The micronucleus assay in Anodonta cygnea for the detection of drinking water mutagenicity.

A micronucleus test in gill cells of the freshwater mussel Anodonta cygnea has been proposed for the detection of drinking water genotoxicity. Animals were exposed for 28 days to a drinking water sample and collected every week. Highly significant increases in spontaneous MN frequency were observed at each sampling, especially after 13 days of exposure. As positive control 2 doses of mytomicin C (MMC) were used (10(-8) and 10(-7) M). A second experiment was performed at a municipal waterworks in order to assess the role of water treatment processes in the production of mutagenic compounds. The most prevalent genotoxic effects were detected after chlorination (mean: 10.47% +/- 3.05, p less than 0.001).