Faculty Bibliography

BACKGROUND/UNASSIGNED:Organophosphate ester flame retardants and plasticizers (OPEs) have myriad uses in industry and consumer products. Increasing human exposure to OPEs has raised concerns about their potential effects on child neurodevelopment during pregnancy. OBJECTIVE/UNASSIGNED:We investigated whether OPE urinary concentrations during pregnancy were associated with child autism-related outcomes. METHODS/UNASSIGNED:We included 4159 mother-child pairs from 15 cohorts in the NIH Environmental influences on Child Health Outcomes (ECHO) Consortium, with children born from 2006-2020 (median age [interquartile range]: 6 [4,10] years). Nine OPE biomarkers were measured in urine samples collected mid- to late pregnancy. Dilution-adjusted biomarkers were modeled continuously, categorically (high [> median], moderate [≤ median], non-detect), or as detect/non-detect depending on their detection frequency. We assessed child autism-related traits via a) parent report on the Social Responsiveness Scale (SRS) and b) clinical autism diagnosis. We examined associations of OPEs with child outcomes, including modification by child sex, using generalized estimating equations to account for clustering by ECHO cohort. RESULTS/UNASSIGNED:Compared with non-detectable concentrations, high exposure to bis(butoxyethyl) phosphate (BBOEP) was associated with higher autistic trait scores (adj-β 0.97, 95% confidence interval [CI]: 0.42, 1.52) and greater odds of autism diagnosis (adjusted odds ratio [adj-OR]: 1.27, 95% CI: 1.07, 1.50). Bis(1-chloro-2-propyl) phosphate (BCPP) showed associations with autistic trait scores (BCPP adj-β for high exposure vs. non-detect: 0.34, 95% CI: -0.46, 1.13; BCPP adj-β for moderate exposure vs. non-detect: 0.72, 95% CI: 0.24, 1.20). High exposure to bis(2-chloroethyl) phosphate (BCETP) was associated with lower odds of autism diagnosis (adj-OR: 0.76, 95% CI: 0.60, 0.95). Other OPEs showed no associations in adjusted models. Associations between BBOEP and higher autistic trait scores were stronger in males than females. DISCUSSION/UNASSIGNED:Prenatal exposure to OPEs, specifically BCPP and BBOEP, may be associated with higher risk of autism diagnosis and related traits in childhood. https://doi.org/10.1289/EHP16177.

BACKGROUND/UNASSIGNED:Maternal sustained smoking during pregnancy is associated with thousands of differentially methylated CpGs in newborns, but impacts of other prenatal tobacco smoking exposures remain unclear. OBJECTIVE/UNASSIGNED:To identify differential DNA methylation in newborns from maternal sustained smoking and less studied prenatal smoking exposures (i.e., maternal exposure to secondhand smoke [SHS] exposure during pregnancy, maternal quitting before pregnancy, paternal smoking around conception, paternal quitting before pregnancy). METHODS/UNASSIGNED:We conducted a large meta-analysis of prenatal tobacco smoking exposures and epigenome-wide newborn blood DNA methylation through the Pregnancy And Childhood Epigenetics Consortium (PACE). Across 19 cohorts, 11,175 parent-newborn pairs contributed information on at least one prenatal smoking exposure, mostly from questionnaires. Maternal blood or urine cotinine measurements, available in a few studies, provided objective data on maternal SHS and smoking during pregnancy. Primary analyses used Illumina450K methylation data; secondary analyses in 5 cohorts examined CpGs unique to the EPIC array. RESULTS/UNASSIGNED:) was associated with paternal former smoking. Forty-one novel genes were identified using maternal cotinine measurements compared to questionnaire. In EPIC unique analyses (n=3,415), differential methylation was observed with maternal sustained smoking (211 CpGs), maternal SHS (5 CpGs), and paternal former smoking (4 CpGs). Smoking-associated CpGs in blood were strongly enriched for functional elements across multiple tissues. CONCLUSIONS/UNASSIGNED:Maternal sustained smoking has the largest impact on newborn DNA methylation, suggesting a strong influence of the intrauterine environment. We observed minimal impacts for less studied exposures including SHS, maternal former smoking and paternal smoking. https://doi.org/10.1289/EHP16303.

