Abstract
Eighty two wastewater samples which had met the Japanese conventional wastewater quality standards were collected to investigate their mutagenicity and the mutagen formation potential (MFP). Though the mutagenicity was detected from few samples, the MFP was detected from most samples. The highest MFP of 2.1 × 106 net rev. · l-1 was observed from a landfill leachate sample. Most of the MFP values observed from the wastewater samples were within the range of 1 × 103∼3 × 105 net rev. · l-1 which were 1∼300 times the mutagenicity level of the urban tap water in Japan, i.e., 1 × 103 net rev. · l-1. The highest MFP load of 1.9 × 1013 net rev. · d-1 was observed from the landfill leachate sample. Most of the MFP load values observed from the wastewater samples were within the range of 1 × 108∼1 × 1012 net rev. · d-1. It was concluded that a lot of wastewater causes significant adverse effect on the mutagenicity of tap water. Chemical industry wastewater, landfill leachate and sewage were remarkable as a considerable pollution source of the MFP of water sources for drinking water. Since the correlation between MFP and TOC, COD, BOD, A260, THMFP was weak, the MFP cannot be estimate from these conventional water quality indices.
