You are here:
DETERMINANTS OF CHILDREN'S PESTICIDE EXPOSURE IN YUMA COUNTY, ARIZONA
Citation:
CHAPA, G., G. L. ROBERTSON, M. K. O'ROURKE, R. HART-MCELROY, R. SABOGAL, D. B. BARR, C. ROSALES, AND K. R. ROGERS. DETERMINANTS OF CHILDREN'S PESTICIDE EXPOSURE IN YUMA COUNTY, ARIZONA. Presented at International Society of Exposure Analysis, Tucson, AZ, October 30 - November 03, 2005.
Impact/Purpose:
The overall purpose of the Pesticides in Young Children - Border States program is to describe the relationship of health outcomes in children along the United States and Mexico border to repeated pesticide exposures via multiple sources and pathways. The current effort will conduct additional phase II studies and analyze the data to identify and address critical questions about three major areas: (1) the applicability of pesticide biomarkers for use as markers of exposure, (2) the predictive capability of quesionnaires for estimating exposure, and (3) identification of the most appropriate cohorts to be included in the Phase IIIb studies.
Description:
In 1999-2000, researchers from US EPA's Office of Research and Development in collaboration with several government and academic institutions conducted pesticide exposure assessment studies in Yuma county. Results from these studies have been previously reported (Gordon SM, et al J Expos Anal Environ Epidemiol 9 (1999) 456-470). One study was conducted in both urban and agricultural areas in Yuma county (Study 1). Urine samples were collected from 152 primary participants between four to seven years of age. Two additional studies limited to the agricultural intensive areas of Yuma county were conducted in two phases (Study 2, Stages 2 and 3). During phase one, 139 participants, ages two to six years, and 202 participants, ages one to four years, provided urine samples. House dust samples were also collected. Children with elevated dialkyl phosphate (DAP) urinary metabolites from each of the two studies (n=35-45) were selected to participate in the second phase consisting of a multi-media, multi-pathway exposure assessment.
Questionnaire responses from each of the five studies regarding pesticide use, parental occupation, dietary ingestion, and children's activities were analyzed using non-parametric comparison tests. Relationships between responses to specific questions and both DAP urinary metabolite levels were examined to determine the factors that resulted in significant differences. Pesticide use inside the home contributed to a significant difference in ethyl urinary DAP metabolite levels for several studies. Differences in children?s urinary DAP metabolite levels based on children's activities, geographic location, and timing of sample collection will be presented. Linear regression models that explain the variability in methyl and ethyl DAP and TCPy (chlorpyrifos specific metabolite) levels are presented.