江南Z市农村饮水有机污染物健康风险评估

Assessment Health Risk to the Rural Drinking Water Organic Pollutants of Z City at South of the Yangtze River

应用化学法及吹扫捕集、气相色谱-质谱联用仪(GC-MS),检测Z市农村不同类型饮用水与癌症相关的有机污染物,对污染物的剂量与癌症标化死亡率进行Spearman等级相关分析。该市河水、池塘水、浅井水中部分样品的COD Mn、BOD5和NH3-N指标超过地表水环境质量Ⅲ类标准,微生物指标超过生活饮用水卫生标准,检出NH3-N及NO3-N、NO2-N合成致癌物NAD的2类前体物及NDMA等直接致癌物。Z市农村河水、池塘水、浅井水主要受生活排污和农业生产污染,不宜作生活饮用水。不同类型饮用水有机污染物丰水期高于枯水期(P值均小于0.05)。癌症标化死亡率与不同类型饮用水有机污染浓度呈等级正相关(P值均小于0.05),与NO2-N、NDMA、NDEA含量呈剂量-效应关系。直接饮用污染的地表水是造成该市农村癌症高发聚集分布的主要原因之一。

The levels of chemical pollutants in different type drinking water,which lead to rural cancers high incidence clusters distribution,were determined with analytical chemical methods and the trap （P＆T） and gas chromatography-mass spectrometry （GC-MS） instrument.Relationship of levels of chemical pollutants dose and cancer standardized mortality was tested with Spearman rank correlation.The results of the water quality tests showed that the CODMn,BOD5 and NH3-N levels in some of water samples from river water,pond water,and shallow well water exceeded the Chinese Class Ⅲ surface water standards.The microorganism indicators exceeded the drinking tap water criteria.NH3-N and NO3-N,NO2-N,which are the two types of precursors to synthetic NAD,and the NDMA and other direct carcinogen were tested.Thus it can conclude that river water,pond water and shallow well water in Z city rural can＇ t server as drinking water or dinking water sources.The pollutions of different types of drinking water in wet season were higher than that in the dry season （P ＜ 0.05）.The relationship between agestandardized cancers mortality and levels of drinking water pollutions dose in drinking water were positively correlated with grade （P ＜ 0.05）.Total cancers mortality showed a dose-response trend with NO2-N,NDMA,or NDEA concentration in some villages.Direct drinking contamination surface water is one of the main reasons led to the high cancers incidence and clusters distribution of the City rural.