, Dunlop AL, Elliott AJ, Farzan SF, Ferrara A, Ganiban JM, Gern JE, Giardino AP, Towe-Goodman NR, Gold DR, Habre R, Hamra GB, Hartert T, Herbstman JB, Hertz-Picciotto I, Hipwell AE, Karagas MR, Karr CJ, Keenan K, Kerver JM, Koinis-Mitchell D, Lau B, Lester BM, Leve LD, Leventhal B, LeWinn KZ, Lewis J, Litonjua AA, Lyall K, Madan JC, McEvoy CT, McGrath M, Meeker JD, Miller RL, Morello-Frosch R, Neiderhiser JM, O’Connor TG, Oken E, O’Shea M, Paneth N, Porucznik CA, Sathyanarayana S, Schantz SL, Spindel ER, Stanford JB, Stroustrup A, Teitelbaum SL, Trasande L, Volk H, Wadhwa PD, Weiss ST, Woodruff TJ, Wright RJ, Zhao Q, Jacobson LP, Influences on Child Health Outcomes ,OBOPCFE. The Environmental Influences on Child Health Outcomes (ECHO)-Wide Cohort

The Environmental Influences on Child Health Outcomes (ECHO)-Wide Cohort Study (EWC), a collaborative research design comprising 69 cohorts in 31 consortia, was funded by the National Institutes of Health (NIH) in 2016 to improve children's health in the United States. The EWC harmonizes extant data and collects new data using a standardized protocol, the ECHO-Wide Cohort Data Collection Protocol (EWCP). EWCP visits occur at least once per life stage, but the frequency and timing of the visits vary across cohorts. As of March 4, 2022, the EWC cohorts contributed data from 60,553 children and consented 29,622 children for new EWCP data and biospecimen collection. The median (interquartile range) age of EWCP-enrolled children was 7.5 years (3.7-11.1). Surveys, interviews, standardized examinations, laboratory analyses, and medical record abstraction are used to obtain information in 5 main outcome areas: pre-, peri-, and postnatal outcomes; neurodevelopment; obesity; airways; and positive health. Exposures include factors at the level of place (e.g., air pollution, neighborhood socioeconomic status), family (e.g., parental mental health), and individuals (e.g., diet, genomics).

Characterisation of personalised air pollution exposure in pregnant women participating in a birth cohort study

BACKGROUND

Air pollution is a health risk in pregnant women and children. Despite the importance of refined exposure assessment, the characterisation of personalised air pollution exposure remains a challenge in paediatric and perinatal epidemiology.

OBJECTIVE

We used portable personal air monitors to characterise personalised exposure to air pollutants in pregnant women.

METHODS

Between November 2019 and May 2022, we offered personal air monitors to pregnant women participating in a birth cohort in New York City. During pregnancy, women used air monitors, which measured particulate matter (PM), nitrogen dioxide (NO2 ), and volatile organic compounds (average use = 14 days). Data were stored in real-time on a secure database via synchronisation with a smartphone application. Of 497 women who agreed to use air monitors, 273 women (55%) were successful in using air monitors for longer than a day. For these participants, we identified daily patterns of exposure to air pollutants using functional principal component analysis (3827 days of air monitoring).

RESULTS

Compared to women with no pollution data (n = 224), women who successfully used monitors were more likely to be non-Hispanic White and Asian (vs. Hispanic), nulliparous, unemployed, married/partnered, and received the device in-person (vs. mailed). We identified different daily patterns of exposure to air pollutants. The most dominant pattern for all pollutants was low exposure levels with little variations within 24 h, followed by a pattern that showed differences between day and night levels. NO2 had higher daily variations compared to PM.

CONCLUSIONS

Small wearables are useful for the measurement of personalised air pollution exposure in birth cohorts and identify daily patterns that cannot be captured otherwise. Successful participation, however, depends on certain individual characteristics. Future studies should consider strategies in design and analysis to account for selective participation.

Evidence for an association of prenatal exposure to particulate matter with clinical severity of Autism Spectrum Disorder

Early-life exposure to air pollutants, including ozone (O₃), particulate matter (PM_2.5 or PM₁₀, depending on diameter of particles), nitrogen dioxide (NO₂) and sulfur dioxide (SO₂) has been suggested to contribute to the etiology of Autism Spectrum Disorder (ASD). In this study, we used air quality monitoring data to examine whether mothers of children with ASD were exposed to high levels of air pollutants during critical periods of pregnancy, and if higher exposure levels may lead to a higher clinical severity in their offspring. We used public data from the Portuguese Environment Agency to estimate exposure to these pollutants during the first, second and third trimesters of pregnancy, full pregnancy and first year of life of the child, for 217 subjects with ASD born between 2003 and 2016. These subjects were stratified in two subgroups according to clinical severity, as defined by the Autism Diagnostic Observational Schedule (ADOS). For all time periods, the average levels of PM_2.5, PM₁₀ and NO₂ to which the subjects were exposed were within the admissible levels defined by the European Union. However, a fraction of these subjects showed exposure to levels of PM_2.5 and PM₁₀ above the admissible threshold. A higher clinical severity was associated with higher exposure to PM_2.5 (p = 0.001), NO₂ (p = 0.011) and PM₁₀ (p = 0.041) during the first trimester of pregnancy, when compared with milder clinical severity. After logistic regression, associations with higher clinical severity were identified for PM_2.5 exposure during the first trimester (p = 0.002; OR = 1.14, 95%CI: 1.05-1.23) and full pregnancy (p = 0.04; OR = 1.07, 95%CI: 1.00-1.15) and for PM₁₀ (p = 0.02; OR = 1.07, 95%CI: 1.01-1.14) exposure during the third trimester. Exposure to PM is known to elicit neuropathological mechanisms associated with ASD, including neuroinflammation, mitochondrial disruptions, oxidative stress and epigenetic changes. These results offer new insights on the impact of early-life exposure to PM in ASD clinical severity.

Air pollution during the perinatal period and neurodevelopment in children: A national population study in Taiwan

AIM

To evaluate the association between ambient particulate matter no larger than 2.5 μm in diameter (PM2.5 ) during the prenatal and postnatal periods and infant neurodevelopmental parameters.

METHOD

We conducted a population-based birth cohort study using the Taiwan Birth Cohort Study. Participants were assessed for developmental conditions through home interviews at 6 months and 18 months of age. Exposure to PM2.5 of mothers and infants during perinatal periods was estimated using hybrid kriging/land-use regression. The exposure was linked to each participant by home address. Logistic regression was then conducted to determine the risk of neurodevelopmental delay in relation to PM2.5 .

RESULTS

A total of 17 683 term singletons without congenital malformations were included in the final analysis. PM2.5 during the second trimester was associated with increased risks of delays in gross motor neurodevelopmental milestones (adjusted odds ratio [aOR] 1.09 per 10 μg/m3 increase in exposure to PM2.5 ). Delayed fine motor development was also found to be related to exposure to PM2.5 in the second and third trimesters (aOR 1.06), as was personal-social skill (aOR 1.11 for the second trimester and 1.06 for the third). These neurodevelopmental parameters were unrelated to postnatal PM2.5 exposure.

INTERPRETATION

Exposure to ambient PM2.5 during pregnancy was significantly related to delay in gross motor, fine motor, and personal-social development in this population-based study.

WHAT THIS PAPER ADDS

Prenatal exposure to higher PM2.5 was associated with increased risk of delayed early neurodevelopment. The critical period for delayed gross motor development was the second trimester. The critical period for fine motor and personal-social development was the second and third trimesters.

