Worker exposure to, and absorption of, cypermethrin during aerial application of an “ultra low volume” formulation to cotton

Agricultural pilots and mixer-loaders were monitored for dermal exposure to and absorption of, the insecticide cypermethrin during aerial “ultra low volume” (ULV) applications in vegetable oil to cotton. Pilots were monitored for dermal exposure and mixer-loaders were monitored for exposure and systemic absorption. All mixer-loaders wore protective equipment. Potential (protected and exposed skin) exposure was 1.07 (0.26 to 2.65) mg/8 hr for pilots and 10.5 (2.50 to 23.1) mg/8 hr for mixer-loaders. Actual (exposed skin only) exposure was 0.67 (0.08 to 2.08) mg/8 hr for pilots and 2.43 (0.22 to 5.27) mg/8 hr for mixer-loaders. The exposure of pilots was predominantly of the hands, whereas that of mixer-loaders was more uniform, since their hands were protected by gloves.Absorption by mixer-loaders, determined by analysis of urinary metabolites, was 46 to 78 μg cypermethrin equivalents per 3 mix-loads and 12 simulated mix-loads, respectively. This is a very small proportion of their predicted exposure levels, as measured in different mixer-loaders.This study demonstrates that exposure of pilots and mixer-loaders during aerial ULV applications of cypermethrin is minimal and that absorption of the chemical is only a very small proportion of that contacting the skin.