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Clinical laboratory role in the evaluation of the patient exposed to acetylcholinesterase-inhibiting pesticides.

Ducatman AM; Moyer TP
American Association for Clinical Chemistry, Therapeutic Drug Monitoring, Continuing Education and Quality Control Program, 1982 Jul; :1-8
The role of the clinical laboratory in evaluating persons to acetylcholinesterase (AChE) inhibiting pesticides was discussed. The mechanism of organophosphate toxicity in humans was summarized. Studies have indicated that the toxicity of organophosphates is due primarily to inhibition of AChE at nerve synapses as a result of a reaction with a serine residue at the AChE catalytic center. Erythrocyte AChE activity reflects this inhibition directly. Plasma cholinesterase (ChE) activity indirectly parallels AChE activity under most circumstances. Environmental and biological monitoring of organophosphate and carbamate exposures was discussed. Environmental monitoring based on breathing zone sample and plant and soil residue analysis was considered necessary to establish that the work environment is safe. Biological monitoring of human serum or erythrocyte AChE served as a quality control measure for primary safety procedures. Biological monitoring can be used to confirm heavy exposure, to follow the progress of recovery, or to assist in return to work decisions. Determining human AChE should not be used as the primary means of safety assurance. The limitations of biological monitoring were discussed, including problems in establishing baseline levels of enzyme activity, AChE activities not having decreased to steady state values before symptoms of organophosphate poisoning develop, and the inability of AChE monitoring to effectively detect exposure to some ChE inhibiting agents such as carbamates. Handling blood samples for AChE assays was discussed. Methods for determining erythrocyte AChE and plasma ChE were reviewed. The metabolism of organophosphates was discussed. Chronic and subclinical effects of organophosphates and carbamates were considered. Delayed neurotoxicity was described. The authors conclude that biological monitoring of AChE activity has a major role in preventing exposure to organophosphate pesticides.
NIOSH-Grant; Training; Clinical-chemistry; Enzyme-activity; Organo-phosphorus-pesticides; Cholinesterase-inhibitors; Biological-monitoring
Environmental Health University of Minnesota 1158 Mayo Memorial Minneapolis, Minn 55455
Publication Date
Document Type
Final Grant Report
Funding Amount
Funding Type
Fiscal Year
Identifying No.
Grant-Number-T15-OH-007098; Grant-Number-T42-OH-007098
NIOSH Division
Priority Area
Source Name
American Association for Clinical Chemistry, Therapeutic Drug Monitoring, Continuing Education and Quality Control Program, pages 1-8
Performing Organization
University of Minnesota of Mnpls-St Paul, Minneapolis, Minnesota
Page last reviewed: February 18, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division