Mediation with External Summary Statistic Information.

Environmental health studies are increasingly measuring endogenous omics data ($ \boldsymbol{M} $) to study intermediary biological pathways by which an exogenous exposure ($ \boldsymbol{A} $) affects a health outcome ($ \boldsymbol{Y} $), given confounders ($ \boldsymbol{C} $). Mediation analysis is frequently performed to understand such mechanisms. If intermediary pathways are of interest, then there is likely literature establishing statistical and biological significance of the total effect, defined as the effect of $ \boldsymbol{A} $ on $ \boldsymbol{Y} $ given $ \boldsymbol{C} $.

Prenatal exposure to phthalates and alternative plasticizers and emotional and behavioral outcomes in early childhood in the Environmental influences on Child Health outcomes (ECHO) cohort.

Background: Evidence suggests prenatal phthalate exposure adversely affects children's behavior. However, epidemiological studies on alternative plasticizers remain scarce. This study investigated associations of gestational exposure to phthalates and alternative plasticizers with internalizing and externalizing behaviors in children aged 1.

Examining the association between gestational phenol exposure and infant non-nutritive suck in two Environmental influences on Child Health Outcomes cohorts.

Background: Non-nutritive suck (NNS) is a measure of neurofunction sensitive to environmental exposures in utero. This study aimed to evaluate the relationship between gestational phenol exposure and NNS patterning.

Methods: Mother-infant pairs from two diverse prospective cohorts were enrolled in the Environmental influences on Child Health Outcomes Program.

Dietary Intake Is Associated with Biomarkers of Lead, Arsenic, and Cadmium in a Cohort of Mexican Adolescents.

Background: Lifestyle changes during adolescence can impact dietary habits and, subsequently, exposure to heavy metals.

Objectives: We aimed to evaluate the associations between food group intakes and metal exposures in a cohort of adolescents.

Methods: This study included 416 adolescents from Mexico City aged 10-18.

Prenatal exposure to phthalate mixtures and child neurodevelopment in toddlers aged 1-3 years from the PROTECT birth cohort.

Phthalates are widely used plasticizers and solvents in a variety of consumer and personal care products, resulting in ubiquitous exposure across the general population. Pregnancy represents a particularly critical window of vulnerability, as prenatal phthalate exposures have been linked to adverse health outcomes, including preterm birth and child developmental problems. While growing evidence highlights potential neurotoxic effects in children, few studies have examined the combined impact of multiple phthalates and newly introduced replacement chemicals.

Statistical Methods for Chemical Mixtures: A Roadmap for Practitioners Using Simulation Studies and a Sample Data Analysis in the PROTECT Cohort.

Background: Quantitative characterization of the health impacts associated with exposure to chemical mixtures has received considerable attention in current environmental and epidemiological studies. With many existing statistical methods and emerging approaches, it is important for practitioners to understand which method is best suited for their inferential goals.

Objective: The goal of this paper is to provide empirical simulation-based evidence regarding performance of mixture methods to help guide researchers on selecting the best available methods to address three scientific questions in mixtures analysis: identifying important components of a mixture, identifying interactions among mixture components, and creating a summary score for risk stratification and prediction.

Associations between urinary polycyclic aromatic hydrocarbon biomarker concentrations and birth outcomes in the LIFECODES cohort.

Environmental exposure to polycyclic aromatic hydrocarbons (PAH) is ubiquitous and may impact fetal development leading to adverse birth outcomes. PAHs result from incomplete combustion and exposure sources include inhalation of cigarette smoke and car exhaust, ingestion of charred meat, and many others. The purpose of this study was to determine associations between prenatal PAH biomarker concentrations and birth outcomes.

Maternal thyroid dysfunction and depressive symptoms during pregnancy and child behavioral and emotional problems - an ECHO multi-cohort investigation.

Background: Maternal thyroid dysfunction and maternal depression during pregnancy may increase the risk of child behavioral and emotional problems. We sought to investigate the independent and interactive associations of these two risk factors with child behavior problems.

Methods: We combined data from four cohorts in the Environmental influences on Child Health Outcomes (ECHO) program (N = 949).

Associations among PM, corticotropin releasing hormone, estriol, and progesterone in pregnant persons in Puerto Rico.

Exposure to PM is associated with adverse birth outcomes and early development. Pregnancy is typically characterized by the production of several important hormones that impact aspects of maternal and fetal physiology, including progesterone, estriol, and corticotropin releasing hormone (CRH). No previous studies have examined PM associations in pregnant persons for CRH and estriol.

Association between organic micropollutants in tap water and human exposure and birth outcomes: Implications for environmental health in northern Puerto Rico.

The presence of micropollutants in Puerto Rico's tap water, potentially linked to nearby Superfund sites, was hypothesized to contribute to the region's higher preterm birth rate than the US mainland. This study analyzed the presence of 175 micropollutants in tap water samples collected from participant households and evaluated their association with human exposure using 14 oxidative stress and inflammation biomarkers in urine samples collected from pregnant participants, and further with the subsequent birth outcome information. Notably, three out of four oxidative stress biomarkers consistently showed negative correlations with five micropollutant categories, highlighting the oxidative stress induced by these contaminants.

Periods of susceptibility for associations between phthalate exposure and preterm birth: Results from a pooled analysis of 16 US cohorts.

Background: Phthalate exposure during pregnancy has been associated with preterm birth, but mechanisms of action may depend on the timing of exposure.

Objective: Investigate critical periods of susceptibility during pregnancy for associations between urinary phthalate metabolite concentrations and preterm birth.

