Abstract
Most drinking water contains suspected carcinogens such as trihalomethanes and other hazardous by-products. These are considered to be produced by chlorination of organic substances.
To screen carcinogenicity, bioassay methods using mammalian cells as well as microorganisms will be inevitably necessary. Thus, we examined the mutagenic activities of the drinking water by Ames test using S. typhimurium (TA100 and TA98) and chromosomal aberration test using cultured Chinese hamster lung cells (CHL/IU).
Drinking water from the Yodo River showed almost as high mutagenicity as chlorinated raw water and sewage effluent, and also the cell nuclei stained by fluorescent dye (Hoechst No. 33258) showed the chromatin condensation evoking DNA fragmentations, and eventually leading to chromosomal aberrations. These indicate apoptosis of the cells but not necrosis.
From the results revealed by the bioassay, the water quality was evaluated from the viewpoint of genotoxicity of drinking water for human health.
