[Male reproductive toxicity of polychlorinated biphenyls].

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants with estrogen-like effects that exist widely in the environment, and its male reproductive toxicity is arousing more and more attention. Studies indicate that different types of cells in the testis respond differently to PCBs exposure. This article presents an overview on the toxicity of PCBs to testicular germ cells, Leydig cells, Sertoli cells and male offspring. We suggest that deeper studies focus on the mechanism of PCBs according to the results of investigations on male reproductive epidemiology. An insight into the intercellular junctions of Sertoli cells might produce a breakthrough in the studies of the testicular toxicity of PCBs.

Application of a new bioassay technique using goldfish for assessment of water toxicity.

There are a variety of chemicals in aquatic environment, so it is important to assess the toxicity. The biomarkers such as induction of DNA damage, micronuclei, vitellogenin, and hepatic P450 in fish are known to be effective for monitoring genotoxic and/or estrogenic chemicals. However, there is little study to use these biomarkers in same fish. Goldfish (Carassius auratus) is widely used and is suitable in size to collect blood or organs. In this study, validity of multiple-biomarkers in goldfish was checked using standard chemicals and applied in the river water. Ho River, which flows through the textile dyeing factory in Shizuoka Prefecture, Japan, was reported to show genotoxicity toward Salmonella typhimurium TA98 and YG1024. When the goldfish were exposed to Ho River, DNA damage, estrogenic activity, and CYP1A induction were observed. Through the study, it was assumed that not only mutagens/carcinogens but also endocrine disrupting chemicals and poly aromatic hydrocarbons were present in Ho River. Therefore, chemical identification should be required. We could evaluate both genotoxicity and estrogenic activity simultaneously, so goldfish might be a good experimental model for estimation of chemical contamination levels in aquatic environment.

[PCBs concentrations in human milk collected from a polluted area--exposure risk for feeding infants].

OBJECTIVE: To determine the concentration of PCBs and the distribution of dioxin-like compounds in human milk collected from a polluted area where discarded electronic equipment is dismantled, and to evaluate the risk for feeding infants. METHODS: The authors collected 20 and 12 milk samples from the polluted area and nearby town, respectively. Milk samples were analyzed for total PCBs (t-PCBs) by gas chromatography, and two mixed milk samples from the two areas were detected the distribution of dioxin-like compounds. RESULTS: t-PCBs in human milks of polluted area and control area were 0.39 - 3.92 microg/g fat and 0.46 microg/g (only one sample was detectable), respectively. The TEQ of PCB126 contribute to total TEQ of dioxin-like compounds was similar to other countries and regions. The TEQs of PCBs of the polluted and control area were 59 pg/g fat and 6 pg/g fat, respectively. CONCLUSION: The TEQ of PCBs of polluted area was much higher than other countries and regions, and the dioxin-like compounds intake of infants was much higher than the Tolerable Daily Intake (TDI) for dioxin recommended by WHO.