Air pollution and child health impacts of decarbonization in 16 global cities: Modelling study

Most research on the air pollution-related health effects of decarbonization has focused on adults. We assess the potential health benefits that could be achieved in children and young people in a global sample of 16 cities through global decarbonization actions. We modelled annual average concentrations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) at 1x1 km resolution in the cities using a general circulation/atmospheric chemistry model assuming removal of all global combustion-related emissions from land transport, industries, domestic energy use and power generation. We modelled the impact on childhood asthma incidence and adverse birth outcomes (low birthweight, pre-term births) using published exposure-response relationships. Removal of combustion emissions was estimated to decrease annual average PM_2.5 by between 2.9 μg/m³ (8.4%) in Freetown and 45.4 μg/m³ (63.7%) in Dhaka. For NO₂, the range was from 0.3 ppb (7.9%) in Freetown to 18.8 ppb (92.3%) in Mexico City. Estimated reductions in asthma incidence ranged from close to zero in Freetown, Tamale and Harare to 149 cases per 100,000 population in Los Angeles. For pre-term birth, modelled impacts ranged from a reduction of 135 per 100,000 births in Dar es Salaam to 2,818 per 100,000 births in Bhubaneswar and, for low birthweight, from 75 per 100,000 births in Dar es Salaam to 2,951 per 100,000 births in Dhaka. The large variations chiefly reflect differences in the magnitudes of air pollution reductions and estimated underlying disease rates. Across the 16 cities, the reduction in childhood asthma incidence represents more than one-fifth of the current burden, and an almost 10% reduction in pre-term and low birthweight births. Decarbonization actions that remove combustion-related emissions contributing to ambient PM_2.5 and NO₂ would likely lead to substantial but geographically-varied reductions in childhood asthma and adverse birth outcomes, though there are uncertainties in causality and the precision of estimates.

Prenatal Exposure to Air Pollutants and Attentional Deficit Hyperactivity Disorder Development in Children: A Systematic Review

Up to 9.5% of the world's population is diagnosed with attention deficit/hyperactivity disorder (ADHD), making it one of the most common childhood disorders. Air pollutants could be considered an environmental risk condition for ADHD, but few studies have specifically investigated the effect of prenatal exposure. The current paper reviews the studies conducted on the association between prenatal air pollutants (PM, NO_x, SO₂, O₃, CO and PAH) and ADHD development in children. From the 890 studies searched through PubMed, Google Scholar, Scopus, and Web of Science, 15 cohort studies met the inclusion criteria. NOS and WHO guidelines were used for quality and risk of bias assessment. The accumulative sample was 589,400 of children aged 3-15 years. Most studies reported an association between ADHD symptoms and prenatal PAH and PM exposure. Data available on NO₂ and SO₂ were inconsistent, whereas the effect of CO/O₃ is barely investigated. We observed heterogeneity through an odd ratio forest plot, and discrepancies in methodologies across the studies. Eight of the fifteen studies were judged to be of moderate risk of bias in the outcome measurement. In a nutshell, future studies should aim to minimize heterogeneity and reduce bias by ensuring a more representative sample, standardizing exposure and outcome assessments.

Prenatal exposure to air pollution is associated with structural changes in the neonatal brain

BACKGROUND

Prenatal exposure to air pollution is associated with adverse neurologic consequences in childhood. However, the relationship between in utero exposure to air pollution and neonatal brain development is unclear.

METHODS

We modelled maternal exposure to nitrogen dioxide (NO2) and particulate matter (PM2.5 and PM10) at postcode level between date of conception to date of birth and studied the effect of prenatal air pollution exposure on neonatal brain morphology in 469 (207 male) healthy neonates, with gestational age of ≥36 weeks. Infants underwent MR neuroimaging at 3 Tesla at 41.29 (36.71-45.14) weeks post-menstrual age (PMA) as part of the developing human connectome project (dHCP). Single pollutant linear regression and canonical correlation analysis (CCA) were performed to assess the relationship between air pollution and brain morphology, adjusting for confounders and correcting for false discovery rate.

RESULTS

Higher exposure to PM10 and lower exposure to NO2 was strongly canonically correlated to a larger relative ventricular volume, and moderately associated with larger relative size of the cerebellum. Modest associations were detected with higher exposure to PM10 and lower exposure to NO2 and smaller relative cortical grey matter and amygdala and hippocampus, and larger relaive brainstem and extracerebral CSF volume. No associations were found with white matter or deep grey nuclei volume.

CONCLUSIONS

Our findings show that prenatal exposure to air pollution is associated with altered brain morphometry in the neonatal period, albeit with opposing results for NO2 and PM10. This finding provides further evidence that reducing levels of maternal exposure to particulate matter during pregnancy should be a public health priority and highlights the importance of understanding the impacts of air pollution on this critical development window.

The Minderoo-Monaco Commission on Plastics and Human Health

Background

Plastics have conveyed great benefits to humanity and made possible some of the most significant advances of modern civilization in fields as diverse as medicine, electronics, aerospace, construction, food packaging, and sports. It is now clear, however, that plastics are also responsible for significant harms to human health, the economy, and the earth's environment. These harms occur at every stage of the plastic life cycle, from extraction of the coal, oil, and gas that are its main feedstocks through to ultimate disposal into the environment. The extent of these harms not been systematically assessed, their magnitude not fully quantified, and their economic costs not comprehensively counted.

Goals

The goals of this Minderoo-Monaco Commission on Plastics and Human Health are to comprehensively examine plastics' impacts across their life cycle on: (1) human health and well-being; (2) the global environment, especially the ocean; (3) the economy; and (4) vulnerable populations-the poor, minorities, and the world's children. On the basis of this examination, the Commission offers science-based recommendations designed to support development of a Global Plastics Treaty, protect human health, and save lives.

Report Structure

This Commission report contains seven Sections. Following an Introduction, Section 2 presents a narrative review of the processes involved in plastic production, use, and disposal and notes the hazards to human health and the environment associated with each of these stages. Section 3 describes plastics' impacts on the ocean and notes the potential for plastic in the ocean to enter the marine food web and result in human exposure. Section 4 details plastics' impacts on human health. Section 5 presents a first-order estimate of plastics' health-related economic costs. Section 6 examines the intersection between plastic, social inequity, and environmental injustice. Section 7 presents the Commission's findings and recommendations.

Plastics

Plastics are complex, highly heterogeneous, synthetic chemical materials. Over 98% of plastics are produced from fossil carbon- coal, oil and gas. Plastics are comprised of a carbon-based polymer backbone and thousands of additional chemicals that are incorporated into polymers to convey specific properties such as color, flexibility, stability, water repellence, flame retardation, and ultraviolet resistance. Many of these added chemicals are highly toxic. They include carcinogens, neurotoxicants and endocrine disruptors such as phthalates, bisphenols, per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants, and organophosphate flame retardants. They are integral components of plastic and are responsible for many of plastics' harms to human health and the environment.Global plastic production has increased almost exponentially since World War II, and in this time more than 8,300 megatons (Mt) of plastic have been manufactured. Annual production volume has grown from under 2 Mt in 1950 to 460 Mt in 2019, a 230-fold increase, and is on track to triple by 2060. More than half of all plastic ever made has been produced since 2002. Single-use plastics account for 35-40% of current plastic production and represent the most rapidly growing segment of plastic manufacture.Explosive recent growth in plastics production reflects a deliberate pivot by the integrated multinational fossil-carbon corporations that produce coal, oil and gas and that also manufacture plastics. These corporations are reducing their production of fossil fuels and increasing plastics manufacture. The two principal factors responsible for this pivot are decreasing global demand for carbon-based fuels due to increases in 'green' energy, and massive expansion of oil and gas production due to fracking.Plastic manufacture is energy-intensive and contributes significantly to climate change. At present, plastic production is responsible for an estimated 3.7% of global greenhouse gas emissions, more than the contribution of Brazil. This fraction is projected to increase to 4.5% by 2060 if current trends continue unchecked.

Plastic Life Cycle

The plastic life cycle has three phases: production, use, and disposal. In production, carbon feedstocks-coal, gas, and oil-are transformed through energy-intensive, catalytic processes into a vast array of products. Plastic use occurs in every aspect of modern life and results in widespread human exposure to the chemicals contained in plastic. Single-use plastics constitute the largest portion of current use, followed by synthetic fibers and construction.Plastic disposal is highly inefficient, with recovery and recycling rates below 10% globally. The result is that an estimated 22 Mt of plastic waste enters the environment each year, much of it single-use plastic and are added to the more than 6 gigatons of plastic waste that have accumulated since 1950. Strategies for disposal of plastic waste include controlled and uncontrolled landfilling, open burning, thermal conversion, and export. Vast quantities of plastic waste are exported each year from high-income to low-income countries, where it accumulates in landfills, pollutes air and water, degrades vital ecosystems, befouls beaches and estuaries, and harms human health-environmental injustice on a global scale. Plastic-laden e-waste is particularly problematic.

