Diffusion of organochlorine (OCPs) and cypermethrin pesticides from rohu (Labeo rohita) internal organs to edible tissues during ice storage: a threat to human health.

Abstract

The migration of organochlorine pesticides (OCPs) and cypermethrin residues from internal organs to edible tissues of ice-held Labeo rohita (rohu) was investigated in this study. The liver (246µg/kg) had the highest level of ∑OCP residues, followed by the gills (226µg/kg), intestine (167µg/kg), and muscle tissue (54µg/kg). The predominant OCPs in the liver and gut were endosulfan (53-66µg/kg), endrin (45-53µg/kg), and dichloro-diphenyl-trichloroethane (DDT; 26-35µg/kg). The ∑OCP residues in muscle increased to 152µg/kg when the entire rohu was stored in ice, but they decreased to 129µg/kg in gill tissues. On days 5 and 9, the total OCPs in the liver increased to 317µg/kg and 933µg/kg, respectively. Beyond day 5 of storage, total internal organ disintegration had led to an abnormal increase in OCP residues of liver-like mass. Despite a threefold increase in overall OCP residues by day 9, accumulation of benzene hexachloride (BHC) and heptachlor was sixfold, endrin and DDT were fourfold, aldrin was threefold, and endosulfan and cypermethrin were both twofold. Endosulfan, DDT, endrin, and heptachlor were similarly lost in the gills at a rate of 40%, while aldrin and BHC were also lost at 60 and 30%, respectively. The accumulation of OCP residues in tissues has been attributed to particular types of fatty acid derivatives. The study concluded that while pesticide diffusion to edible tissues can occur during ice storage, the levels observed were well below the allowable limit for endosulfan, endrin, and DDT.