Evaluation of coumaphos exposure among tick eradication workers.

Abstract

To evaluate both the cholinesterase monitoring program and newer field methods of determining coumaphos exposure among tick eradication workers. Measured blood cholinesterase by the Ellman and field testing methods and tested urine for chlorferon pre- and postshift; conducted personal air sampling, patch sampling of clothing, and wipe sampling of hands for coumaphos. Fifteen workers had normal plasma cholinesterase and acetylcholinesterase levels. No significant changes occurred pre- to postshift. High correlation was found between plasma cholinesterase and acetylcholinesterase levels by field testing and Ellman methods (r = 0.91, P < 0.01 and r = 0.63, P < 0.01, respectively). Chlorferon levels rose 4 to 6 hours after use (P < 0.01). Airborne coumaphos was detected in only one sample, in a trace amount. The majority of patch and hand wipe samples detected coumaphos. Dermal exposure to coumaphos resulted in significant increases in urinary metabolites of coumaphos.