Project 3: Biomarker Epidemiology of In Utero Environmental Exposures and Child Development

Significance: There is much concern over recent increases in rates of preterm birth, birth anomalies of the male reproductive tract, precocious puberty in girls, childhood obesity, asthma/allergies, and certain neurodevelopmental disorders, such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). Such alarming trends signal an urgent need to identify contributing factors to these conditions to aid in effective prevention efforts. These developmental markers or disorders measured early in life can lead to long-term morbidity, and produce an enormous collective economic burden on communities like Puerto Rico, who show disproportionately high rates of these diagnoses. For example, in the past two decades, Puerto Rico has experienced a steep increase in preterm birth, and shown higher rates of childhood obesity, autism, and asthma than mainland U.S. In utero exposure to environmental chemicals, such as those classified as contaminants of emerging concern (CECs), may contribute to these adverse reproductive and developmental outcomes. Well-designed prospective human studies are needed to better establish and quantify risks of exposure to environmental chemicals on child health.

The primary goal of Project 3 is to assess the relationship between phenol and paraben exposure with fetal and child development. Project 3 researchers also use molecular epidemiology to explore underlying biological mechanisms based on compelling evidence that chemicals in these classes are associated with significant alterations in biomarkers of endocrine function, oxidative stress, and/or inflammation. Project 3 additionally explores whether conditions that are common among underserved populations, such as maternal stress, modify the effects of exposure to environmental chemicals to magnify detrimental outcomes in fetal and child development. Finally, individual chemicals or their metabolites within these classes of known or suspected reproductive and developmental toxicants can have multiple, diverse, and perhaps overlapping modes of action potentially in the causal pathway to adverse pregnancy and child development outcomes. To address this, Project 3 studies exposure to multiple chemicals, both individually and as mixtures to identify additive, synergistic, and/or antagonistic effects on human health endpoints.

Our findings are likely to have a significant impact on public health given widespread contaminant exposure, the growing concern for identifying environmental agents that adversely impact fetal and child development, and the need to discover contributors to recent trends in developmental disorders, particularly among those most affected in contaminated areas like Puerto Rico.

John Meeker, Project Leader

Bhramar Mukherjee, Co-Investigator

Deborah Jean Watkins, Postdoctoral Associate