Research
Dr. Meeker and his research group have been involved in projects that span a range of topics in environmental and occupational health. Recent interests include exposure assessment and epidemiology studies investigating health impacts associated with exposure to pesticides, phthalates, phenols, flame retardants, and other agents, as well as approaches to evaluate, minimize, and account for exposure measurement error in epidemiology studies. Within this area of study much of the research the team conducts has a particular focus on the study of exposure biomarkers and environmental factors associated with reproductive health and child development. These research topics and projects range over several life stages, and windows of vulnerability.
Current Projects Include:
PROJECT 1 Puerto Rico Testsite for Exploring contamination Threats (PROTECT), R01 NIEHS
PROTECT is a multi-project, multi-institution collaboration that involves five primary institutions: Northeastern University, University of Puerto Rico, Medical Sciences Campus, University of Puerto Rico, Mayaguez, University of Georgia, and University of Michigan. PROTECT studies exposure to environmental contamination in Puerto Rico and its contribution to adverse pregnancy outcomes, including preterm birth (less than 37 completed weeks of gestation). Rates of preterm birth and infant mortality in Puerto Rico are among the highest of all US states and territories.
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Environmental Influences on Child Health Outcomes in Puerto Rico (ECHO-PRO), UG3 NIEHS
The goal of the Environmental influences on Child Health outcomes (ECHO) Program is to understand the effects of a broad range of early environmental influences on child health and development. ECHO is dedicated to both learning what factors affect child health and to finding ways to enhance it.
The ECHO Program studies five areas of health. These include pre-, peri-, and postnatal (pregnancy and birth), upper and lower airway (breathing), obesity (body weight), neurodevelopment (brain development) and positive health (well-being).
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Pregnancy Exposures to Chemical Mixtures and Later Metabolic Health and Endocrine Function Among Women in the Puerto Rico PROTECT Cohort (PROTECT MOMS), R01 NIEHS
A rapidly growing body of research shows that exposure to common environmental chemicals can disrupt endocrine and metabolic function, and negatively impact pregnancy outcomes and child development. Studies also demonstrate that certain pregnancy conditions (e.g., preeclampsia) and outcomes (e.g., preterm birth) are associated with adverse health later in the life of the mother. However, research is lacking on the relationships between exposures in pregnancy and later health of the mother, and how pregnancy outcomes impact those associations. Puerto Rico suffers from elevated rates of numerous morbidities compared to the mainland U.S., including preterm birth and Type II diabetes. Puerto Rico also has a history of extensive contamination with increased human exposure to a range of pollutants. We established the PROTECT cohort in the northern coast of Puerto Rico to study the impacts of exposure to an array of environmental chemicals during gestation and adverse pregnancy outcomes. We have developed an incredibly rich dataset on exposures, biomarkers of intermediate effects, questionnaires, and health record information. PROTECT is also a participating cohort within the newly established US-wide ECHO study, following the development of children born into PROTECT. We propose building upon this vast dataset and continued recruitment in PROTECT, along with the repeated participant contact during the ECHO follow-up visits, to investigate status and longitudinal trajectories of maternal metabolic health and endocrine function for up to five years following pregnancy among 1000 women in Puerto Rico. We have exposure biomarker data from repeated samples collected in pregnancy on urinary phthalate metabolites, phenols/parabens, and PAH metabolites, as well as 17 metals measured in both urine and blood. In this study, with new data and sample collection on PROTECT mothers at 6 months, 1 year, 2 years, and 5 years following delivery, we aim to: 1) Determine whether maternal exposures during pregnancy are associated with measures and trajectories of metabolic health (i.e., body size, body composition, physical strength, clinical diagnoses, blood pressure, and blood glucose, insulin, lipids, HbA1c) in short- and long-term follow-up assessments after delivery; 2) Investigate the relationships between maternal exposures during pregnancy and longitudinal measures of endocrine function (e.g., estradiol, testosterone, SHBG, FSH and AMH) in the follow-up assessments after delivery; and 3) Explore effect modification of the associations between pregnancy exposures and later women’s health from the first two aims by pregnancy complications (gestational diabetes, preeclampsia, preterm birth), and/or by social determinants (socioeconomic status, social support, depression, stress, life experiences, and others) and other physical determinants of health (body size, physical activity, breast feeding, polycystic ovarian syndrome, menstrual patterns, and others). The expected outcomes of this study are to provide new and much needed information on the impacts of pregnancy exposures, pregnancy outcomes, and social factors on women’s health.
Applying and advancing modern approaches for studying the joint impacts of environmental chemicals on pregnancy outcomes (LIFECODES), R01 NIEHS
Preterm birth is a significant public health challenge due to increasing rates over time, as well as serious consequences for infant mortality, childhood morbidity, and economic costs to society. Conditions that contribute to preterm birth remain unclear, though an influence by environmental chemical exposures is suspected but poorly understood. Establishing links with common environmental chemicals could have huge public health impact since many exposures could be modifiable through remediation, policies or other interventions. Low birth weight and fetal growth restriction also represent a great public health challenge, as they too have increased in recent decades and may be influenced by modifiable exposures to environmental chemicals. This project proposes to leverage the established Boston Lifecodes cohort study (N~4,000) of risk factors for preterm birth and other adverse pregnancy outcomes, with a focus on exposure to mixtures of commonly-encountered chemicals. We propose to select 1,000 singleton births from Lifecodes with detailed information and samples collected at multiple times during pregnancy. We will then utilize state-of-the-art methods to estimate biomarkers of exposure to chemical mixtures (per- and polyfluorinated substances [PFAS], phthalates and phthalate replacement chemicals, polycyclic aromatic hydrocarbons [PAH], and metals/metalloids), in addition to intermediate biomarkers of effect and repeated ultrasound measures of fetal growth, in order to provide much needed human data on environmental and other predictors of pregnancy outcomes and insights on the biological pathways involved. Results from our preliminary work show that oxidative stress may be an important link between exposure and outcome that needs to be explored in more depth using the proposed pathway-specific biomarkers. To accomplish our aims we will develop innovative statistical and machine learning approaches for analyzing mixtures and mediation with high-dimensional mediator sets, with the goal of improving our ability to discover and define these relationships. Finally, a study sub-aim is to identify conditions/activities contributing to high exposures that can inform exposure reduction strategies. The expected outcomes of this study are new and much needed information on the magnitude, sources, and impacts of exposure to commonly encountered chemicals, both individually and in combination, among pregnant women, and innovative methods for identifying relevant biological pathways and assessing health impacts from exposure to mixtures. Our findings will have a significant impact on public health given widespread exposure to the target chemicals, the growing need to identify environmental agents that adversely impact pregnancy, and the need to discover contributors to the high rates of preterm birth in the U.S. and beyond that could be prevented. Our study will also provide new information on the role of oxidative stress in adverse pregnancy outcomes which may inform future therapeutic or preventative interventions, and contribute new statistical and machine learning methods for investigating mixtures, mediation, and birth outcomes.