Grantee Research Project Results

A Novel Analytic Method for Evaluating Early Life Susceptibility to Chemical Stressors

EPA Grant Number: FP917790
Title: A Novel Analytic Method for Evaluating Early Life Susceptibility to Chemical Stressors
Investigators: Cowell, Whitney J
Institution: Columbia University in the City of New York
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2015 through August 31, 2018
Project Amount: $132,000
RFA: STAR Graduate Fellowships (2015) RFA Text | Recipients Lists
Research Category: Academic Fellowships

Objective:

Non-chemical stressors may modify individual susceptibility to environmental pollution, however, current techniques for measuring the cumulative physiological impact of social stressors on the body, known as allostatic load, are limited. The goal of this research is to develop and evaluate a novel analytic approach for assessing the effects of chemical stressors in the context of individual susceptibility. First, leukocyte telomere dynamics will be examined as a biomarker of allostatic load. Second, this biomarker will be evaluated as a tool for studying the joint effects of chemical and non-chemical stressors on human health.

Approach:

This research will leverage previously collected epidemiological data from a prospective birth cohort study of low-income, minority mothers and children. Relative telomere length will be measured using monochrome multiplex quantitative polymerase chain reaction in maternal leukocytes, umbilical cord leukocytes, and child leukocytes. Cord blood and peripheral blood PBDE concentrations for the same children have been previously measured by the Centers for Disease Control and Prevention and neurodevelopment has been assessed with a battery of validated instruments, including the Weschler Intelligence Scale for Children-IV and the Conners’ Continuous Performance Test-II. Regression models will be used to examine the association between social stressors and leukocyte telomere dynamics (length and rate of erosion). This will provide insight into which elements of social stress have the most significant impact on telomere length. A cumulative stress index will also be created by summing across measures. Longitudinal data analysis approaches, including latent class growth curve modeling, will be used to examine the trajectory of PBDE exposure and child neurodevelopment. The interaction between PBDEs, selected as a candidate environmental chemical of concern, and telomere dynamics (length and rate of erosion) will be statistically examined to evaluate effect modification by social stress.

Expected Results:

This research is expected to validate leukocyte telomeres as a biomarker of allostatic load. This will enable evaluation of more realistic exposure scenarios and potentially provide the capacity to identify subpopulations with the greatest susceptibility to environmental chemical exposures. The findings are expected to improve our understanding of why some children manifest more health problems, despite having comparable exposure to environmental chemicals. Specifically, this study is expected to improve our understanding of the joint impacts of chemical and non-chemical stressors on neurodevelopment.

Supplemental Keywords:

children's environmental health, risk assessment, susceptibility

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.