Environmental Findings

Plastics and plastic-associated chemicals are responsible for widespread pollution. They contaminate aquatic (marine and freshwater), terrestrial, and atmospheric environments globally. The ocean is the ultimate destination for much plastic, and plastics are found throughout the ocean, including coastal regions, the sea surface, the deep sea, and polar sea ice. Many plastics appear to resist breakdown in the ocean and could persist in the global environment for decades. Macro- and micro-plastic particles have been identified in hundreds of marine species in all major taxa, including species consumed by humans. Trophic transfer of microplastic particles and the chemicals within them has been demonstrated. Although microplastic particles themselves (>10 µm) appear not to undergo biomagnification, hydrophobic plastic-associated chemicals bioaccumulate in marine animals and biomagnify in marine food webs. The amounts and fates of smaller microplastic and nanoplastic particles (MNPs <10 µm) in aquatic environments are poorly understood, but the potential for harm is worrying given their mobility in biological systems. Adverse environmental impacts of plastic pollution occur at multiple levels from molecular and biochemical to population and ecosystem. MNP contamination of seafood results in direct, though not well quantified, human exposure to plastics and plastic-associated chemicals. Marine plastic pollution endangers the ocean ecosystems upon which all humanity depends for food, oxygen, livelihood, and well-being.

Human Health Findings

Coal miners, oil workers and gas field workers who extract fossil carbon feedstocks for plastic production suffer increased mortality from traumatic injury, coal workers' pneumoconiosis, silicosis, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer. Plastic production workers are at increased risk of leukemia, lymphoma, hepatic angiosarcoma, brain cancer, breast cancer, mesothelioma, neurotoxic injury, and decreased fertility. Workers producing plastic textiles die of bladder cancer, lung cancer, mesothelioma, and interstitial lung disease at increased rates. Plastic recycling workers have increased rates of cardiovascular disease, toxic metal poisoning, neuropathy, and lung cancer. Residents of "fenceline" communities adjacent to plastic production and waste disposal sites experience increased risks of premature birth, low birth weight, asthma, childhood leukemia, cardiovascular disease, chronic obstructive pulmonary disease, and lung cancer.During use and also in disposal, plastics release toxic chemicals including additives and residual monomers into the environment and into people. National biomonitoring surveys in the USA document population-wide exposures to these chemicals. Plastic additives disrupt endocrine function and increase risk for premature births, neurodevelopmental disorders, male reproductive birth defects, infertility, obesity, cardiovascular disease, renal disease, and cancers. Chemical-laden MNPs formed through the environmental degradation of plastic waste can enter living organisms, including humans. Emerging, albeit still incomplete evidence indicates that MNPs may cause toxicity due to their physical and toxicological effects as well as by acting as vectors that transport toxic chemicals and bacterial pathogens into tissues and cells.Infants in the womb and young children are two populations at particularly high risk of plastic-related health effects. Because of the exquisite sensitivity of early development to hazardous chemicals and children's unique patterns of exposure, plastic-associated exposures are linked to increased risks of prematurity, stillbirth, low birth weight, birth defects of the reproductive organs, neurodevelopmental impairment, impaired lung growth, and childhood cancer. Early-life exposures to plastic-associated chemicals also increase the risk of multiple non-communicable diseases later in life.

Economic Findings

Plastic's harms to human health result in significant economic costs. We estimate that in 2015 the health-related costs of plastic production exceeded $250 billion (2015 Int$) globally, and that in the USA alone the health costs of disease and disability caused by the plastic-associated chemicals PBDE, BPA and DEHP exceeded $920 billion (2015 Int$). Plastic production results in greenhouse gas (GHG) emissions equivalent to 1.96 gigatons of carbon dioxide (CO2e) annually. Using the US Environmental Protection Agency's (EPA) social cost of carbon metric, we estimate the annual costs of these GHG emissions to be $341 billion (2015 Int$).These costs, large as they are, almost certainly underestimate the full economic losses resulting from plastics' negative impacts on human health and the global environment. All of plastics' economic costs-and also its social costs-are externalized by the petrochemical and plastic manufacturing industry and are borne by citizens, taxpayers, and governments in countries around the world without compensation.

Social Justice Findings

The adverse effects of plastics and plastic pollution on human health, the economy and the environment are not evenly distributed. They disproportionately affect poor, disempowered, and marginalized populations such as workers, racial and ethnic minorities, "fenceline" communities, Indigenous groups, women, and children, all of whom had little to do with creating the current plastics crisis and lack the political influence or the resources to address it. Plastics' harmful impacts across its life cycle are most keenly felt in the Global South, in small island states, and in disenfranchised areas in the Global North. Social and environmental justice (SEJ) principles require reversal of these inequitable burdens to ensure that no group bears a disproportionate share of plastics' negative impacts and that those who benefit economically from plastic bear their fair share of its currently externalized costs.

Conclusions

It is now clear that current patterns of plastic production, use, and disposal are not sustainable and are responsible for significant harms to human health, the environment, and the economy as well as for deep societal injustices.The main driver of these worsening harms is an almost exponential and still accelerating increase in global plastic production. Plastics' harms are further magnified by low rates of recovery and recycling and by the long persistence of plastic waste in the environment.The thousands of chemicals in plastics-monomers, additives, processing agents, and non-intentionally added substances-include amongst their number known human carcinogens, endocrine disruptors, neurotoxicants, and persistent organic pollutants. These chemicals are responsible for many of plastics' known harms to human and planetary health. The chemicals leach out of plastics, enter the environment, cause pollution, and result in human exposure and disease. All efforts to reduce plastics' hazards must address the hazards of plastic-associated chemicals.

Recommendations

To protect human and planetary health, especially the health of vulnerable and at-risk populations, and put the world on track to end plastic pollution by 2040, this Commission supports urgent adoption by the world's nations of a strong and comprehensive Global Plastics Treaty in accord with the mandate set forth in the March 2022 resolution of the United Nations Environment Assembly (UNEA).International measures such as a Global Plastics Treaty are needed to curb plastic production and pollution, because the harms to human health and the environment caused by plastics, plastic-associated chemicals and plastic waste transcend national boundaries, are planetary in their scale, and have disproportionate impacts on the health and well-being of people in the world's poorest nations. Effective implementation of the Global Plastics Treaty will require that international action be coordinated and complemented by interventions at the national, regional, and local levels.This Commission urges that a cap on global plastic production with targets, timetables, and national contributions be a central provision of the Global Plastics Treaty. We recommend inclusion of the following additional provisions:The Treaty needs to extend beyond microplastics and marine litter to include all of the many thousands of chemicals incorporated into plastics.The Treaty needs to include a provision banning or severely restricting manufacture and use of unnecessary, avoidable, and problematic plastic items, especially single-use items such as manufactured plastic microbeads.The Treaty needs to include requirements on extended producer responsibility (EPR) that make fossil carbon producers, plastic producers, and the manufacturers of plastic products legally and financially responsible for the safety and end-of-life management of all the materials they produce and sell.The Treaty needs to mandate reductions in the chemical complexity of plastic products; health-protective standards for plastics and plastic additives; a requirement for use of sustainable non-toxic materials; full disclosure of all components; and traceability of components. International cooperation will be essential to implementing and enforcing these standards.The Treaty needs to include SEJ remedies at each stage of the plastic life cycle designed to fill gaps in community knowledge and advance both distributional and procedural equity.This Commission encourages inclusion in the Global Plastic Treaty of a provision calling for exploration of listing at least some plastic polymers as persistent organic pollutants (POPs) under the Stockholm Convention.This Commission encourages a strong interface between the Global Plastics Treaty and the Basel and London Conventions to enhance management of hazardous plastic waste and slow current massive exports of plastic waste into the world's least-developed countries.This Commission recommends the creation of a Permanent Science Policy Advisory Body to guide the Treaty's implementation. The main priorities of this Body would be to guide Member States and other stakeholders in evaluating which solutions are most effective in reducing plastic consumption, enhancing plastic waste recovery and recycling, and curbing the generation of plastic waste. This Body could also assess trade-offs among these solutions and evaluate safer alternatives to current plastics. It could monitor the transnational export of plastic waste. It could coordinate robust oceanic-, land-, and air-based MNP monitoring programs.This Commission recommends urgent investment by national governments in research into solutions to the global plastic crisis. This research will need to determine which solutions are most effective and cost-effective in the context of particular countries and assess the risks and benefits of proposed solutions. Oceanographic and environmental research is needed to better measure concentrations and impacts of plastics <10 µm and understand their distribution and fate in the global environment. Biomedical research is needed to elucidate the human health impacts of plastics, especially MNPs.