Methods: Individual-level data were pooled from 16 US cohorts (N = 6045, n = 539 preterm births).

Assessment of per- and polyfluoroalkyl substances (PFAS) exposure and associations with oxidative stress biomarkers among pregnant women from the PROTECT cohort.

Introduction: Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals linked with adverse pregnancy outcomes, yet they remain understudied in Puerto Rico. Moreover, underlying biological mechanisms of PFAS are not fully understood, although oxidative stress and inflammation are suspected pathways.

Objectives: We aimed to characterize PFAS exposure among pregnant women in Puerto Rico and examine associations between early to mid-pregnancy PFAS concentrations and repeated measures of oxidative stress biomarkers.

Neurobehavioral effects of gestational exposure to mixtures of non-persistent endocrine disruptors in preschool-aged children: The environmental influences on child health outcomes (ECHO) program.

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.

Consumer Product Chemical Mixtures and Oxylipin-Mediated Inflammation and Oxidative Stress during Early Pregnancy: Findings from a Large US Pregnancy Cohort.

Consumer product chemicals pose an environmental risk to public health. Exposure during pregnancy to consumer product chemicals, particularly phthalates and phenols, may increase the susceptibility to pregnancy disorders by dysregulating inflammation and oxidative stress. However, existing studies rely on downstream and nonmodifiable markers of these processes.

Associations Between Ambient PM and Thyroid Hormones in Pregnant Persons in Puerto Rico.

Introduction: This study investigates associations between fine particulate air pollution (PM) exposure and thyroid hormone levels during pregnancy in Puerto Rican individuals, a vulnerable population facing socioeconomic and environmental disparities.

Methods: This research draws on data from the PROTECT cohort study and involves 1040 participants to measure the effect of PM on developmentally important thyroid hormones (TSH, T3, T4, and FT4). Pollution concentrations were linked to participant locations using EPA air quality data and analyzed across two visits during gestational weeks 16-20 and 24-28.

Associations of prenatal urinary melamine, melamine analogues, and aromatic amines with gestational duration and fetal growth in the ECHO Cohort.

Melamine, its analogues, and aromatic amines (AAs) were commonly detected in a previous study of pregnant women in the Environmental influences on Child Health Outcomes (ECHO) Cohort. While these chemicals have identified toxicities, little is known about their influences on fetal development. We measured these chemicals in gestational urine samples in 3 ECHO cohort sites to assess associations with birth outcomes (n = 1,231).

Prenatal exposure to environmental bisphenols over time and their association with childhood asthma, allergic rhinitis and atopic dermatitis in the ECHO consortium.

Concerns persist about the potential impact of prenatal exposure to bisphenols (BP) and their replacement analogues on childhood asthma and allergies. Previous studies on single and small cohorts had limited statistical power, few investigated analogues BPF and BPS, and even fewer examined atopic outcomes. Our objective was to assess whether prenatal exposures to individual environmental bisphenols (BPA, BPF, BPS) influence risk of childhood asthma, allergic rhinitis, and atopic dermatitis.

Prenatal exposure to per- and polyfluoroalkyl substances (PFAS) and their influence on inflammatory biomarkers in pregnancy: Findings from the LIFECODES cohort.

Background: Per- and polyfluoroalkyl substances (PFAS) are fluorinated chemicals linked to adverse pregnancy and birth outcomes. However, the underlying mechanisms, specifically their effects on maternal inflammatory processes, are not well characterized.

Objective: We examined associations between prenatal PFAS exposure and repeated measures of inflammatory biomarkers, including C-reactive protein (CRP) and four cytokines [Interleukin-10 (IL-10), IL-1β, IL-6, and tumor necrosis factor-α (TNF-α)].

Changes in exposure to environmental contaminants in the aftermath of Hurricane Maria among pregnant women in northern Puerto Rico.

Experiencing a hurricane during pregnancy is associated with increased risk of adverse birth outcomes and poor mental health. Pregnant people from marginalized communities are more susceptible to adverse effects, as they have fewer resources to overcome hardships at a time when shelter and nutrition are essential. When Hurricane Maria (HM) devastated Puerto Rico in September 2017, the archipelago was already burdened with high poverty, health disparities, environmental contamination, and fragile utility infrastructure.

Exposure to organophosphate ester flame retardants and plasticizers and associations with preeclampsia and blood pressure in pregnancy.

Background: Organophosphate esters (OPEs), flame retardants and plasticizers found widely in consumer products, may impact vascularization processes in pregnancy. Yet, the association between maternal exposure to OPEs and both preeclampsia and blood pressure during pregnancy remains understudied.

Methods: Within the LIFECODES Fetal Growth Study (N = 900), we quantified 8 OPE metabolites from maternal urine collected at up to 3 time points during pregnancy and created within-subject geometric means.

Association of Phenols, Parabens, and Their Mixture with Maternal Blood Pressure Measurements in the PROTECT Cohort.

Background: Phenols and parabens are two classes of high production volume chemicals that are used widely in consumer and personal care products and have been associated with reproductive harm and pregnancy complications, such as preeclampsia and gestational diabetes. However, studies examining their influence on maternal blood pressure and gestational hypertension are limited.

Objectives: We investigated associations between individual phenols, parabens, and their mixture on maternal blood pressure measurements, including systolic and diastolic blood pressure (SBP and DBP) and hypertension during pregnancy (defined as stage 1 or 2 hypertension), among Puerto Rico PROTECT study participants.