UNLABELLED:Exposures to phthalates and synthetic phenols are common among expectant mothers in the US. Previous studies on the neurotoxicity of these compounds have primarily assessed the effects of individual compounds on child behavior, but have not assessed potential combined effects of these substances. We assessed associations between prenatal exposure to a mixture of phthalates and phenols with behavioral problems among preschool-age children participating in the Environmental influences on Child Health Outcome (ECHO) Program. The study sample included 878 mother-child pairs from three cohorts with data on urinary concentrations of 10 phenols and 11 phthalate metabolites during pregnancy, along with caregiver reported Child Behavioral Checklist Ages 1½ to 5 (CBCL) data. Using covariate-adjusted weighted quantile sum (WQS) regression, we estimated associations between the phenol - phthalate mixture and CBCL behavioral scales T-scores. We fitted additional models stratified by sex due to previous reports of sex-specific associations. No statistically significant associations were observed in the overall sample when both male and female children were combined. However, in males, a quintile increase in the WQS index was associated with a 0.04 (95% CI: 0.00; 0.08) higher T-score of externalizing problems. The major contributors to this mixture effect were butylparaben (with a weight of 21%), benzophenone-3 (15%) and MCNP (11%). Conversely, in females, significant negative associations were observed between the WQS index with the total behavioral problems scale (beta = −0.05, 95% CI: −0.09; −0.01), externalizing problems (beta = −0.06, 95% CI = −0.10; −0.02) and internalizing problems (beta = −0.04, 95% CI: −0.08; −0.00). CONCLUSION::Our findings suggest that exposure to synthetic phenols and phthalate metabolite mixtures during pregnancy may impact childhood externalizing behavior with distinct associations in males and females. These findings contribute to the existing evidence on the combined effects of these compounds during development, emphasizing the need for further research on the combined effects of these mixtures.

IMPORTANCE/UNASSIGNED:Identifying atypical body mass index (BMI) trajectories in children and understanding associated, modifiable early-life factors may help prevent childhood obesity. OBJECTIVE/UNASSIGNED:To characterize multiphase BMI trajectories in children and identify associated modifiable early-life factors. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This cohort study included longitudinal data obtained from January 1997 to June 2024, from the Environmental influences on Child Health Outcomes (ECHO) cohort, which included children aged 1 to 9 years with 4 or more weight and height assessments. Analyses were conducted from January to June 2024. EXPOSURES/UNASSIGNED:Prenatal exposure to substances and stress (smoking, alcohol, depression, anxiety), maternal characteristics (prepregnancy BMI, gestational weight gain), child characteristics (preterm birth, birth weight, breastfeeding), and demographic covariates. MAIN OUTCOMES AND MEASURES/UNASSIGNED:BMI (calculated as weight in kilograms divided by length in meters squared for children aged 1 and 2 years and as weight in kilograms divided by height in meters squared for children older than 2 years) obtained using medical records, staff measurements, caregiver reports, or remote study measures. The analysis was conducted using a multiphase latent growth mixture model. RESULTS/UNASSIGNED:This study included 9483 children (4925 boys [51.9%]). Two distinct 2-phase BMI patterns were identified: typical and atypical. The typical group (n = 8477 [89.4%]) showed linear decreases in BMI (b2, -0.23 [95% CI, -0.24 to -0.22]), with the lowest BMI at age 6 years (95% CI, 5.94-6.11), followed by linear increases from 6 to 9 years (slope difference [b4 - b2], 0.81 [95% CI, 0.76-0.86]; mean BMI at 9 years: 17.33). The atypical group (n = 1006 [10.6%]) showed a stable BMI from ages 1 to 3.5 years (b6, 0.06 [95% CI, -0.04 to 0.15]), followed by rapid linear increases from ages 3.5 to 9 years (slope difference [b8 - b6], 1.44 [95% CI, 1.34-1.55]). At age 9 years, this group reached a mean BMI (26.2) that exceeded the 99th percentile. Prenatal smoking, high prepregnancy BMI, high gestational weight gain, and high birth weight were key risk factors for the atypical trajectory. CONCLUSIONS AND RELEVANCE/UNASSIGNED:In this cohort study of children in the ECHO cohort, analyses identified children on the path to obesity as early as age 3.5 years. Modifiable factors could be targeted for early prevention and intervention programs aimed at reducing childhood obesity.

