中文摘要：

为了解干沟控制排水对地下水氮素污染的影响，于2012年8月至2013年7月，对利辛县车辙沟干沟控制区内的14个农田水位观测孔和13个农户水井，开展地下水位观测和各形态氮含量检测。在此基础上，对该区域地下水氮污染特征和健康风险状况进行分析与评估。结果表明：①研究区地下水N H4-N污染较为严重，而NO3-N和NO2-N则污染较轻，农田地下水的NH4-N、NO3-N、NO2-N和 TN平均浓度分别为0．49、2．10、0．028和3．56mg·L -1，农户井水平均值分别为0．22、0．93、0．030和1．37mg·L -1；②农田地下水N H4-N与NO2-N、NO3-N与T N浓度表现出相似的变化特征，而井水中NO3-N和T N变化特征基本一致；③饮水暴露途径和皮肤接触吸收暴露途径的氮危险指数平均值分别为3．73＆#215;10-2和3．10＆#215;10-4，均远低于可接受阈值1．0，对人体健康的影响可以忽略不计。

英文摘要：

To investigate the effect of controlled drainage on groundwater nitrogen pollution ,14 obser-vation wells and 13 farmers＇wells in the Chezhegou control drainage zone in Lixin County ,situated in Anhui Huaibei Plain （China） ,were chosen to observe underground water levels and determine differ-ent types of nitrogen concentrations periodically ,from August 2012 to July 2013 .And then ,ground-water nitrogen pollution features were analyzed and its health risks were evaluated for the study areas . Results show that ① pollution of ammonium nitrogen （NH4 -N） in groundwater is worse than that of nitrate （NO3 -N ） and nitrite （NO2 -N ） nitrogen ,and mean concentrations of N H4 -N ,NO3 -N , NO2 -N and TN in agricultural areas are 0 .49 ,2 .10 ,0 .028 and 3 .56 mg L -1 ,respectively ,while 0 . 22 ,0 .93 ,0 .030 and 1 .37 mg L -1 for residential areas ,respectively .② In agricultural areas ,similar change characteristics are shown for NH4 -N and NO2 -N concentrations ,and NO3 -N and TN con-tents ,whereas in farmers＇wells ,it is displayed between NO3 -Nand TN .③ The mean values of haz-ard indexes for oral and dermal exposure paths are 3 .73 ＆#215; 10-2 and 3 .10 ＆#215; 10-4 ,respectively ,far be-low the accepted threshed value 1 .0 .