Genotoxicity of drinking water from three Korean cities

Organic content of drinking tap water from Seoul, Taejon, and Suwon was ext racted with an XAD-2 resin column and organic solvents. Four doses of the e xtract equivalent to 4, 2, 1, and 0.5 1 water were tested for mutagenicity in Salmonella typhimurium strains TA98 and TA100 in the presence and absenc e of S9 mix. The organic extracts of the water from all three cities were m utagenic in TA 98 without S9 mix and in TA 100 with and without S9 mix. The highest number of revertants per plate was found in the absence of S9 mix. Three doses of the extract (equivalent to 22, 11, and 3.7 1 water) were al so tested in the bone marrow micronucleus test using BDF1 mice. At the high est dose, a significant increase of the micronucleus frequency was observed . The time required to be on the effect, however, varied with the source of the water. Our results indicate that the drinking tap waters from the thre e cities were genotoxic clearly in the bacterial test and also in the in vi vo assay with mice. As we found no genotoxicity of the source water as seen in a previous study, it is likely that the chlorination process leads to t he genotoxicity of the tap water. (C) 2000 Published by Elsevier Science B. V. All rights reserved.