Environmental exposures often exhibit temporal variability, prompting extensive research to understand their dynamic impacts on human health. There has been a growing interest in studying time-dependent exposure mixtures beyond a single exposure. However, current analytic methods typically assess each exposure individually or assume an additive relationship. This paper aims to fill the gap in method development for evaluating the joint effects of multiple time-dependent exposures on a scalar outcome. We introduce a dynamic single-index scalar-on-function model to characterize the exposure mixture's time-varying effect through a non-parametric bivariate exposure-time-outcome surface function. Utilizing B-spline tensor product bases to approximate the surface function, we propose a profiling algorithm for model estimation and establish large-sample properties for the resulting single-index estimators. In addition, we introduce a non-parametric hypothesis testing procedure to determine whether the surface function varies over time at each fixed mixture level and a model averaging solution to circumvent the issue of knot selection for spline approximations. The performance of our proposed methods is examined through extensive simulations and further illustrated using real-world applications.

Humans are widely exposed to synthetic chemicals, especially via food. The types of chemical contaminants in food (including food contact chemicals) are diverse, and many of these are known to be hazardous, with mounting evidence that some contribute to noncommunicable diseases. The increasing consumption of ultra-processed foods, which contain synthetic chemicals, also contributes to adverse health. If the chemical contamination of foods were better characterized, then this issue would likely receive more attention as an important opportunity for disease prevention. In this Review, we discuss types and sources of synthetic food contaminants, focusing on food contact chemicals and their presence in ultra-processed foods. We outline future research needs and highlight possible responses at different food system levels. A sustainable transition of the food system must address the health impacts of synthetic chemicals in food; we discuss existing solutions that do justice to the complexity of the issue while avoiding regrettable substitutions and rebound effects.

BACKGROUND:Exposure to endocrine-disrupting chemicals such as bisphenols and phthalates might lead to adverse fertility and early pregnancy outcomes. METHODS:This study was embedded in the Generation R Next Study, a population-based cohort study from preconception onwards. Urinary phthalate and bisphenol concentrations were assessed in the preconception period (938 women), defined as the period in which couples were actively trying to conceive, and early pregnancy (1,366 women and 1,202 men, mean gestational age at sampling 8·6 weeks). Time to pregnancy and miscarriage were assessed using questionnaires and ultrasounds. Subfertility was defined as the inability to conceive within 12 months or need for assisted reproductive technologies. FINDINGS/RESULTS:Higher preconception urinary bisphenol S (BPS) and cyclohexane-1,2-dicarboxylic acid-monocarboxy isooctyl ester (mCOCH) concentrations in women were associated with longer time to pregnancy. Higher preconception mono-[(2-carboxymethyl)hexyl] phthalate, mono-2-ethyl-5-oxohexyl phthalate (mEOHP), mono-(7-carboxy-n-heptyl)phthalate (mCHpP), and mono benzyl phthalate (mBzBP) were associated with shorter time to pregnancy, and higher mono-2-ethyl-5-hydroxyhexyl phthalate (mEHHP), mEOHP, and mBzBP with lower odds of subfertility. In men, higher early pregnancy BPS, mCHpP, mono-4-methyl-7-hydroxyoctyl phthalate, mono-4-methyl-7-oxooctyl phthalate, and mono-ethyl phthalate were associated with shorter time to pregnancy or lower odds of subfertility. Higher preconception or early pregnancy BPS, phthalic acid, and mCHpP in women were associated with lower odds of miscarriage, whereas higher mono-carboxy-isoctyl phthalate, mCOCH, and mono-2-(propyl-6-carboxy-hexyl)-phthalate (cxmPHxP) with higher odds of miscarriage (all p-values <0·05). INTERPRETATION/CONCLUSIONS:Preconception and early pregnancy exposure to bisphenols and phthalates may affect couple fertility. Our results should be considered as hypothesis generating and replicated in future studies, possibly including repeated chemical measurements and mixture analysis.

