Effect of water treatment on mutagenic potential.

Enzymatic activation did not convert the compounds in the sample concentrates into mutagens. These results are in agreement with those of CHEH et al. (1979) that the mutagenic activity was two to three times greater without the activating system than with it. The dose response relationships demonstrated a low level of mutagenic activity for the concentrates of the Lake Michigan samples. The MAR increases for the completely treated potable water. The concentrates of the Calumet River water to which chlorine had been added produced more revertants per volume of concentrate than did the concentrates of water which had not been chlorinated. Chlorination of the water with no additional treatment produced the highest degree of activity. For the Calumet River samples, treatment with coagulants reduced the net number of revertants to one-third the value for the raw water. When chlorine was added as the final treatment step, the net number of revertants increased by a factor of ten.