[Criteria of allowance for the mutagenic effectors in the Ames test]

Mutagenic activity of water pollutants on test-strains Salmonella typhimurium was studied. Results obtained from these studies were evaluated by the Dunnet method of multiple comparisons and the obtained data were compared with the value of excess of the colonies number in the experiment over control. The purpose of this comparison is to determine a ration of excess in the number of revertant colonies in the experiment above a control, under which a portion of the statistically significant results will constitute 90 per cent and more. Statistically significant results occur in 100% of cases when the number of revertant colonies in the experiment variants is 2.2 times as high as in control ones for strains TA 1535 and TA 1538, 2.0 times--for strain TA 98 and 1.8 times--for strain TA 100.