BACKGROUND:New evidence has emerged that plastic polymers and their chemical additives, particularly di-2-ethylhexylphthalate (DEHP), contribute to cardiovascular disease (CVD). Phthalates are commonly used in the production of plastic materials and have been linked to increased oxidative stress, metabolic dysfunction, and cardiovascular disease. Estimates of phthalate-attributable cardiovascular mortality have been made for the US, but global estimates are needed to inform ongoing negotiations of a Global Plastics Treaty. METHODS:Cardiovascular mortality data from the Institute for Health Metrics and Evaluation (IHME) and regional DEHP exposure estimates from several sources were used to estimate burden. Hazard ratios of CV mortality were calculated using published exposure estimates, and country-level cardiovascular mortality rates were used to calculate excess deaths and years of life lost (YLL) due to DEHP exposure. FINDINGS/RESULTS:In 2018, an estimated 356,238 deaths globally were attributed to DEHP exposure, representing 13.497% of all cardiovascular deaths among individuals aged 55-64. Of these, 349,113 were attributed to the use of plastics. Geographic disparities were evident, with South Asia and the Middle East suffering the greatest percentage of cardiovascular deaths attributable to DEHP exposure (16.807%). The Middle East, South Asia, East Asia, and the Pacific accounted for the largest shares of DEHP-attributable CVD deaths (73.163%). Globally, DEHP resulted in 10.473 million YLL. INTERPRETATION/CONCLUSIONS:Plastics pose a significant risk to increased cardiovascular mortality, disproportionately impacting regions which have developing plastic production sectors. The findings underscore the need for urgent global and local regulatory interventions to kerb mortality from DEHP exposure. FUNDING/BACKGROUND:Bloomberg Philanthropies and the National Institutes of Health.

OBJECTIVE:Maternal vitamin D level is an important determinant of pregnancy and child health outcomes. Exposure to air pollution is suspected to increase the risk of vitamin D deficiency, but the evidence is scarce. We investigated the association between air pollution during pregnancy and maternal vitamin D levels. METHODS:A total of 15,935 pregnant women from 5 birth cohorts in Europe and U.S were included. Averaged concentrations of nitrogen oxides, fine and coarse particles, and composition of fine particles from conception until vitamin D measurement were estimated at participants' residential addresses using land-use regression or other spatiotemporal models. Cohorts measured vitamin D as 25(OH)D or 25(OH)D3 levels in serum or plasma at early or mid-pregnancy. We defined suboptimal vitamin D levels as levels below 20 ng/mL. We performed logistic regression models for each cohort to estimate the association between air pollution exposure and suboptimal vitamin D levels and pooled cohort-specific estimates in a random-effect meta-analysis. Models were adjusted for sociodemographic and lifestyle characteristics and month of conception. RESULTS:We found an association between PM2.5 and higher odds of suboptimal vitamin D levels (i.e., below 20 ng/mL) (odds ratio per 5 μg/m3 increase in PM2.5, 1.43 95%CI: 1.02, 1.99). There was no association between other air pollutant exposure and vitamin D levels. CONCLUSIONS:PM2.5 exposure might contribute to suboptimal levels of vitamin D in pregnancy. Reducing air pollution exposure should be a priority because vitamin D deficiency may adversely influence offspring development.