Monitoring of pesticide chlorpyrifos residue in farmed fish: investigation of possible sources.

Chlorpyrifos, a widely used organophosphorus insecticide having many urban and agricultural pest control uses, is one of the major pesticides detected in Taiwan fishery products. Whereas previous studies examined, this study explored possible sources of chlorpyrifos residue, particularly in farmed fish. Eight hundred fourteen samples of marketable fish were analyzed for chlorpyrifos residues. One hundred thirty-seven samples contained detectable residues, and farmed fish showed higher detection rates (23%) than wild fish. Based on the findings of all media of the eleven aquiculture farms, the existence of chlorpyrifos in the farmed fish were positively related to existence in fish feed. A study of indoor carp confirmed dietary accumulation of chlorpyrifos.