Study On The Genetoxicity Of The Organic Pollutants In Drinking Water In Chongqing City

Water organic pollutants derive from various artificially synthesized organic substances. They are numerous in variety and quite different in nature. Many of them are proved to be harmful to human body even in extremely low level, such as mutagenicity, carcinogenicity, injury in reproductive and endocrinal system. Some water organic pollutants characterize in high biological enrichment and environmental retention which can exist in environment for very long time and be enhanced in toxicity in grade by food chain and result in severe damage to the health. Up to now, 2221 kinds of organic pollutants have been detected from the surface water. Some of them were proved to be carcinogen, cocarcinogen or mutagen. Since water organic pollutants usually act on human body co-operatively and a relativity exist between the genotoxicity and the carcinogenicity, examinating genotoxicity of water organic pollutants is routinely taken to assess its influence on human health.A population of 6 million live in the urban area of Chongqing. Drinking water mainly come from Yangtze and Jialing river. The pollutants of water environment result from industry is serious. Epidemiological study showed that. the mortality for liver cancer in urban Chongqing was higher than the average of that in China cities.Research on the risk factors of primary liver cancer in Chongqing showed that the three most relate risk factors had been the infection of HBV, the type of drinking water and the history for hepto-biliary disease. The pollutants ofwater is clearly one of very important factors that affect the health of Chongqing residents. And with the completion of the great Three Gorge project, Chongqing will be in the reservoir area. The situation of pollutants will be worse with the slowing down of the flow after the filling of great dam. Clearly, it is extremely important to study the relation between the drinking water and health of people in Chongqing.Solid phase extraction was used to extract the organic pollutants of source water and drinking water from 5 waterworks in urban area of Chongqing in three different water phases (spring, summer, winter). All water samples were examined with single cell gel electrophoresis (SCGE) to detect the DNA damage of rat primary cultured heptocytes by water organic pollutants. Water organic pollutants induced gene mutation and chromosome aberration in abundant season were tested by Ames test and micronucleus test (MNT). The protective role of green tea extraction on both the DNA damage in rat primary cultured heptocytes and chromosome aberration in mice polychromatic erythrocytes (PCEs) by water organic pollutants were observed with SCGE and MNT, and the level of malondialdehyde (MDA) in cell culture medium were assayed and protective mechanism was discussed. The main results were as followings:1. All the organic extraction which is from source water and drinking water in 5 waterworks in Chongqing can induced DNA damage in primary rat heptocytes. It showed that source water and drinking water in Chongqing had been polluted by organic substance. As for the distribution, the level of water organic substance in Shapingba and Yuzhongqu waterworks in which water is from Jialing river was higher than that in Heshangshan waterworks, Jiangnan waterworks and the waterworks of Southwest pharmaceuticals Co. in which the water was from Yangtze river. More DNA damage in primary cultured rat heptocytes can be induced by drinking water than source water except inShapingba waterworks. The degree of pollutants seemed to be follows: winter > spring > summer.2. The source water from Jialing river was seriously polluted, and the main pollutants were frame shift mutagens. The level of mutagen in Yangtze river was lower. Mutagenesis activity in source water from Jialing and Yangtze river was enhanced obviously after chlorination. The quality of drinking water is closely related that of source water. 3. The rate of MN in PCEs in mice were enhanced significantly by source water and dri...