Development and application of quantitative methods for monitoring dermal and inhalation exposure to propiconazole

Abstract

Quantitative methods to measure dermal and inhalation exposure to the fungicide propiconazole were developed in the laboratory and applied in the occupational exposure setting for monitoring five farm workers’ exposure during pesticide preparation and application to peach crops. Dermal exposure was measured with tape-strips applied to the skin, and the amount of propiconazole was normalized to keratin content in the tape-strip. Inhalation exposure was measured with an OVS tube placed in the worker’s breathing-zone during pesticide handling. Samples were analyzed by GC-MS in EI⁺ mode (limit of detection 6 pg µl⁻¹). Dermal exposure ranged from non-detectable to 32.1 ± 22.6 ng per µg keratin while breathing-zone concentrations varied from 0.2 to 2.2 µg m⁻³. A positive correlation was observed between breathing-zone concentrations and ambient air temperature (r² = 0.87, p < 0.01). Breathing-zone concentrations did not correlate with dermal exposure levels (r² = 0.11, p = 0.52). Propiconazole levels were below limit of detection when rubber gloves, coveralls, and full-face mask were used. The total-body propiconazole dose, determined for each worker by summing the estimated dermal dose and inhalation dose, ranged from 0.01 to 12 µg per kg body weight per day. Our results show that tape-stripping of the skin and the OVS can be effectively utilized to measure dermal and inhalation exposure to propiconazole, respectively, and that the dermal route of exposure contributed substantially more to the total dose than the inhalation route.