Pesticides in water and fish from rivers flowing into Lake Biwa (III)

Abstract
Surveys of seventeen organophosphorous pesticides were performed for water and fish samples obtained from seven rivers flowing into Lake Biwa in 1991. Seven pesticides were detected at high frequency for diazinon, IBP, fenthion and fenitrothion, and at low frequency for malathion, phenthoate and edifenphos in the water samples. The field data on accumulation and excretion of these pesticides by ayu sweetfish (Plecoglossus altivelis), pale chub (Zacco platypus) and dark chub (Zacco temminckii) were approximately consistent with their bioconcentration factors (BCF) and excretion rates calculated from the laboratory data on willow shiner. From these data, it has become apparent that the contamination of the fishes by these pesticides in the field can be approximately estimated from the laboratory data.