Whole body dosimetry and risk assessment of agricultural operator exposure to the fungicide kresoxim-methyl in apple orchards

Abstract This study examined dermal and inhalation exposure of agricultural operators to kresoxim-methyl during pesticide mixing/loading and speed sprayer application (10 replicates, each of 3000 L of spray suspension) in an apple orchard and performed risk assessment. For the whole body dosimetry (WBD) exposure protocol, outer clothing, inner clothing, gauze, and nitrile gloves were examined to measure dermal exposure. In contrast, an IOM (institute of occupational medicine) sampler with a glass fiber filter was used to measure inhalation exposure. Analytical method accuracy in the exposure matrices was evaluated by a field recovery study. The dermal and inhalation exposure amounts for mixing/loading were 9.7 mg [0.002% of the total mixed/loaded active ingredient (a.i.)] and 1.2 µg (1.7 × 10 −6 % of the total mixed/loaded a.i.), respectively. The body parts more exposed were the forearms (35.5%), chest & stomach (30.2%), and hands (17.9%). During application, the dermal and inhalation exposure amounts were 66.5 mg (0.009% of the total applied a.i) and 34.8 µg (4.6 × 10 −5% of the total applied a.i.), respectively. The shins (18.5%) and chest & stomach (16.0%) were exposed to higher proportion of pesticide, followed by the thighs (15.8%) and back (14.7%). Comparing the exposure pattern as assessed by the WBD method in the present study with the patch method as in our previous study, the ADE (actual dermal exposure) as measured by the WBD method was 25 times less than that measured by the patch method. The daily exposure amounts of ADE and AIE (actual inhalation exposure) for mixing/loading were 711.8 µg/day and 4.3 µg/day, respectively, whereas the amounts of ADE and AIE for application were 1825.8 µg/day and 116.1 µg/day. In risk assessment of the mixing/loading and application scenarios, the AOEL (acceptable operator exposure level) of kresoxim-methyl was used as the reference dose to show that the RI (risk index) was much lower than 1, indicating that agricultural operators are at low risk of exposure to kresoxim-methyl.