Field Group - Pesticides

Farmworker Exposure to Pesticide Residues During Apple Thinning

The purpose of this study was to characterize worker exposure to azinphos-methyl over an entire apple thinning season. Three farm sites and 20 workers were recruited for the study. Exposure potential was estimated by measuring residue on leaves, and individual exposures were estimated by measuring urine metabolites and enzyme activity. Measurable levels of guthion (dimethyl thiophosphate or DMTP) residues were found on apple leaves throughout the six-week sampling period. Measurable metabolites of guthion were found in virtually all urine samples collected from workers at the three study sites. Mean guthion concentrations among all thinners were significantly higher than reference workers. This study demonstrated that measurable guthion residues are present on pesticide-treated apple foliage in the Wenatchee region of Washington State throughout a typical thinning season, and that contact with residues on leaves results in low but measurable daily pesticide absorption for workers conducting thinning activities.

Simcox NJ, Camp J, Kalman D, Stebbins A, Bellamy G, Lee IC, Fenske R. Farmworker exposure to organophosphorus pesticide residues during apple thinning in central Washington State. Am Ind Hyg Assoc J. 1999 Nov-Dec;60(6):752-61.

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Biological Monitoring of Organophosphorous Pesticide Exposure Among Children of Agricultural Workers

Children living with pesticide applicators were monitored for increased risk of pesticide exposure. Urine samples were collected from 88 children, with repeated measures 3-7 days apart. Guthion (dimethyl thiophosphate or DMTP) metabolite levels were significantly higher in applicator children than in reference children. Applicator children living less than 200 feet from an orchard were more likely to have DMTP in their urine than applicator children who lived farther away. A marginally significant relationship between exposure and potential track-in from wearing work shoes in the home was found. These results confirm that applicator children experience higher exposure levels than children in the reference population.

Loewenherz C, Fenske RA, Simcox NJ, Bellamy G, Kalman D. Biological monitoring of organophosphorus pesticide exposure among children of agricultural workers in central Washington State. Environ Health Perspect. 1997 Dec;105(12):1344-53.

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Organophosphate Pesticide Exposure of Children Residing in Non-agricultural Communities

The objectives of this study were to: 1) develop a profile of organophosphate pesticide exposures in children residing in non-agricultural communities in western Washington using urinary dialkyl organophosphate metabolite concentrations as a measure of exposure, and 2) examine the relationship of exposures with age, gender, socioeconomic status, season, and pesticide use in and around the house. Study results indicated no variation in organophosphate pesticide exposure related to season, age, or gender. Additionally, there was no consistent association with residential pesticide use or organophosphate exposure. Findings suggested an association with organophosphate exposure and the geographic location of a child’s residence. The exposures identified in the populations did not appear to pose an acute health risk.

Lu C, Knutson DE, Fisker-Andersen J, Fenske RA Biological monitoring survey of organophosphorus pesticide exposure among pre-school children in the Seattle metropolitan area. Environ Health Perspect. 2001 Mar;109(3):299-303.

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