Comparative studies on tissue distributions of organophosphorus, carbamate and organochlorine pesticides in decedents intoxicated with these chemicals

This paper describes the tissue distributions of dichlorvos, an organophosphate, chlorpyrifos-methyl, an organophosphorothioate, methomyl, a carbamate, and endrin, an organochlorine, in three individuals (Cases 1-3) who died after ingesting insecticidal preparations containing these chemicals. In Case 1 involving dichlorvos and chlorpyrifos-methyl, no dichlorvos was detected in most of the blood and tissue samples. Tiny amounts of dichlorvos (0.067 mg/L and 0.027 mg/L) were detected in the vitreous humor and cerebrospinal fluid, respectively. The chlorpyrifos-methyl concentrations in the blood samples were very site-dependent with a range of 0.615-2.24 mg/L. The tissue concentrations of chlorpyrifos-methyl were within the range 0.379-8.60 mg/kg. The total amounts of dichlorvos and chlorpyrifos-methyl in the stomach were 879 and 612 mg, respectively. The serum cholinesterase activity was 3 IU/L/37 degrees C. In Case 2 involving methomyl, the methomyl concentrations in the blood samples were very site-dependent with a range of 0.56-4.75 mg/L. The tissue concentrations of methomyl were 2.61 mg/kg or less, no methomyl being detected in the spleen, liver and kidney. The methomyl concentrations in the cerebrospinal fluid and vitreous humor were 5.37 and 4.75 mg/L, respectively. The stomach contained 85 mg methomyl. The serum cholinesterase activity was 73 IU/L/37 degrees C. In Case 3 involving endrin, the victim underwent medical treatment for 7 h after ingesting an endrin preparation. The differences in the endrin concentrations among the blood samples were small, with a range of 0.353-0.615 mg/L. The tissue concentrations of endrin were within the range 0.467-13.3 mg/kg. The endrin in the stomach (66 mg) was adsorbed almost completely on the activated charcoal that was administered for medical treatment.