Dermal and inhalation exposure to dimethoate.

Dermal and respiratory exposure and plasma acetylcholinesterase (ChE) activity were monitored on six workers spraying tomato crops under plastic houses with dimethoate [O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithoate]. The mean dermal exposure was 914 mg/day and the mean respiratory exposure was 17 mg/day. The maximum dose received by the spraymen was 18.2 mg/day. It was estimated that 84% of the dermal exposure was to the forearms and hands. Of the body areas monitored, the back of the neck received the least rate of exposure. The results also show a reduction in plasma ChE among spraymen. The mean difference was 37.1% less than the preexposure values, which exceeds the limits set by the World Health Organization.