Reproductive Toxicology of 3,3',4,4'-Tetrachlorobiphenyl in Mice

Abstract

Environmental contamination by PCBs was first detected while screening environmental samples for DDT and related compounds. Since then, PCBs have been detected in almost every global environment including the Arctic and Antarctic. Accidental exposure of humans to PCBs has occurred in Japan and Taiwan. In both cases, the poisoning was a result of cooking rice in PCB-contaminated bran oil. It was believed that the symptoms derived from the poisoning were caused by contaminants of PCBs such as polychlorinated dibenzofurans. Studies however, have since detected the presence of 3,3{prime},4,4{prime}-tetrachlorobiphenyl, an extremely toxic PCB congener, as a component of the PCB mixture. The effects of PCBs on reproduction were first studied in the mink. Since then the reproductive toxicity of many commercial and PCB congeners have been assessed. Ronnback found no observable effect of 1.5 mg/kg and 15.0 mg/kg TCB administered as a single dose to pregnant mice on day 13 of gestation. Lucier et al. reported that no observable effect appears in animals when the compound is administered at less than 16 mg/kg/day. Studies have evaluated the effects of TCB on reproduction, but none have studied its effects throughout the entire gestation period of mice. This study was undertaken to evaluatemore » the effects of TCB on implantation, organogenesis, and embryogenesis in the developing mouse. 20 refs., 2 tabs.« less