MONITORING PEACH HARVEST WORKERS EXPOSED TO AZINPHOSMETHYL RESIDUES IN SUTTER COUNTY, CALIFORNIA, 1991

Peach harvest workers were evaluated for exposure to azinphosmethyl re sidues by measuring foliar residues, urinary alkylphosphate metabolite s, butyrylcholinesterase (BChE), acetylcholinesterase (AChE), and derm al residues using clothing and skin washes. Workers entered orchards 5 1 days after application and worked in treated fields for 10 of the ne xt 17 days. Dislodgeable foliar residues ranged from 0.82 to 1.72 mu g /cm(2) and did not change significantly over the study period. Combine d mean dermal exposure for the 3 consecutive monitoring days was 32 mg and ranged from 17.9 to 60.5 mg. Overall mean excretion levels for th e 5 monitoring days were 1.7 mg dimethylphosphate and 1.9 mg dimethlyt hiophosphate. There was no significant difference in BChE between the exposed harvesters and minimally exposed sorters. The exposed group ha d significantly lowe AChE values than the sorters for 2 post-exposure blood draws by three testing methods, while no significant difference was found for the pre-exposure blood draw. the AChE values for the pos t-exposure blood samples for the exposed workers decreased significant ly about 10.20% over the 3-week exposure period but increased or remai ned constant for the sorters. Urinary metabolite excretion increased w ith continuous exposure and was inversely correlated with both AChE an d BChE but was not correlated with dermal exposure measurements. High correlations were generally observed between AChE measurements taken i n the field using a new spectrophotometric kit and laboratory AChE mea surements.