Detection of mutagenicity in drinking water using a micronucleus test in newt larvae (Pleurodeles waltl).

We have previously described a micronucleus test using erythrocytes from larvae of the urodele amphibians Pleurodeles waltl (pleurodele) and Ambystoma mexicanum (axolotl). The test is based on a comparison of the levels of micronucleated erythrocytes in blood smears from larvae reared in water containing a clastogen, with the levels from larvae reared in purified water. Using larvae from the pleurodele, we have employed this test to evaluate mutagenic activity in drinking water. Groups of larvae were reared in tap water, while control groups were reared in tap water which had been filtered over sand and active carbon to remove micropollutants. Seven separate tests carried out between October 1985 and May 1986 all gave positive results of varying degree depending on the time of year. This test is therefore able to detect clastogens in normal drinking water. It could be used for quality control of drinking water during the various stages in the treatment of raw water without any requirement for prior extraction or concentration of micropollutants.