| Drinking water is an indispensable part of human life. However, the quality of drinking water are under the effects of pollutants from industrial, agricultural production and domestic sources. It was investigated that the water quality had a tendency to decrease in most of water sources in Jilin Province. Pesticides as one of the major pollutants have a long-term and cumulative effect on the quality of drinking water. Atrazine(ATR) had been detected in the water body of Jilin Province, as it was detected in other waters around world, and the concentration of which were above the standard in part of them. Yet the pollution level of ATR and its effects on mammals were not known clearly.This research is designed to make clear the concentration and variation of pollutants including ATR, COD and other conventional pollutants in water source and agricultural runoff catchment areas, and observe the effects of rats exposed to ATR in subacute and low-dose,long-term pattern, and discuss its possible mechanism. Then, the proposal of more frequency for ATR in routine monitoring of drinking water quality can be get by analysized the relevance between ATR and COD.Three typical Community drinking water source and one farmland around the water source(including longitudinal slope, lateral slope and flat field) were chosen based the production and planting area of corn and sorghum.The concentration of ATR and other pollutants were get by monitoring lasted from May to September. The relevance between the water quality and pollutions were assessed by correlation coefficients. A biological toxicity test on subacute exposure(Wistar rats oral exposure for 28 days) and low-dose, long-term exposure(Wistar rats oral drinking freely for 180 days) were made according to the detected concentration of ATR and index. For further understanding of the molecular mechanism of organic oxidative-antioxidative reaction, serological methods was adopted to assess the functional changes of heart, liver and kidney, Biochemical and immunological methods were adopted to assess the oxidative stress reaction in the homogenate of heart, liver and kidney.The results are showed as follows:(a) ATR was detected from surface community drinking water in middle city where is abundce corns.acorrding to the water quality standard.The concentrations of ATR in three water source were all below the limit of 0.003mg/L, except one sample exceeded the standard.The water quality of Xinlicheng and Yangmu reservoir can reach class Ⅲ except concentration of Volatile phenol ATR is above class Ⅲ,and the average of water quality of Langjiazi reservoir can meet the class Ⅱ in nonmal season and rainy season. The agricultural runoff nearby Yangmu Reservoir, ATR was above the standards and the maximum reached 0.0322mg/L. The average concentration of water quality of Xinlicheng reservoir were between the classⅡand class Ⅲ, and the concentration of volatile phemol was above classⅢ in nonmal season and rainy season, as the same as the water quality of water quality of Yangmu reservoir except p H and concentration of ATR, and the average of water quality ofLangjiazi reservoir can meet the classⅡin the same season. The average concentrations of ATR water quality from three sort agricultural runoff were above the community drinking water quality. The concentration of water quality from lateral slope was above classⅤ, and the water quality from the longitudinal slope can reach class Ⅳ, the water quality from flat field can reach class Ⅲ.(b) There is no relevance between COD and ATR in drinking water source and farmlands catchments. The water quality of Yangmu Reservoir had effected by the agriculture pollution resource hardly.(c) The exposure dose at 5mg/Kg, 25mg/Kg and 125mg/Kg and the dose of cumulative tests at 80μg/L, 400μg/L and 2 000μg/L were determined.NO evident changes of MDA and NO were observed in heart and liver under the subacute exposure, but MDA and NO changes was obvious observed in kidney. And SOD, catalase and glutathione peroxidese had no evident changes in heart, yet they decreased obviously in kidney and liver. The expression of HO1 and NQO1 had no changes in heart but decreased obviously in kidney and liver, which implied that the above dose of ATR exposure for 4 weeks could cause oxidative injuries in kidney. No significant differences of expressions of Nrf2 and Keap1 was observed in heart in all exposed groups, but in kidney an increased expression of Nrf2 and a decreased expression of Keap1 were both observed with nuclear transfer. The above implied that the active oxygen produced by ATR activates Nrf2 pathway and induces the expression of phase II detoxifying enzyme and anti-oxidase to produce an anti-oxygen function.Either subacute expouse(28days) or chonic accumulations(180days) of ATR, it is not positive result for wistar rats, used the Community drinking water source as drinking water.subacute exposure of ATR can affect the metabolic function of liver and excretory function of kidney and has no influence to heart. Oxidative stress may be the underlying mechanism. The organs can defense the oxidative damage through Nrf2-ARE pathway. Low-dose and long-term exposure may damage the functions of damage yet its damage to heart and liver was not observed. The variety of ATR’s influence to different organs may be a result of its distribution, metabolism and excretion. In long-term cumulative exposure group, changed of myocardial enzyme and transaminase in serum was not observed while the level of urea nitrogen and creatinine increased obviously. Pyknosis was observed in liver cells and edema was observed in renal tubular epithelial cells, which implied that low-dose and long-term exposure could cause damage to liver and kidney.Some certain concentration of ATR can be detected in surface drinking water source among the middle of Jilin province where is the main agricultural resources for gain production.The monitoring action for drinking water source of Jilin province can be adjusted slight according the result from this study, and it is the example for prevention of low concentrations of toxic action of atrazine. At the same time, the results can support the study on environmental criteria efficiently. |
