Mutagenicity study of water samples from a waterworks taking Yangtze River as its water source in Jiangsu Province

OBJECTIVE: To understand the occurrence and change of mutagencity of water samples in the process of drinking water treatment and distribution in a waterworks taking Yangtze River as its water source in Jiangsu Province. METHODS: Large volume of inlet water, finished water and tap water samples were extracted by XAD-2 resin. Mutagencities were assessed by Ames test and a mutation ratio( MR) of 2 or greater was judged as a positive result. RESULTS: Compared with the samples with S9, samples without S9 presented more positive results( P = 0. 005). That water treatment elevated MR values( P = 0. 007) while the pipe transport made MR values down( P = 0. 038) was observed in samples without S9. The tap water showed weaker mutagenicities than the raw water in samples with S9( P = 0. 008). Compared to the raw water samples, the finished water samples showed more positive results(-S9) and lower MR values( + S9, P =0. 002). CONCLUSION: Significant mutagenicities of water samples from the Yangtze Riverand its processed water were presented, and frame shit and direct mutagens deserved special concern.