[The evaluation of the mutagenic activity of public drinking water by the Ames test]

The sources of potential mutagens in our environment are many, but the most important of these is water for public consumption. This is a result of the chlorinating process which is the main reason for the appearance of these mutagens. With this in mind, the aim of our study was to check a possible mutagenic activity, using the Ames test, in organic concentrates taken from water for public consumption in Madrid.

Several bacterial strains were used, namely Salmonella histidine dependent TA1535, TA1538, TA98 and TA100, taken originally from Salmonella typhimurium LT2. Each test was performed twice, with or without the introduction of the mammalian-microsome activation (S9 mix), as per the indications in Ames. The plate incorporation assay was used to test the mutagenicity. All samples of the water in question were processed and treated so as to create concentrates of organic chlorinated compounds.

The highest levels of mutagenicity appeared in the TA1535 strain and in the tests where the microsome fraction was not used (IM = 1.94).

With regard to mutagenic evaluation in organic concentrates taken from water for public consumption, no positive activity was found in any of the tester strains.