Summary

This Commission finds that plastics are both a boon to humanity and a stealth threat to human and planetary health. Plastics convey enormous benefits, but current linear patterns of plastic production, use, and disposal that pay little attention to sustainable design or safe materials and a near absence of recovery, reuse, and recycling are responsible for grave harms to health, widespread environmental damage, great economic costs, and deep societal injustices. These harms are rapidly worsening.While there remain gaps in knowledge about plastics' harms and uncertainties about their full magnitude, the evidence available today demonstrates unequivocally that these impacts are great and that they will increase in severity in the absence of urgent and effective intervention at global scale. Manufacture and use of essential plastics may continue. However, reckless increases in plastic production, and especially increases in the manufacture of an ever-increasing array of unnecessary single-use plastic products, need to be curbed.Global intervention against the plastic crisis is needed now because the costs of failure to act will be immense.

Prenatal exposure to air pollution and childhood internalizing problems: roles of shyness and anterior cingulate cortex activity

BACKGROUND

Prenatal exposure to air pollution increases the risk for psychiatric disorders characterized by internalizing problems. In this study, we examined the roles of shyness and anterior cingulate cortex (ACC) activity in the association between prenatal exposure to polycyclic aromatic hydrocarbons (PAH) and children's internalizing problems at 7-9 years old.

METHODS

Participants include 53 children (31 girls, 22 boys). Personal air monitoring was conducted over 48 continuous hours during the third trimester of pregnancy to measure 8 PAHs. Mothers reported children's shyness (Emotionality Activity Sociability Temperament Survey) at age 5 and internalizing problems (Child Behavior Checklist) at ages 7-9. ACC activity was measured by fMRI during the Simon Spatial Incompatibility task at ages 7-9.

RESULTS

Shyness mediated the association between prenatal PAH exposure and internalizing problems. Higher prenatal PAH exposure predicted increased shyness, which in turn predicted greater internalizing problems. Moreover, left ACC activity during the Simon task moderated the association between prenatal PAH exposure and internalizing problems. Prenatal PAH exposure predicted increased risk for internalizing problems only when children showed heightened left ACC activity during the resolution of cognitive conflict.

CONCLUSIONS

Our study innovatively synthesizes the fields of developmental psychology and environmental health science to offer new insights into the risk factors for anxiety disorders. Facilitating the development of healthy reactive and regulatory processes may improve the developmental outcomes for children highly exposed to air pollution.

A systematic review of evidence for maternal preconception exposure to outdoor air pollution on Children's health

The preconception period is a critical window for gametogenesis, therefore preconception exposure to air pollutants may have long-term effects on children. We systematically reviewed epidemiological evidence concerning the effects of preconception ambient air pollution exposure on children's health outcomes and identified research gaps for future investigations. We searched PubMed and Web of Science from journal inception up to October 2022 based on an established protocol (PROSPERO: CRD42022277608). We then identified 162 articles based on searching strategy, 22 of which met the inclusion criteria. Studies covered a wide range of health outcomes including birth defects, preterm birth, birthweight, respiratory outcomes, and developmental outcomes. Findings suggested that exposure to outdoor air pollutants during maternal preconception period were associated with various health outcomes, of which birth defects has the most consistent findings. A meta-analysis revealed that during 3-month preconception period, a 10 μg/m3 increase in PM10 and PM2.5 was associated with relative risk (RR) of birth defects of 1.06 (95% confidence interval (CI): 1.00, 1.02) and 1.14 (95% CI: 0.82, 1.59), respectively. Preterm birth, low birthweight, and autism have also been associated with maternal preconception exposure to PM2.5, PM10, O3 and SO2. However, the significance of associations and effect sizes varied substantially across studies, partly due to the heterogeneity in exposure and outcome assessments. Future studies should use more accurate exposure assessment methods to obtain individual-level exposures with high temporal resolution. This will allow the exploration of which specific time window (weeks or months) during the preconception period has the strongest effect. In future epidemiologic studies, integrating pathophysiologic biomarkers relevant to clinical outcomes may help improve the causal inference of associations between preconception exposure and health outcomes suggested by the current limited literature. Additionally, potential effects of paternal preconception exposure need to be studied.

Trimester-specific ambient PM2.5 exposures and risk of intellectual disability in Utah

Prenatal fine particulate matter (PM2.5) exposure is an understudied risk factor for neurodevelopmental outcomes, including intellectual disability (ID). Associations among prenatal exposures and neurodevelopmental outcomes may vary depending on the timing of exposure. Limited numbers of studies examining PM2.5 and neurodevelopmental outcomes have considered exposures occurring during the preconception period. To address these gaps, we conducted a case-control study of children born in Utah between 2002 and 2008 (n = 1032). Cases were identified using methods developed by the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring Network and matched with controls on birth year, sex, and birth county. We estimated the daily average PM2.5 concentration during a period spanning 12 weeks before the estimated conception date, as well as during each of the three trimesters at the maternal residential address listed on the child's birth certificate. In a multivariable model, the third (OR: 2.119, CI: 1.123-3.998, p = .021) and fourth (OR: 2.631, CI: 1.750-3.956, p < .001) quartiles for preconception average PM2.5 demonstrated significantly increased risk of ID relative to the first quartile. Second quartile preconception exposure was also associated with increased risk, though it did not reach significance (OR: 1.385, CI: 0.979-1.959, p = .07). The fourth quartile of first trimester average PM2.5 was positive and significant (OR: 2.278, CI: 1.522-3.411, p < .001); the third quartile was positive, but not significant (OR: 1.159, CI: 0.870-1.544, p = .312). Quartiles of second and third trimester were not associated with higher risk of ID. These findings from Utah, which were robust to a variety of sensitivity analyses, provide initial evidence that preconception and prenatal PM2.5 exposure may be associated with ID. Future studies are needed across other geographic locations and populations.

Environmental Toxicants and the Developing Brain

Early life represents the most rapid and foundational period of brain development and a time of vulnerability to environmental insults. Evidence indicates that greater exposure to ubiquitous toxicants like fine particulate matter (PM_2.5), manganese, and many phthalates is associated with altered developmental, physical health, and mental health trajectories across the lifespan. Whereas animal models offer evidence of their mechanistic effects on neurological development, there is little research that evaluates how these environmental toxicants are associated with human neurodevelopment using neuroimaging measures in infant and pediatric populations. This review provides an overview of 3 environmental toxicants of interest in neurodevelopment that are prevalent worldwide in the air, soil, food, water, and/or products of everyday life: fine particulate matter (PM_2.5), manganese, and phthalates. We summarize mechanistic evidence from animal models for their roles in neurodevelopment, highlight prior research that has examined these toxicants with pediatric developmental and psychiatric outcomes, and provide a narrative review of the limited number of studies that have examined these toxicants using neuroimaging with pediatric populations. We conclude with a discussion of suggested directions that will move this field forward, including the incorporation of environmental toxicant assessment in large, longitudinal, multimodal neuroimaging studies; the use of multidimensional data analysis strategies; and the importance of studying the combined effects of environmental and psychosocial stressors and buffers on neurodevelopment. Collectively, these strategies will improve ecological validity and our understanding of how environmental toxicants affect long-term sequelae via alterations to brain structure and function.

