Organochlorine pesticides in gallstones.

A method is described for the determination of organochlorine pesticide residues in human gallstones. The difficulty caused by the presence of large amounts of cholesterol in the stones is overcome by an acetylation step in the “clean-up” procedure, and the method finishes with identification and determination of the individual pesticides by gas-liquid chromatography. Results are given for 28 samples submitted by 2 hospitals, showing small amounts of dieldrin, p,p’-dichlorodiphenylethane (pp’-DDE), and benzene hexachloride (BHC) isomers to be commonly present in small amounts in gallstones. Some explanation for the presence of these residues in the stones is given. A case of suspected poisoning by these compounds showed an unusually large amount of dieldrin in the patient’s stones.