By use of 18 varieties of pesticide and six of their breakdown products, experiments were conducted to cause mutation and reversion in S. typhimurium TA98 and TA100 within a range of 0.01ug-100 ug/plate.
The results showed that Captan had mutagenic effects on TA98 and TA100. However, when S-9 mix was added, the number of revertant colonies ceased increasing.
Ethylenthio urea caused mutations in TA98. When S-9 mix was added, revertant colonies increased about twice the number in the control. In the absense of S-9 mix, the result was the same.