Monitoring the chronic effects of anticholinesterase pesticides in aerial applicators.

Four pilots were monitored over a six month period for physiological signs of anticholinesterase exposures in this preliminary study. Two pilots were controls and two were aerial applicators whose spraying activities included the application of ethyl parathion on more than 85% of their total acreages. Erythrocytic and plasma cholinesterase assays, plus dark-adapted pupil dilation, and a measure of the amplitude of respiratory sinus arrhythmia (RSA), were measured pre-seasonally and near the end of the spraying season. Comparisons between the controls and the two aerial applicators indicated that one aerial applicator displayed organophosphorus toxicosis symptoms. Dark-adapted pupil dilation and RSA more clearly indicated the chronic exposure than did the blood cholinesterase assays. The alleged exposure was linked by post-study interviews to flight pattern and residue cleaning procedures.