Risk assessment of the exposure of insecticide operators to fenvalerate during treatment in apple orchards.

Dermal and inhalation exposure of the applicator to the insecticide fenavalerate in an apple orchard was measured for risk assessment during treatment. Emulsifiable concentrate (EC) and wettable powder (WP) formulations were sprayed using a speed sprayer (SS) or power sprayer (PS). Dermal patches, gloves, socks, and masks were used to monitor potential dermal exposure to fenavalerate, while personal air samplers with XAD-2 resins were used to monitor potential inhalation exposure. Validation of analytical methods was performed for the instruments' limit of detection, limit of quantitation, reproducibility, linearity of calibration curve, and recovery of fenvelerate from various exposure matrices. The results were encouraging and reasonable for an exposure study. Applicability of XAD-2 resin was evaluated with a trapping efficiency and breakthrough test. During mixing/loading, the amount of dermal exposure ranged from 262.8 μg (EC/SS) to 1652.6 μg (WP/PS) of fenvalerate, corresponding to ~0.0011-0.0066% of the total prepared quantity. In the case of WP, the amount of dermal exposure was 2032.3 μg (0.0081% of the total applied amount) for SS and 1087.9 μg (0.0145%) for PS after application. In the case of EC, the amount of dermal exposure was 3804.6 μg (0.0152%) for SS and 4055.0 μg (0.0541%) for PS after application. The primary body parts subject to exposure were thigh and upper arm for SS, and thigh and hand for PS. The amount of inhalation exposure with WP was 2.2 μg (8.65 × 10⁻⁶% of the total applied amount) for SS and 1.3 g (1.67 × 10⁻⁵%) for PS. The amount of inhalation exposure with EC was 2.5 μg (9.81 × 10⁻⁶%) for SS and 3.7 μg (4.97 × 10⁻⁵%) for PS. The absorbable quantity of exposure and margin of safety (MOS) were calculated for risk assessment. The MOS for all 4 cases was much greater than 1, indicating a low possibility of risk.