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AGRICULTURAL HEALTH STUDY/PESTICIDE EXPOSURE STUDY: YEAR 1 MEASUREMENT RESULTS
Citation:
Thomas, K W., L S. Sheldon, S. M. Gordon, S. Reynolds, C. Lynch, AND M. R. Alavanja. AGRICULTURAL HEALTH STUDY/PESTICIDE EXPOSURE STUDY: YEAR 1 MEASUREMENT RESULTS. Presented at 11th Annual Meeting of the International Society of Exposure Analysis, Charleston, SC, November 4-8, 2001.
Impact/Purpose:
The primary goal of the AHS Pesticide Exposure Study (AHS/PES) is to measure exposure to applied pesticides for a subset of the cohort of private pesticide applicators and to provide data to evaluate exposure algorithms developed for exposure classification in the study cohort.
Description:
The Agricultural Health Study (AHS) is a prospective epidemiologic study of pesticide applicators and their spouses in Iowa and North Carolina. Exposure to targeted applied pesticides (2,4-D or chlorpyrifos) is being measured for a subset of applicators and their families in the AHS Pesticide Exposure Study to assess exposure classification procedures. Applicators are selected based on application methods and uses of personal protective equipment. Potential exposures are measured on one day of pesticide mixing, loading, and application (MLA) using dermal patch, hand wipe, and personal air samples. Urinary biomarker levels are measured in pre-and post-application samples from each applicator and for participating spouses and children. Samples extracts are analyzed by GC/MS or LC/MS. Questionnaires and observations of pesticide MLA activities provide information about work practices, use of protective equipment, and hygiene. Monitoring was completed for ten Iowa private pesticide applicators during the first year of the study (spring/summer of 2000).
Dermal samples were collected by placing ten cellulose or gauze patches on the body. The surface area of each patch was sized proportionately to the body area it represented. Patches were combined for extraction. Dermal patch measurement results ranged from 7 to 1100 ug/sample for eight 2,4-D applicators that used spray application methods, and 2 ug/sample for both chlorpyrifos applicators that applied a granular product. Hand wipe samples were collected using a sub-sampling technique that wipes approximately 10% of the hand surface area. Hand wipe measurement results ranged from 3 to 1400 ug/sample for the 2,4-D applicators while samples from the chlorpyrifos applicators contained less than the quantifiable limit of 1 ug/sample. Post-application levels of 2,4-D in urine ranged from 4 to 110 ug/g creatinine for 2,4-D applicators. Use of the target chemical on days before and after the monitoring day affected pre- and post-application urinary levels of 2,4-D for some applicators. Spouse and child urinary biomarker levels of 2,4-D ranged from 1.5 to 10 ug/g creatinine. Urinary levels of the 3,5,6-trichloropyridinol (TCP) metabolite of chlorpyrifos were 4 ug/g creatinine for the two chlorpyrifos applicators and the spouse of one of those applicators. Relationships between measured amounts, work practices, and the amount of applied active ingredient will be presented for the ten pesticide applicators monitored to date.
This work has been funded in part by the U.S. Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names of commercial products does not constitute endorsement or recommendation for use.