Risk assessment of agricultural worker's exposure to fungicide thiophanate-methyl during treatment in green pepper, cucumber and apple fields

The present study was carried out to assess exposure and risk to thiophanate-methyl wettable powder for agricultural worker during mixing/loading and application with power sprayer in green pepper, cucumber and apple fields. Dermal exposure was measured with patches, gloves, socks and masks, while inhalation exposure was evaluated with personal air pump and solid sorbent. Those methods were full validated before experiment. During mixing/loading, dermal exposure amount in green pepper, cucumber and apple fields was 24.0±6.7, 4.5±1.5 and 18.5±0.6 mg, corresponding to mean 0.007, 0.001 and 0.005% of prepared active ingredient, respectively. The major exposed part for mixer/ loader was hands (78-92%). Dermal exposure amount for applicator in green pepper, cucumber and apple fields was 84.9±14.0, 34.0±20.8 and 30.7±9.1 mg, corresponding to mean 0.024, 0.016 and 0.013% of applied active ingredient, respectively. The main body parts of exposure in apple field were hands, while thighs and shins in other fields. Inhalation exposure amount in green pepper, cucumber and apple fields was 1.5±2.2, 52.7±48.9 and 4.0±4.9 μg during mixing/loading and 0.2±0.1, 23.2±12.4 and 0.4±0.6 μg for applicator, respectively. These results were suggested that main factors affecting dermal exposure were contact frequency to the plants, foliage density, hygienic behavior, work type, and working environment, while inhalation exposure was affected mainly by working environment, especially wind. In risk assessment, margin of safety for thiophanate-methyl in all cases was over 1. However, during application in green pepper field, margin of safety was close to 1.