Prenatal exposure to PM2.5 and childhood cognition: Accounting for between-site heterogeneity in a pooled analysis of ECHO cohorts in the Northeastern United States

BACKGROUND

Emerging studies have investigated the adverse health effects of PM_2.5 using data from multiple cohorts, and results often are not generalizable across cohorts. We aimed to assess associations between prenatal PM_2.5 and childhood cognition in two U.S. cohorts while accounting for between-site heterogeneity.

METHODS

Analyses included 348 mother-child dyads enrolled in the dual site (New York City and Boston) PRogramming of Intergenerational Stress Mechanisms (PRISM) cohort and in the First Thousand Days of Life (FTDL) study (Northern Virginia) participating in the Environmental influences on Child Health Outcomes (ECHO) national consortium. Residential prenatal PM_2.5 exposure was estimated using a validated satellite-based model and childhood cognition was measured using the NIH Toolbox Cognition Battery at three to eight years of age. We used a log-linear model applied to contingency tables formed by cross-classifying covariates by site to examine between-site heterogeneity using 3^rd trimester PM_2.5 exposure, age-corrected cognition scores, and covariates potentially causing heterogeneities. Multivariable linear regression models informed by the combinability analysis were used to estimate the coefficients and 95% confidence intervals (CIs) for the association between 3^rd trimester PM_2.5 exposure and age-corrected cognition scores (mean = 100, SD = 15).

RESULTS

The log-linear model indicated that inter-study associations were similar between PRISM-NYC and FTDL, which were different from those in PRISM-Boston. Accordingly, we combined the data of PRISM-NYC and FTDL cohorts. We observed associations between 3^rd trimester PM_2.5 and cognition scores, findings were varying by site, childsex, and test. For example, a 1 μg/m³ increase of 3^rd trimester PM_2.5 was associated with -4.35 (95% CI = -8.73, -0.25) mean early childhood cognition scores in females in PRISM-Boston. In the pooled NYC + FTDL site, the association between PM_2.5 and childhood cognition may be modified by maternal education and urbanicity.

CONCLUSIONS

We found associations between prenatal PM_2.5 and impaired childhood cognition. Since multi-site analyses are increasingly conducted, our findings suggest the needed awareness of between-site heterogeneity.

Prenatal exposure to air pollution and maternal stress predict infant individual differences in reactivity and regulation and socioemotional development

BACKGROUND

Humans are ubiquitously exposed to air pollutants including polycyclic aromatic hydrocarbons (PAH). Although most studies of prenatal exposures have focused on psychopathology in childhood or adolescence, the effects of air pollutants on early emerging individual differences in reactivity and regulation are of growing concern. Our study is the first to report effects of prenatal exposure to PAH and maternal stress on infant reactivity and regulation.

METHODS

Participants included 153 infants (74 girls and 79 boys). Prenatal exposure to PAH was measured via personal air monitoring during the third trimester of pregnancy. Maternal perceived stress was measured via self-report. We assessed infant orienting/regulation (OR), surgency (SE), and negative affectivity (NA) at 4 months using the Infant Behavior Questionnaire. We measured infant socioemotional outcomes at 12 months using the Brief Infant-Toddler Social & Emotional Assessment Questionnaire.

RESULTS

Infants with higher prenatal PAH exposure and of mothers with higher stress had lower OR at 4 months, which predicted lower competence at 12 months. Infants with higher prenatal PAH exposure had lower SE at 4 months, which predicted more behavioral problems at 12 months. Prenatal exposure to PAH had no effects on infant NA at 4 months, although NA was associated with greater behavioral problems at 12 months.

CONCLUSIONS

Infant reactivity and regulation, as early makers of child psychopathology, can facilitate timely and targeted screening and possibly prevention of disorders caused, in part, by environmental pollution. A multifaceted approach to improve environmental quality and reduce psychosocial stress is necessary to improve the developmental outcomes of children and most specially children from disadvantaged communities that disproportionately experience these environmental exposures.

Maternal PM2.5 exposure during gestation and offspring neurodevelopment: Findings from a prospective birth cohort study

Emerging data have suggested the potential role of prenatal PM_2.5 exposure as a neurotoxin for offspring. However, the existing results are equivocal, and no study has examined the effects of complex chemical constituents of the particular matter on offspring neurodevelopment. Therefore, in a prospective birth cohort study conducted in Jiangsu, China, we aimed to investigate the association between prenatal exposure to PM_2.5 and the neurodevelopment in infants, and further assess the effects of specific chemical constituents of PM_2.5. A total of 1531 children who had available data on daily prenatal PM_2.5 exposure and completed assessment on neurodevelopment at 1 year old were enrolled. We used the high-performance machine-learning model to estimate daily PM_2.5 exposure concentrations at 1 km × 1 km spatial resolution. The combined geospatial-statistical model was applied to evaluate average concentrations of six chemical constituents [organic matter (OM), black carbon (BC), sulfate (SO₄^2-), nitrate (NO₃^-), ammonium (NH₄⁺), and soil dust (Dust)]. The neurodevelopment of children was assessed using Bayley-III Screening Test. After adjusting for confounding factors, the risk of non-optimal gross motor development increased by 31 % for every 10 μg/m³ increase in average PM_2.5 exposure during gestation (aRR: 1.31; 95 % CI: 1.04, 1.64). Further analysis of PM_2.5 constituents showed that prenatally exposed to high SO₄^2- was associated with the risk of non-optimal gross motor development (aRR: 1.40; 95 % CI: 1.08, 1.81). Null associations were observed for the rest four neurodevelopment domains. Collectively, our study suggested that prenatal exposure to PM_2.5, particularly with high SO₄^2- concentration, was associated with children's non-optimal gross motor development at 1 year old. The short- and long-term influences of perinatal PM_2.5 exposure on children's neurodevelopment warrant further investigation.

In-utero exposure to indoor air pollution or tobacco smoke and cognitive development in a South African birth cohort study

BACKGROUND AND AIMS

There is increasing evidence indicating that air pollution exposure is associated with neuronal damage. Since pregnancy is a critical window of vulnerability, air pollution exposure during this period could have adverse effects on neurodevelopment. This study aims 1) to analyze associations of prenatal exposure to indoor air pollution (particulate matter with diameters ≤10 μm, PM10) and tobacco smoke with neurodevelopment and 2) to determine whether these associations are mediated by deviations of epigenetic gestational age from chronological gestational age (ΔGA).

METHODS

Data of 734 children from the South African Drakenstein Child Health Study were analyzed. Prenatal PM10 exposure was measured using devices placed in the families' homes. Maternal smoking during pregnancy was determined by maternal urine cotinine measures. The Bayley Scales of Infant and Toddler Development III (BSID-III) was used to measure cognition, language and motor development and adaptive behavior at two years of age. Linear regression models adjusted for maternal age, gestational age, sex of child, ancestry, birth weight/length, and socioeconomic status were used to explore associations between air pollutants and BSID-III scores. A mediation analysis was conducted to analyze if these associations were mediated by ΔGA using DNA methylation measurements from cord blood.

RESULTS

An increase of one interquartile range in natural-log transformed PM10 (lnPM10; 1.58 μg/m3) was significantly associated with lower composite scores in cognition, language, and adaptive behavior sub-scores (composite score β-estimate [95%-confidence interval]: -0.950 [-1.821, -0.120]). Maternal smoking was significantly associated with lower adaptive behavior scores (-3.386 [-5.632, -1.139]). Associations were not significantly mediated by ΔGA (e.g., for PM10 and cognition, proportion mediated [p-value]: 4% [0.52]).

CONCLUSION

We found an association of prenatal exposure to indoor air pollution (PM10) and tobacco smoke on neurodevelopment at two years of age, particularly cognition, language, and adaptive behavior. Further research is needed to understand underlying biological mediators.

A replicable strategy for mapping air pollution's community-level health impacts and catalyzing prevention

BACKGROUND

Air pollution was responsible for an estimated 6.7 million deaths globally in 2019 and 197,000 deaths in the United States. Fossil fuel combustion is the major source.

