Acetylthiocholine (ATC) - cleaving cholinesterase (ChE) activity as a potential biomarker of pesticide exposure in the Manila clam, , of Korea

The acetylthiocholine (ATC) - cleaving cholinesterase (ChE) activity in Manila clam, which is widely distributed throughout the coastal environment of Korea, was assayed as a potentially useful biomarker of organophosphorous pesticides (OPs). A clear dose-response relationship was determined between inhibited ChE in adductor muscle of clams and four OPs (methidathion, chlorpyrifos, diazinon, IBP) which are heavily used OPs in Korea. The measured EC-24h values of methidathion, chlorpyrifos, diazinon, and IBP for were 7.16 μg l, 0.34 mg l, 3.01 mg l, and 3.41 mg l, respectively. In field studies, ChE activity in Manila clams collected from 23 stations in the mid-western coastal region demonstrated spatial variation with statistical differences. These results suggest that ChE activity in is a potential biomarker for assessing organophosphorous pesticide contamination in coastal environments.