In Depth Biochemical, Pharmacological and Metabolic Studies on Trihalomethanes in Water.
Bull-RJ; Robinson-M; Brown-TJ; Mink-FL; Lingg-RD; Whitmire-C
The risks associated with the occurrence of chloroform (67663) and other trihalomethanes in drinking water were examined by in depth biochemical, pharmacological, and metabolic studies. Osborne-Mendel- rats and B6C3F1-mice were exposed to doses of chloroform in drinking water ranging from 0 to 2700 parts per million; animals were sacrificed at 30, 60, or 90 days for chemical analyses (serum glutamate-oxalacetate-transaminase, lactic-dehydrogenase, blood urea nitrogen, serum glutamate-pyruvate-transaminase, and serum triglycerides). Tumors and lesions were examined microscopically. For the metabolic studies, animals were dosed with radiolabeled chloroform by intragastric intubation; feces, urine, and expired air were sampled at various time intervals, and radioactivity in selected tissues and organs determined. Results indicated a decrease in the level of enzymes classically found in serum following acute liver injury. Mice appeared much more sensitive than rats to the development of fatty liver. Histopathological evidence of fatty infiltration of the liver was observed in the mice at all sacrifice periods of the subchronic study. The authors conclude that the data supports the contention that the ability of chloroform to produce liver tumors is not separable from its ability to damage the liver.
Laboratory-animals; Chloromethanes; Biochemical-analysis; Drinking-water; Chlorinated-hydrocarbons; Metabolic-study; Liver-damage; Liver-enzymes;
Proceedings of the First NCI/EPA/NIOSH Collaborative Workshop: Progress on Joint Environmental and Occupational Cancer Studies, Rockville, Maryland, May 6-8, 1980