松嫩平原地下水氮污染健康风险评估

Health risk assessment of groundwater nitrogen pollution in Songnen Plain

为探明松嫩平原地下水氮污染现状及其对人类健康的影响,利用浅层地下水采样测试数据,运用地统计学分析及三角随机模型开展了儿童和成人群体摄入氮污染风险评估及其不确定性研究.结果表明:研究区氮污染物主要存在形式为硝态氮,样品超标率为44.35%,最大值达到566.2mg/L,硝态氮浓度大于20mg/L的区域约占区内总面积的60%,主要分布在东中部高平原地区,西部山前倾斜平原污染较轻;以Isight5.9-2为平台,基于三角模糊法耦合随机模型,考虑人类活动及农业发展的影响,将研究区划分为不同单元,非致癌风险排序为:评价单元Ⅲ>评价单元Ⅱ>评价单元Ⅰ,且单元Ⅲ污染物主要来源于农业活动,单元Ⅲ、Ⅱ区域风险远高于安全阈值1,会对儿童和成人群体健康造成潜在危害,对儿童威胁更大;污染物浓度和参数的不确定性对风险值影响的波动范围较大,三角随机模型对数据变化更为敏感,可降低三角模糊法的不确定性,单元Ⅰ儿童风险区间值横跨安全阈值1,可能会误导污染防控决策;硝态氮浓度对风险贡献率均在90%以上,明确对硝态氮浓度参数随机抽样的必要性,提高评价结果的可靠性.

To explore the Songnen Plain of nitrogen pollution and its effect on human health,this study employed shallow groundwater sampling test data,geostatistical analysis and conducted the triangular random model to assess the risk of nitrogen exposure in children and adults,and performed the uncertainty analysis.The results showed that:The main nitrogen pollutants was nitrate nitrogen,and the sample exceeded the standard rate of 44.35%,and the maximum value reached 566.2mg/L,and the region with a concentration of nitrate nitrogen greater than 20mg/L accounted for about 60%of the total area in the region,mainly distributed in the high plain area of the eastern and central parts,and the western front slope plain was less polluted;Based on the triangular fuzzy coupled stochastic model on the Isight 5.9-2platform,considering the impact of human activities and agricultural development,the study area was divided into different units.The non-carcinogenic risk ranking was:evaluation unit III>evaluation unit II>evaluation unit I,and the contaminants in Unit III were mainly derived from agricultural activities,and the risks in Units III and II were much higher than the safety threshold value of 1,which may cause potential harm to children and adults,and threaten children more;The uncertainty of pollutant concentration and parameters had a large fluctuation range for the risk value,and the triangular random model was more sensitive to data changes,which can reduce the uncertainty of the triangular fuzzy method.The unit I risk interval value crossed the safety threshold 1,and it may mislead pollution prevention and control decisions;the contribution rate of nitrate nitrogen concentration to risk was above 90%,which clarified the necessity of random sampling to improve the reliability of the evaluation results.