Pilot Projects

Title: Pesticides in postpartum meconium as a biomarker of fetal exposure among African American and Dominican newborns residing in Northern Manhattan and the South Bronx

Investigator: Robin Whyatt, DrPH  

Description: A pilot study was funded to evaluate whether measurements of organophosphates (OP) and other non-persistent pesticides in postpartum meconium provides a  dosimeter of prenatal exposures over the latter part of pregnancy. In the initial step of biomarker validation, OP metabolites were measured in meconium samples collected anonymously from 20 newborns. The purpose of this initial step was to determined background levels, detection limits and stabilities of OP metabolites in meconium. Six metabolites were analyzed. Diethylphosphate (DEP) and diethylthiophosphate (DETP) both metabolites of the pesticides diazinon and chlorpyrifos, which are widely used for residential pest control and dimethylphosphate (DMP) and diethyldithiophosphate (DEDTP) were each detected.  Dimethylthiophosphate (DMTP) and dimethyldithiophosphate (DMDTP) were not detected.  Detection limits were comparable to or lower than detection levels in urine; levels were similar to those seen in adult urine in population-based research. In addition, pesticide levels are being measured in postpartum meconium that is being collected on newborns enrolled into the prospective cohort conducted by the Columbia Center for Children’s Environmental Health. Pesticide levels are also being measured in: 1) air monitoring filters collected over 48-hours of personal ambient air monitoring of cohort women during pregnancy; 2) maternal urine samples collected during pregnancy; and 3) maternal and umbilical cord blood samples collected at delivery. Analyses of the pesticides in the biologic samples are being conducted by Dr. Dana Barr, Chief, Non-persistent Pesticide Laboratory, CDC. Analysis of pesticide levels in the air monitoring filters is being conducted by David Camann at Southwest Research Institute.

To date, meconium has been collected at birth on 58 newborns in the Center cohort; 31 of these samples have been shipped to the CDC for pesticide analyses. CDC has completed analysis of pesticide levels in the first 12 meconium samples. OP metabolites were detected more frequently and at higher concentration in the meconium samples from the newborns in the Center cohort than in the meconium samples that were collected anonymously. These results indicate that measurements of OP metabolites in meconium have promise as biomarkers of prenatal exposure.

Grant: A three-year STAR grant from the U.S. Environmental Protection Agency (EPA R82860901) has been obtained based on results of these preliminary studies to provide more in-depth validation of non-persistent pesticides in postpartum meconium as a biomarker of prenatal exposure. NIEHS RO1 is: Validation of biomarkers of prenatal pesticide exposure(#RO1 ES115801)

Publication: Whyatt,R.M. Barr,D.B.Measurement of orgaonphosphate metabolites in postpartum meconium as a potential biomarker of prenatal exposure: a validation study Environ Health Perspect 109: 417-420, 2001