HYPOTHESIS

Mapping air pollution's health impacts at the community level using publicly available data and open-source software will provide a replicable strategy for catalyzing pollution prevention.

METHODS

Using EPA's Environmental Benefits Mapping and Analysis (BenMAP-CE) software and state data, we quantified the effects of airborne fine particulate matter (PM_2.5) pollution on disease, death and children's cognitive function (IQ Loss) in each city and town in Massachusetts. To develop a first-order estimate of PM_2.5 pollution's impact on child IQ, we derived a concentration-response coefficient through literature review.

FINDINGS

The annual mean PM_2.5 concentration in Massachusetts in 2019 was 6.3 μg/M³, a level below EPA's standard of 12 μg/M³ and above WHO's guideline of 5 μg/M³. In adults, PM_2.5 pollution was responsible for an estimated 2780 (Confidence Interval [CI] 2726 - 2853) deaths: 1677 (CI, 1346 - 1926) from cardiovascular disease, 2185 (CI, 941-3409) from lung cancer, 200 (CI, 66-316) from stroke, and 343 (CI, 222-458) from chronic respiratory disease. In children, PM_2.5 pollution was responsible for 308 (CI, 105-471) low-weight births, 15,386 (CJ, 5433-23,483) asthma cases, and a provisionally estimated loss of nearly 2 million Performance IQ points; IQ loss impairs children's school performance, reduces graduation rates and decreases lifetime earnings. Air-pollution-related disease, death and IQ loss were most severe in low-income, minority communities, but occurred in every city and town in Massachusetts regardless of location, demographics or median family income.

CONCLUSION

Disease, death and IQ loss occur at air pollution exposure levels below current EPA standards. Prevention of disease and premature death and preservation of children's cognitive function will require that EPA air quality standards be tightened. Enduring prevention will require government-incentivized transition to renewable energy coupled with phase-outs of subsidies and tax breaks for fossil fuels. Highly localized information on air pollution's impacts on health and on children's cognitive function has potential to catalyze pollution prevention.

Combined toxicity of air pollutants related to e-waste on inflammatory cytokines linked with neurotransmitters and pediatric behavioral problems

E-waste usually refers to the discarded electrical or electronic equipment that is no longer used. Informal e-waste recycling methods, such as burning, roasting, acid leaching, and shredding, had resulted in serious air pollution, which is a prominent risk factor for children's health. However, the combined toxicity of air pollutants on children's behavioral health remains unclear. This study collected data on air pollution exposure, calculated the average daily dose (ADD) based on these air pollutants for children in Guiyu (e-waste group, n = 112) and Haojiang (reference group, n = 101), then assessed children's behavioral health using the Strengths and Difficulties Questionnaire (SDQ), and further estimated the associations of ADD, inflammatory cytokines, neurotransmitters, and children's behavioral problems. Compared with Haojiang, Guiyu has poorer air quality and higher levels of ADD, inflammatory cytokines (such as IL-1β, IL-6, and TNF-α), neurotransmitters (such as DA and SP), and SDQ scores, but lower levels of serum neuropeptide Y (NPY) levels. Spearman correlation analyses indicated that there were significant relationships among inflammatory cytokines, neurotransmitters, and behavioral scores. Multiple linear regression analyses showed that each unit increase in ADD was associated with serum levels of DA and SP, the serum NPY subsequently changed by B (95% CI): 0.99 (0.14, 1.84) nmol/L, 0.25 (0.08, 0.42) ng/mL, and - 0.16 (-0.26, -0.05) ng/mL, respectively. After adjustment for confounders, logistic regression analyses suggested that with each one-fold increase in ADD was associated with the risk of emotional symptoms [OR (95% CI): 18.15 (2.72, 121.06)], hyperactivity-inattention [13.64 (2.28, 81.65)] and total difficulties [8.90 (1.60, 49.35)] and prosocial behavior [- 7.32 (-44.37, -1.21)]. Taken together, this study demonstrates that combined exposure to air pollutants may alter the levels of inflammatory cytokines and serum neurotransmitter to subsequently impact behavioral health in children.

Exposure to traffic-related air pollution and noise during pregnancy and childhood, and functional brain connectivity in preadolescents

BACKGROUND

The amount of people affected by traffic-related air pollution and noise is continuously increasing, but limited research has been conducted on the association between these environmental exposures and functional brain connectivity in children.

OBJECTIVE

This exploratory study aimed to analyze the associations between the exposure to traffic-related air pollution and noise during pregnancy and childhood, and functional brain connectivity amongst a wide-swath of brain areas in preadolescents from 9 to 12 years of age.

METHODS

We used data of 2,197 children from the Generation R Study. Land use regression models were applied to estimate nitrogen oxides and particulate matter levels at participant's homes for several time periods: pregnancy, birth to 3 years, 3 to 6 years, and 6 years of age to the age at magnetic resonance imaging (MRI) assessment. Existing noise maps were used to estimate road traffic noise exposure at participant's homes for the same time periods. Resting-state functional MRI was obtained at 9-12 years of age. Pair-wise correlation coefficients of the blood-oxygen-level-dependent signals between 380 brain areas were calculated. Linear regressions were run and corrected for multiple testing.

RESULTS

Preadolescents exposed to higher levels of NO₂, NO_x, and PM_2.5 absorbance, from birth to 3 years, and from 3 to 6 years of age showed higher correlation coefficients among several brain regions (e.g. from 0.16 to 0.19 higher correlation coefficient related to PM_2.5 absorbance exposure, depending on the brain connection). Overall, most identified associations were between brain regions of the task positive and task negative networks, and were mainly inter-network (20 of 26). Slightly more than half of the connections were intra-hemispheric (14 of 26), predominantly in the right hemisphere. Road traffic noise was not associated with functional brain connectivity.

CONCLUSIONS

This exploratory study found that exposure to traffic-related air pollution during the first years of life was related to higher functional brain connectivity predominantly in brain areas located in the task positive and task negative networks, in preadolescents from 9 to 12 years of age. These results could be an indicator of differential functional connectivity in children exposed to higher levels of air pollution.

Associations of Pre- and Postnatal Air Pollution Exposures with Child Behavioral Problems and Cognitive Performance: A U.S. Multi-Cohort Study

BACKGROUND

Population studies support the adverse associations of air pollution exposures with child behavioral functioning and cognitive performance, but few studies have used spatiotemporally resolved pollutant assessments.

OBJECTIVES

We investigated these associations using more refined exposure assessments in 1,967 mother-child dyads from three U.S. pregnancy cohorts in six cities in the ECHO-PATHWAYS Consortium.

METHODS

Pre- and postnatal nitrogen dioxide (NO2) and particulate matter (PM) ≤2.5μm in aerodynamic diameter (PM2.5) exposures were derived from an advanced spatiotemporal model. Child behavior was reported as Total Problems raw score using the Child Behavior Checklist at age 4-6 y. Child cognition was assessed using cohort-specific cognitive performance scales and quantified as the Full-Scale Intelligence Quotient (IQ). We fitted multivariate linear regression models that were adjusted for sociodemographic, behavioral, and psychological factors to estimate associations per 2-unit increase in pollutant in each exposure window and examined modification by child sex. Identified critical windows were further verified by distributed lag models (DLMs).

RESULTS

Mean NO2 and PM2.5 ranged from 8.4 to 9.0 ppb and 8.4 to 9.1 μg/m3, respectively, across pre- and postnatal windows. Average child Total Problems score and IQ were 22.7 [standard deviation (SD): 18.5] and 102.6 (SD: 15.3), respectively. Children with higher prenatal NO2 exposures were likely to have more behavioral problems [β: 1.24; 95% confidence interval (CI): 0.39, 2.08; per 2 ppb NO2], particularly NO2 in the first and second trimester. Each 2-μg/m3 increase in PM2.5 at age 2-4 y was associated with a 3.59 unit (95% CI: 0.35, 6.84) higher Total Problems score and a 2.63 point (95% CI: -5.08, -0.17) lower IQ. The associations between PM2.5 and Total Problems score were generally stronger in girls. Most predefined windows identified were not confirmed by DLMs.

