Evaluation of hepatic and renal effects of acute and subacute oral exposure to bromochloromethane in rats.

Bromochloromethane (BCM) is a disinfection byproduct (DBP) formed in drinking water when oxidizing disinfectants (i.e., chlorine) react with natural organic matter. BCM is structurally analogous to other DBPs, such as chloroform and bromodichloromethane, that have human health effects, specifically hepatic or renal toxicity. Given the lack of robust studies in rodents and the structural similarity of BCM to known liver and kidney toxicants, the current study was designed to examine the potential for hepatotoxicity or nephrotoxicity from either acute or subacute oral exposure to BCM in male and female Fischer 344 rats. Biomarkers of liver and kidney injury were evaluated in serum and urine samples. In the acute exposure study to 1000 mg/kg body weight BCM, there was little evidence of liver or kidney toxicity. In the subacute exposure studies to 1000 mg/kg body weight BCM, lethality occurred in both male and female rats following multiple oral doses. In the subacute exposure to 750 mg/kg/day BCM, there were only temporary changes to hepatic biomarkers in females, and there were no histological changes observed. These oral gavage studies indicate that BCM is less toxic to the liver and the kidney relative to their structural analogs.