Genotoxicity of blue rayon extracts from river waters using sister chromatid exchange in cultured mammalian cells.

Using cultured Chinese hamster lung (CHL) cells, sister chromatid exchange (SCE) assays were carried out with blue rayon extracts recovered at seven sampling locations from the Katsura, Nishitakase and Kamo Rivers, tributaries of the Yodo River, in Kyoto City, Japan. The downstream extracts of wastewater treatment plants showed higher SCE frequencies than the upstream extracts both with and without metabolic activation, suggesting that the effluents from wastewater treatment plants were the possible pollution sources of genotoxic chemicals in the rivers. The results show the possible use of SCE in CHL cells for the monitoring of genotoxicity of blue rayon extracts from river waters. In addition, simultaneous treatment with sodium thiosulfate significantly reduced the frequencies of SCE induced by blue rayon extracts.