DISCUSSION

Our study extends earlier findings that have raised concerns about impaired behavioral functioning and cognitive performance in children exposed to NO2 and PM2.5 in utero and in early life. https://doi.org/10.1289/EHP10248.

Multiomics to elucidate inflammatory bowel disease risk factors and pathways

Inflammatory bowel disease (IBD) is an immune-mediated disease of the intestinal tract, with complex pathophysiology involving genetic, environmental, microbiome, immunological and potentially other factors. Epidemiological data have provided important insights into risk factors associated with IBD, but are limited by confounding, biases and data quality, especially when pertaining to risk factors in early life. Multiomics platforms provide granular high-throughput data on numerous variables simultaneously and can be leveraged to characterize molecular pathways and risk factors for chronic diseases, such as IBD. Herein, we describe omics platforms that can advance our understanding of IBD risk factors and pathways, and available omics data on IBD and other relevant diseases. We highlight knowledge gaps and emphasize the importance of birth, at-risk and pre-diagnostic cohorts, and neonatal blood spots in omics analyses in IBD. Finally, we discuss network analysis, a powerful bioinformatics tool to assemble high-throughput data and derive clinical relevance.

Convergent neural correlates of prenatal exposure to air pollution and behavioral phenotypes of risk for internalizing and externalizing problems: Potential biological and cognitive pathways

Humans are ubiquitously exposed to neurotoxicants in air pollution, causing increased risk for psychiatric outcomes. Effects of prenatal exposure to air pollution on early emerging behavioral phenotypes that increase risk of psychopathology remain understudied. We review animal models that represent analogues of human behavioral phenotypes that are risk markers for internalizing and externalizing problems (behavioral inhibition, behavioral exuberance, irritability), and identify commonalities among the neural mechanisms underlying these behavioral phenotypes and the neural targets of three types of air pollutants (polycyclic aromatic hydrocarbons, traffic-related air pollutants, fine particulate matter < 2.5 µm). We conclude that prenatal exposure to air pollutants increases risk for behavioral inhibition and irritability through distinct mechanisms, including altered dopaminergic signaling and hippocampal morphology, neuroinflammation, and decreased brain-derived neurotrophic factor expression. Future studies should investigate these effects in human longitudinal studies incorporating complex exposure measurement methods, neuroimaging, and behavioral characterization of temperament phenotypes and neurocognitive processing to facilitate efforts aimed at improving long-lasting developmental benefits for children, particularly those living in areas with high levels of exposure.

Prenatal Exposure to Air Pollution and Early Life Stress Effects on Hippocampal Subregional Volumes and Associations with Visual-Spatial Reasoning

Background

Children from economically distressed families and neighborhoods are at risk for stress and pollution exposure and potential neurotoxic sequelae. We examine dimensions of early-life stress affecting hippocampal volumes, how prenatal exposure to air pollution might magnify these effects, and associations between hippocampal volumes and visuospatial reasoning.

Methods

Fifty-three Hispanic/Latinx and/or Black children of ages 7 to 9 years were recruited from a longitudinal birth cohort for magnetic resonance imaging and cognitive assessment. Exposure to airborne polycyclic aromatic hydrocarbons was measured during the third trimester of pregnancy. Maternal report of psychosocial stress was collected at child age 5 and served as measures of early-life stress. Whole hippocampus and subfield volumes were extracted using FreeSurfer. Wechsler performance IQ measured visuospatial reasoning.

Results

Maternal perceived stress associated with smaller right hippocampal volume among their children (B = −0.57, t₃₄ = −3.05, 95% CI, −0.95 to −0.19). Prenatal polycyclic aromatic hydrocarbon moderated the association between maternal perceived stress and right CA1, CA3, and CA4/dentate gyrus volumes (B ≥ 0.68, t₃₃ ≥ 2.17) such that higher prenatal polycyclic aromatic hydrocarbon exposure magnified negative associations between stress and volume, whereas this was buffered at lower exposure. Right CA3 and CA4/dentate gyrus volumes (B ≥ 0.35, t₃₃ > 2.16) were associated with greater performance IQ.

Conclusions

Prenatal and early-life exposures to chemical and social stressors are likely compounding. Socioeconomic deprivation and disparities increase risk of these exposures that exert critical neurobiological effects. Developing deeper understandings of these complex interactions will facilitate more focused public health strategies to protect and foster the development of children at greatest risk of mental and physical effects associated with poverty.

Air pollution and mental health: associations, mechanisms and methods

PURPOSE OF REVIEW

There is increasing interest in the links between exposure to air pollution and a range of health outcomes. The association with mental health however is much less established. This article reviews developments in the field over the past 12 months, highlighting the evidence for causation, associations between multiple air pollutants and mental health outcomes, and assesses the challenges of researching this topic.

RECENT FINDINGS

Increasingly rigorous methods are being applied to the investigation of a broader range of mental health outcomes. These methods include basic science, neuroimaging, and observational studies representing diverse geographical locations. Cohort studies with linked high-resolution air pollutant exposure data are common, facilitating advanced analytic methods. To date, meta-analyses have demonstrated small and significant positive associations between long-term exposure to fine particulate matter and depressive symptoms and cognitive decline. Methodological complexities in measuring exposure and outcome pose ongoing difficulties for the field.

SUMMARY

Literature on this topic has recently seen an appreciable expansion. Work that better estimates daily exposure, controls for complex confounders, and is driven by hypotheses founded in candidate causal mechanisms would help clarify associations, and inform targeted interventions and policymakers.

Prenatal exposure to air pollution and neurodevelopmental delay in children: A birth cohort study in Foshan, China

BACKGROUND

Prenatal exposure to air pollution may have adverse effects on neurodevelopment in children, but epidemiological evidence remains inconclusive.

OBJECTIVE

To investigate the associations between prenatal air pollution exposure and neurodevelopmental delay.

METHODS

We conducted a birth cohort study based on pregnancy and birth registry in Foshan, China. Exposure to particulate matter of aerodynamic diameter < 1 μm, 2.5 μm, 10 μm (PM₁, PM_2.5, PM₁₀), nitrogen dioxide (NO₂) and sulfur dioxide (SO₂) over pregnancy (trimester 1, 2, 3 and entire pregnancy) was estimated at each woman's residential address using spatial-temporal models. Neurodevelopmental assessment was performed by pediatricians using a five-domain scale and developmental quotient (DQ) was calculated as a global measure. Logistic regression models were used to investigate the associations between prenatal air pollution exposure and neurodevelopmental delay (DQ < 75) with adjustment for potential confounders.

RESULTS

We included 15,778 child-mother pairs in this analysis, including 1013 children with neurodevelopmental delay. We observed positive associations between prenatal exposure to air pollution and higher risk of neurodevelopmental delay in children. The adjusted odds ratios (ORs) per 10 μg/m³ elevation in PM₁, PM_2.5, PM₁₀, NO₂ and SO₂ in entire pregnancy were 1.12 [95% confidence interval (CI): 1.01, 1.25], 1.15 (95% CI: 1.03, 1.29), 1.12 (95% CI: 1.02, 1.24), 1.06 (95% CI: 0.94, 1.19) and 1.58 (95% CI: 1.11, 2.23), respectively. The associations were more robust for trimester 1 and trimester 2, especially trimester 1.

CONCLUSIONS

Exposure to air pollution during pregnancy, especially early-to-mid pregnancy, was associated with increased risk of neurodevelopmental delay in young children, indicating its adverse neurodevelopmental effects in early-life stage.

