Measurement of Non-Persistent Pesticides in Postpartum Meconium as a Biomarker of Prenatal Exposure: A Validation Study

EPA Grant Number: R828609
Title: Measurement of Non-Persistent Pesticides in Postpartum Meconium as a Biomarker of Prenatal Exposure: A Validation Study
Investigators: Whyatt, Robin M. , Barr, Dana Boyd , Camann, David , Kinney, Patrick L. , Matseoane, Stephen , Perera, Frederica P. , Tsai, Wei-Yann
Institution: Columbia University in the City of New York , Centers for Disease Control and Prevention , Southwest Research Institute
EPA Project Officer: Laessig, Susan A.
Project Period: September 28, 2000 through March 28, 2005 (Extended to June 28, 2005)
Project Amount: $744,866
RFA: Biomarkers for the Assessment of Exposure and Toxicity in Children (2000) RFA Text |  Recipients Lists
Research Category: Children's Health , Health Effects , Human Health , Health

Description:

The goal is to validate a new biomarker of cumulative prenatal exposure to organophosphates and other non-persistent pesticides. Specifically, the study seeks to determine if levels of the pesticides in postpartum meconium reflect exposures during the last two months of pregnancy. A cumulative biomarker is needed to facilitate evaluation of health impacts associated with exposures during pregnancy, given the widespread residential use of these pesticides. Experimental data have linked prenatal organophosphate exposure to adverse neurocognitive development. Exposures during the spurt in brain growth (beginning in humans during the 3rd trimester) appear particularly deleterious. However, epidemiologic research on this relationship has been hampered by the lack of reliable dosimeters. Existing biomarkers (including urine and blood levels) reflect short-term exposure only. Our prior research has shown that the pesticides can be quantified in meconium. Meconium begins to form during the 2nd trimester but is not generally excreted until after delivery. Xenobiotics enter meconium through bile secretion and/or swallowing by the fetus of amniotic fluid. Evidence suggests significant trapping of xenobiotics in meconium, with measured levels reflecting months of exposure. Hypotheses are: 1) levels of organophosphates and other non-persistent pesticides measured in postpartum meconium reflect cumulative exposures during the 8th and 9th months of pregnancy; 2) levels of the pesticides in postpartum meconium provide a more reliable dosimeter of cumulative exposure than levels of the pesticides in maternal or newborn postpartum urine samples.

Approach:

The cohort will consist of 100 pregnant African American and Dominican women from Northern Manhattan or the South Bronx. Our research has shown widespread pesticide exposure during pregnancy among this minority population. Levels of the organophosphate and other non-persistent pesticides will be measured in indoor air monitored continuously (with pumps timed to sample for 10 minutes/hour) at the woman's residence during each of the 8th and 9th months of pregnancy. Questionnaire data will include the amount of time the woman has spent in the home during the monitoring. Pesticides or their metabolites will be measured in paired meconium and urine (maternal & newborn) samples collected at delivery by the Centers for Disease Control (CDC).

Expected Results:

We anticipate the study to validate a biomarker of cumulative prenatal exposure to organophosphates and other non-persistent pesticide. Specifically, we expect results to show that levels of the non-persistent pesticides in postpartum meconium reflect cumulative exposures during the 8th and 9th months of pregnancy. In the human fetus, this period in gestation coincides with the spurt in brain growth. Our hypothesis is based on a number of lines of evidence indicating that the meconium can serve as a reservoir for xenobiotics and provide information about exposures over the latter part of pregnancy.

A biomarker of cumulative exposure would help improve Risk Assessments. Experimental studies have linked prenatal organophosphate exposure to adverse neurocognitive sequelae. Recent evidence suggests that exposures may be more dangerous than previously thought. Acetylcholinesterase, and the related enzyme, butyrylcholinesterase (also a target of organophosphates) appear to play an important role in neurologic development. Prenatal exposures to organophosphates may disrupt this function. Exposures during the spurt in brain growth may be particularly deleterious. Residential pesticide use is widespread in the U.S. and resultant exposures can be high relative and have been shown in some cases to approach, or even exceed, health-based standards. What is not know is whether the levels of pesticide exposures from residential use typically encountered during pregnancy are associated with any adverse neurocognitive sequelae in the human newborn. Epidemiologic research on this relationship has been hampered by uncertainties in exposure estimates and by the lack of biomarkers reflecting cumulative prenatal exposure. We anticipate that this research will fill an important gap by validating such a biomarker.

Publications and Presentations:

Publications have been submitted on this project: View all 17 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 5 journal articles for this project

Supplemental Keywords:

ambient air, newborn, developmental, insecticides, epidemiology., RFA, Health, Scientific Discipline, Toxics, Geographic Area, Toxicology, Environmental Chemistry, Health Risk Assessment, pesticides, State, Susceptibility/Sensitive Population/Genetic Susceptibility, Children's Health, genetic susceptability, Biology, health effects, pesticide exposure, risk assessment, minority population, sensitive populations, validation study, xenobiotics, postpartum meconium, prenatal exposure, biomarkers, exposure, neurodevelopmental, neurotoxicity, children, insecticides, growth and development, pesticide residues, environmental toxicant, neurobehavioral effects, biological markers, growth & development, developmental disorders, exposure assessment, organophosphate pesticides, New York (NY), environmental hazard exposures

Relevant Websites:

Synthesis Report of Research from EPA’s Science to Achieve Results (STAR) Grant Program: Feasibility of Estimating Pesticide Exposure and Dose in Children Using Biological Measurements (PDF) (42 pp, 3.87 MB)

Progress and Final Reports:

2000 Progress Report
2002 Progress Report
2004 Progress Report
Final Report