Grantee Research Project Results
2000 Progress Report: Measurement of Non-Persistent Pesticides in Postpartum Meconium as a Biomarker of Prenatal Exposure: A Validation Study
EPA Grant Number: R828609Title: Measurement of Non-Persistent Pesticides in Postpartum Meconium as a Biomarker of Prenatal Exposure: A Validation Study
Investigators: Whyatt, Robin M. , Barr, Dana Boyd , Kinney, Patrick L. , Perera, Frederica P. , Camann, David , Matseoane, Stephen , Tsai, Wei-Yann
Institution: Southwest Research Institute
Current Institution: Columbus State University , Centers for Disease Control and Prevention , Southwest Research Institute
EPA Project Officer: Hahn, Intaek
Project Period: September 28, 2000 through March 28, 2005 (Extended to June 28, 2005)
Project Period Covered by this Report: September 28, 2000 through March 28, 2001
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 , Human Health
Objective:
The goal of this research project is to validate a new biomarker of cumulative prenatal exposure to organophosphates and other nonpersistent pesticides. Specifically, the study seeks to determine if levels of the pesticides in postpartum meconium reflect exposures during the last 2 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 third 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 second 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.Progress Summary:
The study began with a 3-month startup to hire and train personnel, develop questionnaires, pilot monitoring strategies, and conduct quality assurance assessments (see below). The indoor air monitoring protocols were revised to operate pumps continuously throughout the eighth and ninth months of pregnancy, which should ensure that peak exposures are not missed.Enrollment and Indoor Air Monitoring
Enrollment into the study began in February 2001. As of December 1, a total of 56 women had been enrolled into the study at an average rate of 5.6 women/month. Indoor air monitoring over the eighth and ninth months of pregnancy has been completed for 29 women and is currently ongoing for an additional 6 women. Of the remaining 20 women, the monitoring is scheduled but has not yet begun for 8 women, and 13 have been lost to followup. The rate of loss-to-followup (23 percent) is somewhat less than the rate projected when we proposed the grant (30 percent). Laboratory analysis of the 10 target pesticides has been completed for 42 indoor air monitoring filters collected from 10 women and is currently ongoing for 69 air monitoring filters collected from an additional 16 women. The filters from the remaining three women are currently stored at Columbia and will be shipped to the Southwest Research Institute for laboratory analysis in January. Data analysis on completed air monitoring results is ongoing.
Questionnaires and Data Inputting
Questionnaires are being administered to all study women every 2 weeks during the eighth and ninth months of pregnancy. Questions on pesticide use include whether pests were seen in the home during the 2-week period, whether pest control measures were used and, if so, which methods were used and how frequently. The database for the questionnaires, air monitoring results, and results of the biologic samples has been constructed, and data input is ongoing.
Biologic Samples Collection
A maternal urine sample is being collected biweekly from all women during the indoor air monitoring. Twenty-nine women in the cohort have delivered to date, and the following biologic samples were collected at delivery: a postpartum meconium sample from 25 (86 percent) newborns; a postpartum urine sample from 24 (83 percent) newborns and 25 (86 percent) mothers; and a blood sample (maternal and/or umbilical cord) from 29 (100 percent) of the mother/newborn pairs. These rates of sample collection are consistent with the targets originally outlined in the grant. Samples are being shipped to the Centers for Disease Control and Prevention on dry ice and laboratory analyses currently are ongoing.
Results of Pilot Studies on Pesticide Levels in Biologic Samples
To finalize selection of the pesticides that will be measured in meconium samples collected from newborns in the current study, meconium samples from newborns in the Columbia Center for Children's Environmental Health (the Center) study have been analyzed for levels of 6 common organophosphate metabolites and 43 pesticides or their chemical-specific metabolites. These pilot studies were undertaken to investigate the full range of pesticides that are found in postpartum meconium, as few prior data on pesticide levels in meconium are available. Newborns from the Center cohort were selected for the pilot study because enrollment criteria into the Center study are essentially the same as enrollment criteria in the current study. Specifically, the studies are restricted to African American and Dominican mothers and newborns residing in Washington, Harlem, or the South Bronx regions of New York City. Further, our prior research has shown widespread pesticide use and exposure during pregnancy among women in the Center cohort (Whyatt, et al., Environmental Health Perspectives, in press): 85 percent of the women reported using pest control measures during pregnancy, and all of the women who completed the 48-hour ambient air monitoring during pregnancy (n=166) were exposed to the organophosphates chlorpyrifos and diazinon in their personal air. The 6 common organophosphate metabolites were measured in 12 meconium samples collected from Center newborns. Diethylphosphate (DEP) and diethydithiophosphate (DETP), which are common metabolites of both diazinon and chlorpyrifos, were detected in 100 percent of the samples (range 1.2 to 10 and 3 to 30 [g/g, respectively]). Diethyldithiophosphate (DEDTP) was detected in 92 percent of samples (range ND-16.5); dimethylphosphate (DMP) in 33 percent (ND-21 [g/g]); dimethylthiophosphate (DMTP) in 75 percent (ND-62 [g/g]); and dimethyldithiophosphate (DMDPT) in 67 percent (range ND-65 [g/g]). These rates of detection and metabolite concentration levels are considerably higher than seen previously in our study of meconium collected anonymously (without knowledge of prenatal pesticide use) from newborns who delivered at New York Presbyterian Hospital (see Whyatt and Barr, 2001;109:414-420). Of the 43 pesticides that were analyzed, 13 were detected in more than 25 percent of samples. These included the following insecticides (or their chemical-specific metabolites): diazinon, parathion/methyl parathion, dichlorvos, malation, bendiocarb, carbaryl, cis- and trans-permethrin, and cyfluthrin. Also detected was one herbicide (alachlor) and two fungicides, or their chemical-specific metabolite (dichloran and folpet).
Future Activities:
We will continue to enroll and monitor women during pregnancy, to collect questionnaire data and biologic samples, and to analyze pesticide levels in the meconium and other biologic samples.Journal Articles:
No journal articles submitted with this report: View all 15 publications for this projectSupplemental Keywords:
ambient air, newborn, developmental, insecticides, epidemiology., RFA, Scientific Discipline, Health, Toxics, Geographic Area, Toxicology, Environmental Chemistry, Health Risk Assessment, State, pesticides, 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 exposuresRelevant Websites:
http://cpmcnet.columbia.edu/dept/sph/ccceh/index.html Exit 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:
Original AbstractThe 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.