Effects of prenatal exposures to air sulfur dioxide/nitrogen dioxide on toddler neurodevelopment and effect modification by ambient temperature

Emerging evidence suggests that prenatal exposure to ambient SO2 or NO2 induces fetal brain-damage. However, effects of prenatal exposure to SO2 or NO2 on toddler neurodevelopment and the effect-modification by ambient temperature remain unclear. Therefore, a prospective birth-cohort study was conducted from 2010 to 2012 in Shanghai, and 225 mother-child pairs were followed-up from mid-to-late pregnancy until 24-36 months postpartum. During the whole pregnancy, daily SO2/NO2 and temperature levels were obtained for each woman. Gesell-Development-Schedule was used to assess toddler neurodevelopment in the domains of gross-motor, fine-motor, adaptive-behavior, language and social-behavior. Distributed-lag-nonlinear-models simultaneously accounting for exposure-response and lag-response associations were applied to assess the impacts of prenatal SO2/NO2 exposure on neurodevelopment. Each 10-μg/m3 increase in weekly average SO2 concentrations had adverse associations with gross-motor in gestational-weeks 1-6, with adaptive-behavior in weeks 26-30, and with language in weeks 30-36 (developmental-quotient changes: - 1.17% to - 0.12%, P-values < 0.05). Each 10-μg/m3 increase in weekly average NO2 concentrations had adverse associations with gross-motor in gestational-weeks 33-36, with fine-motor in weeks 26-36 and with social-behavior in weeks 31-36 (developmental-quotient changes: - 0.91% to - 0.20%, P-values < 0.05). The cumulative effects for the whole pregnancy showed that each 10-μg/m3 increase in SO2 induced significant deficits in gross-motor and adaptive-behavior (developmental-quotient changes: - 4.71% and - 4.06%, respectively, P < 0.05). We found prenatal cumulative SO2 exposure induced more deficits in low temperature in language and adaptive-behavior than in high/moderate temperature. Thus, prenatal ambient SO2/NO2 exposure in specific time-windows (1st and 3rd trimesters for SO2; 3rd trimester for NO2) could impair toddler neurodevelopment and low temperature may aggravate the SO2-induced neurotoxicity.

Prenatal Exposure to Per- and Polyfluoroalkyl Substances and Facial Features at 5 Years of Age: A Study from the Danish National Birth Cohort

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are widespread persistent pollutants. Evidence regarding neurodevelopmental effects of PFAS have been mixed. The relation between PFAS exposure and anatomical markers that have been suggested to correlate with fetal brain development have not been studied.

OBJECTIVES

We investigated the association between prenatal PFAS exposures and three craniofacial features in children measured at 5 years of age.

METHODS

Measures of palpebral fissure length (PFL), philtrum groove, and upper-lip thickness were generated from standardized digital facial photographs from 656 children in the Danish National Birth Cohort. PFL was classified into two groups (shorter; normal), and the philtrum (grooved; smooth; normal) and upper-lip (thick; thin; normal) measures into three groups each. Six PFAS were measured in maternal plasma (median=8 gestational wk). Multinomial logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for each facial feature using the normal group as the reference according to log2-PFAS concentration (in nanograms per milliliter) or PFAS tertiles, adjusting for potential confounders, including maternal alcohol intake and smoking. Stratified analyses by maternal alcohol intake or child's sex were performed.

RESULTS

Prenatal exposure to each PFAS was associated with elevated odds for a shorter PFL, with the strongest association observed for perfluorodecanoic acid (PFDA; per doubling OR=2.02; 95% CI: 1.11, 3.70). Some nonlinear associations were found for philtrum measures: the second tertile of PFDA and perfluorononanoic acid were associated with grooved philtrum, whereas the second tertile of perfluoroheptane sulfonate with smooth philtrum. The associations between PFAS exposure and a shorter PFL were stronger among mothers who consumed alcohol in the first trimester, some sex-specific associations were noted for philtrum and upper-lip measures.

DISCUSSION

Prenatal PFAS exposures might influence fetal craniofacial development. A larger study is needed to replicate the potential modifying effects observed for alcohol exposure and to clarify whether associations of craniofacial markers observed reflect specific neurologic deficits. https://doi.org/10.1289/EHP9478.

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

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.

Global Burden of Disease from Major Air Pollution Sources (GBD MAPS): A Global Approach

Ambient fine particulate matter (particles <2.5 μm in aerodynamic diameter [PM2.5]) is the world's leading environmental health risk factor. Reducing the PM2.5 disease burden requires specific strategies that target dominant sources across multiple spatial scales. The Global Burden of Disease from Major Air Pollution Sources (GBD MAPS) project provides a contemporary and comprehensive evaluation of contributions to the ambient PM2.5 disease burden from source sectors and fuels across 21 regions, 204 countries, and 200 subnational areas. We first derived quantitative contributions from 24 emission sensitivity simulations using an updated global atmospheric chemistry-transport model, input with a newly developed detailed anthropogenic emissions dataset that includes emissions specific to source sector and fuels. These simulation results were integrated with newly available high-resolution satellite-derived PM2.5 exposure estimates and disease-specific concentration-response relationships consistent with the GBD project to quantify contributions of specific source sector and fuel to the ambient PM2.5 disease burden across all regions, countries, and subnational areas. To improve the transparency and reproducibility of this and future work, we publicly provided the global atmospheric chemistry-transport model source code, emissions dataset and emissions model source code, analysis scripts, and source sensitivity results, and further described the emissions dataset and source contribution results in two publications.

We found that nearly 1.05 million (95% uncertainty interval [UI]: 0.74-1.36 million) deaths worldwide (27.3% of the total mortality attributable to PM2.5) would be avoidable by eliminating fossil fuel combustion, with coal contributing over half of that burden. Residential (19.2%; 736,000 deaths [95% UI: 521,000-955,000]), industrial (11.7%; 448,000 deaths [95% UI: 318,000-582,000]), and energy (10.2%; 391,000 deaths [95% UI: 277,000-507,000]) sector emissions are among the dominant global sources Uncertainty in these estimates reflects those of the input datasets. Regions with the largest anthropogenic contributions generally have the highest numbers of attributable deaths, which clearly demonstrates the importance of reducing these emissions to realize reductions in global air pollution and its disease burden.

Prenatal Particulate Matter Exposure Is Associated with Saliva DNA Methylation at Age 15: Applying Cumulative DNA Methylation Scores as an Exposure Biomarker

Exposure in utero to particulate matter (PM2.5 and PM10) is associated with maladaptive health outcomes. Although exposure to prenatal PM2.5 and PM10 has cord blood DNA methylation signatures at birth, signature persistence into childhood and saliva cross-tissue applicability has not been tested. In the Fragile Families and Child Wellbeing Study, a United States 20-city birth cohort, average residential PM2.5 and PM10 during the three months prior to birth was estimated using air quality monitors with inverse distance weighting. Saliva DNA methylation at ages 9 (n = 749) and 15 (n = 793) was measured using the Illumina HumanMethylation 450 k BeadArray. Cumulative DNA methylation scores for particulate matter were estimated by weighting participant DNA methylation at each site by independent meta-analysis effect estimates and standardizing the sums. Using a mixed-effects regression analysis, we tested the associations between cumulative DNA methylation scores at ages 9 and 15 and PM exposure during pregnancy, adjusted for child sex, age, race/ethnicity, maternal income-to-needs ratio, nonmartial birth status, and saliva cell-type proportions. Our study sample was 50.5% male, 56.3% non-Hispanic Black, and 19.8% Hispanic, with a median income-to-needs ratio of 1.4. Mean exposure levels for PM2.5 were 27.9 μg/m³/day (standard deviation: 7.0; 23.7% of observations exceeded safety standards) and for PM10 were 15.0 μg/m³/day (standard deviation: 3.1). An interquartile range increase in PM2.5 exposure (10.73 μg/m³/day) was associated with a −0.0287 standard deviation lower cumulative DNA methylation score for PM2.5 (95% CI: −0.0732, 0.0158, p = 0.20) across all participants. An interquartile range increase in PM10 exposure (3.20 μg/m³/day) was associated with a −0.1472 standard deviation lower cumulative DNA methylation score for PM10 (95% CI: −0.3038, 0.0095, p = 0.06) across all participants. The PM10 findings were driven by the age 15 subset where an interquartile range increase in PM10 exposure was associated with a −0.024 standard deviation lower cumulative DNA methylation score for PM10 (95% CI: −0.043, −0.005, p = 0.012). Findings were robust to adjustment for PM exposure at ages 1 and 3. In utero PM10-associated DNA methylation differences were identified at age 15 in saliva. Benchmarking the timing and cell-type generalizability is critical for epigenetic exposure biomarker assessment.