Mutagenicity in the Surface Waters from Rivers in the UK and Japan from 1997 to 2005

抄録

Mutagenicity was monitored in the surface water from the river Thames in 1997, 2002, 2003 and 2005. All samples from the Thames taken at sites in London (a place close to Tower bridge and a site near Teddington lock) and in Windsor show significant mutagenicity in the Ames test. This suggests mutagenic pollution in the Thames was not improved from 1997 to 2005. Water samples from the Serpentine in Hyde Park, London and a sample from the river Dee in Chester also show mutagenic activities toward S. typhimurium YG1024. The mutagenicity (500-2500 revertants per liter) toward S. typhimurium YG1024 in the presence of metabolic activation found in the water from the Thames in London was comparable with that found in the water from the river Asahi in Okayama and the river Katsura in Kyoto, Japan in 2003 and 2005.
A comparison of the degree of mutagenicity was made between water samples from the Thames, Asahi and the Katsura rivers. Higher mutagenicity was observed with the O-acetyltransferase-overproducing strains, S. typhimurium YG1024 and YG1029, than with the parental strains S. typhimurium TA98 and TA100. This suggests the presence of amino- or nitro-groups in the structure of molecules polluting the water from all three rivers. Water samples taken from the Thames in 2002 and 2005 exerted mutagenicity in S. typhimurium YG1029, YG1024 and TA98 in the presence of metabolic activation but not in the absence of S9 mix, whereas samples from the Asahi and the Katsura showed mutagenicity in S. typhimurium YG1029, YG1024 and TA98 both in the presence and in the absence of S9 mix. This suggests that mutagenic pollution in the Thames and the Japanese rivers took place with different mutagenic contaminants.