Occupational exposure to azinphos-methyl: Correlating biological markers to environmental residue levels

Peach harvester exposure to azinphos-methyl (AZM) residues estimated by the Transfer Factor (TF) ratio of Dislodgeable Foliar Residue (DFR) to Daily Dermal Exposure (DDE) was compared to estimates based on the relationship between dermal exposure and dialkylphosphate metabolite excretion. DFR was monitored in four orchards from the time of pesticide application through harvest. Eleven male harvesters wore cotton tee-shirt dosimeters and provided area-specific skin washes and wipes for DDE monitoring during work operations. Urinary dialkylphosphate metabolites of AZM were also monitored and compared to DDE results. During a later harvest for which DDE was not determined, the dermal exposure estimated by the TF (1,310 mug) was comparable to the estimates based on dialkylphosphate excretion (1,456-1,534 mug). A repeated measures ANOVA showed that harvesters' cholinesterase levels were significantly lower than 'non-harvesters'. No significant reductions in cholinesterase levels were detected over time.