Seasonal and Basinal Variations of Mutagenicity of River Water

Seasonal and basinal variations of mutagenicity of Sagami River water were investigated for one and half year with blue cotton, which is a selective adsorbent for Salmonella typhimurium TA98 sensitive mutagens, and the variations were compared with those of known water pollution indicators. Adsorbates on blue cotton from Sagami River water showed mutagenicity toward TA98 strain in the presence of S9 mix, suggesting the occurence of indirect mutagens in water tested. The mutagenicity depended on season and basin of sampling. Adsorbates in the upper stream showed relatively high mutagenicity in winter but not in summer, while those in the lower stream showed less mutagenicity in all season. No significant correlation was found between variations of mutagenicity and those of water pollution indicators, such as coliform group, potassium permanganate consumed, BOD, electric conductivity and anionic surfactant. These facts suggest that mutagenicity of river water cannot be predicted with known water pollution indicators. New type of pollution indicator with bio-system such as mutagenicity test may need to monitor the safety of water.