Evaluation of Mexican American migrant farmworker work practices and organochlorine pesticide metabolites

Background Epidemiologic studies often must rely upon questionnaire data to assess past exposures. The ability of questionnaires to rank migrant farmw orkers according to past pesticide exposure is not known. Methods We conducted a pilot feasibility, study to measure a panel of 21 or ganochlorine pesticides (OCPs) and correlate levels with reported occupatio nal exposures in 26 Mexican-American migrant farmworkers in Baytown, Texas. The Migrant Farmworker Questionnaire developed by the National Cancer Inst itute (NCI) was administered and each participant donated a blood sample. T hree OCPs [mean (ppb) levels: mirex 1.8, DDT 1.0, and trans-nonachlor 0.7] were detected despite the fact that these chemicals have been banned in the US for many years, and the detected levels were far higher than the standa rd provided by, the referent laboratory. Work clothes, protective attire, a nd self-reported pesticide exposures were significant predictors of OCP exp osure. Similarly, personal hygiene, length of employment, and number of dut ies also predicted OCP exposure. Conclusions The results of this study indicate that data obtained from stan dardized questionnaires may be reasonable indicators of occupational exposu re when biomarker data are not available. (C) 2001 Wiley-Liss, Inc.