Mutagenicity evaluation of river waters in the NorthAmerica and Japan

点击翻译按钮获取中文摘要

The hanging technique using blue rayon, which specifically adsorbes mutagens with multicyclic planar structures, has advantages over the conventional method of bringing large volume of water back to the laboratoy for extraction. Therefore, the analysis of many samples from remote sites using the blue rayon hanging technique can be performed in a laboratory, although it has a disadvantage in terms of quantitative analysis. In this study, the blue rayon hanging technique was used to collect organic mutagens in river waters that flow through metropolitan areas in North America. Monitoring was performed at a total of 21 sites the Providence River (4 sites), the Charels River (2 sites), the Potomac River(6 sites), the St Lawrence River (5 sites), the Hudson River (3 sites), and the East River (1 site). Mutagenicity was evaluated by the Ames test using Salmonella strains TA98, TA100, YG1024, YG1041 and YG1042 with and without metabolic activation. The results demonstrated that strains YG1041 and YG1024 were much more sensitive than TA98 with S9 mix. Fourteen samples out of 21 were positive towards for YG1041 with S9 mix. Six samples among them gave 5,000 - 20,000 revertants per gram of blue rayon equivalent. YG1042 was also more sensitive than TA100. Eleven samples were positive in YG1042 with S9 mix. The highest activity was 10,300 revertants per gram of blue rayorfequivalent. The overall results showed that the water in rivers flowing through metropolitan areas contained some frameshift-type aromatic amine mutagens, although their mutagenicity was lower compared with river's data in Japan. Further studies were done to evaluate mutagenicity of river waters by blue-chitin column and Sep-pak CSP800 column. We conclude that both blue-chitin column and Sep-pak CSP800 column are efficient for quantitative assesment of mutagenicity of river waters and the blue rayon hanging method is the most convenient to assess mutagenic characteristics of river waters in remote areas.