Evaluation of omethoate and fenitrothion absorption in greenhouse workers using protective equipment in confined areas

: Sprayers and workers engaged in manual operations in a greenhouse were monitored for exposure to omethoate and fenitrothion. Urinary dialkyl phosphates (dimethyl thiophosphate and dimethyl phosphate) were used as biological index of exposure to the two chemicals. Residues of fenitrothion on foliage were measured as well as levels of fenitrothion and omethoate in air samples collected in the breathing zone (personal sampling) and in the work-place near the entrance and the end of the greenhouse (static sampling). Skin exposure was estimated from pads placed on the thorax under overalls and from hand washing liquid at the end of the workshift. Sprayers wore respiratory and skin protection during the workshift. Workers engaged in manual operations did not wear respiratory protection. Re-entry to the greenhouse was permitted 48 h after spraying. Levels of omethoate and fenitrothion in air samples, on pads and on the hands, during manual operations on ornamental plants, were very low. Urine analysis shoved no significant difference between the pre- and post-exposure samples. No significant difference was found between levels of urinary dialkyl phosphates in the control group and exposed workers. Cholinesterase activity (acetyl and butyryl) showed no significant reduction at the end of the workshift compared with baseline values.