中文摘要：

在作物生长期、收获期和收获后采集土壤、地下水和蔬菜样品,探讨癌病高发区土壤硝态氮对地下水和蔬菜硝酸盐积累的影响,以及由此引发的健康风险.结果表明,氮肥施用和灌溉是造成沿岸土壤、地下水和蔬菜硝酸盐积累的主要原因.受到河流氮污染影响,灌溉用水中氨氮和硝态氮经过灌溉-蒸发和淋溶过程的反复交替,向土壤和地下水迁移,引起土壤、地下水和蔬菜硝酸盐的积累.紧邻沙颍河的癌病高发村庄,土壤、地下水以及蔬菜硝态氮积累均明显高于全区平均水平.土壤在作物生长期和收获后分别达到149.01 mg·kg^-1和31.70 mg·kg^-1,其中多年菜地土壤硝态氮积累最为突出,分别达到276.44和68.26 mg·kg^-1.作物生长期地下水硝态氮平均含量达38.32 mg·L^-1,超标近3倍,叶菜类蔬菜硝酸盐平均含量高达3269.04 mg·kg^-1,超出允许含量1倍以上.癌病高发村庄居民存在突出的饮水和蔬菜硝酸盐暴露健康风险.

英文摘要：

Samples of soil,ground water and vegetable were collected during the crops＇ growth period,harvest period and post-harvest period in a high cancer incidence area. The influence of soil nitrate-N on nitrate-N accumulation in ground water and vegetable,and the corresponding health risks were explored in this paper. The results showed that nitrogen fertilizer application and irrigation were the main causes leading to the excessive nitrate accumulation in the banks soil,ground water and vegetables along the river. Due to heavy pollution of the river,ammonia nitrogen and nitrate nitrogen in irrigation water alternated repeatedly through irrigation,evaporation as well as eluviation,migrated continuously into soil and ground water,and caused the nitrate accumulation in soil,ground water and vegetables. The average soil nitrate-N was 149.01 mg·kg-1in crop growth period and 31.07 mg·kg^-1in post-harvest period,which indicated nitrate accumulation in soil,ground water and vegetables of these cancer villages adjacent to Shaying River were significantly higher than the average level of the study area. Nitrate accumulation in vegetable field of cancer villages was the most severe among all kinds of the crop fields,with soil nitrate-N of 276.44 mg·kg^-1in crop growth period and 68.26 mg·kg^-1in post-harvest period. The average nitrate-N in ground water reached 38.32 mg·L^-1,around 3 times higher than the standard,and the average nitrate-N in leaf vegetables was 3269.04 mg·kg^-1,2 times higher than the permissible content. Higher nitrate-N concentration in ground water and vegetable indicated that the local residents of cancer village were suffering high nitrate-N health risks from drinking water and vegetables.