Miki SANDA

Safety Evaluation by the Mutagen Formation Potential on Chlorination of the Shinano River Water

Toshiya KOMATSU@Shoichi FUJITA@Shuji HIMENO

The Shinano river water is used as a source for a tap water at many points. Because mutagens are contained in tap water, it is important to investigate the level of mutagenic precursor contained in the river water. The Mutagenic Formation Potential (MFP) on chlorination is the index of the content of mutagenic precursor.
In this study, MFP on chlorination of the Shinano river water was measured for evaluating the safety as a source for a tap water. The measurement was done at 8 points from October, 2001 to December, 2002 by Ames test using S. typhimurium strain TA100 without S9 mix. The mutagenicity values tended to be higher in autumn and winter. On the other hand, only a little variation was observed among the 8 points. Annual means at each point were ranged from 740 to 1,300 net rev. / L. Since average mutagenicity values in Japan are about 2,000 net rev. / L, risk level of Shinano river water is considered relatively low. In addition, the mutagenicity of 6 tap waters using Shinano river water was measured. Annual means at each tap water were ranged from 500 to 990 net rev. / L.