2014—2019年大连市农村饮用水硝酸盐含量监测及健康风险评估

Nitrate monitoring and health risk assessment of drinking water in rural areas of Dalian from 2014 to 2019

目的 为掌握大连农村生活饮用水硝酸盐含量动态变化及其特征,并评价硝酸盐对人体的健康风险。方法 2014-2019 年采集大连农村生活饮用水水样 2 370 份,按 GB/T5750-2006《生活饮用水标准检验方法》检测硝酸盐指标,采用美国环保局推荐的健康风险模型评估硝酸盐对人体健康风险。采用描述性流行病学方法进行统计分析,对数据进行χ^(2)检验及 Kruskal~Wallis H 检验,以 P<0.05 为差异有统计学意义。结果 硝酸盐合格率为 87.72%,浓度范围 0.004~120.930 mg/L,硝酸盐含量及合格率年间及地区间差异有统计学意义。幼儿、儿童、青少年、成年女性、成年男性硝酸盐暴露所致总健康风险中位数分别为68.69×10^(-2)/a、20.17×10^(-2)/a、13.85×10^(-2)/a、13.33×10^(-2)/a、14.10×10^(-2)/a;分别有 11.14%、3.42%、0.63%、0.51%和 0.38%的监测点饮用水对幼儿、儿童、成年男性、青少年及成年女性的总健康风险超过 1。结论 2014—2019 年大连农村饮用水硝酸盐超标情况有所改善;未成年人较成年人更易受硝酸盐污染的危害;大部分农村饮用水中硝酸盐健康风险可接受,未来应重点关注健康风险指数大于1的监测点。

Objective To investigate that content and change trend of nitrate index of drinking water in Dalian,the health risk of nitrate was analyzed on the basis of monitoring results. Methods From 2014 to 2019,2 730 rural drinking water samples were collected. According to the Standard Examination Method for Drinking Water (GB/T 5750- 2006), nitrate index was detected. The health risk assessment in rural drinking water was evaluated by the model recommended by the United States Environmental Protection Agency. Descriptive statistics were performed. Chi-square tests and Kruskal-H Wallis tests were used, and P<0.05 was considered as statistically significant. Results The qualified rate of nitrate content was 87.72% , and the concentration range of nitrate was 0.004~120.93 mg/L. There were statistically significant differences in nitrate content and the qualified rate between years and regions. The median of total health risk caused by nitrate exposure in infants, children, adolescents,adult women and adult men was 68.69×10^(-2)/a,20.17×10^(-2)/a,13.85×10^(-2)/a,13.33×10^(-2)/a,14.10×10^(-2)/a,respectively. Notably,11.14%,3.42%,0.63%,0.51% and 0.38% of the monitoring points had the health risk of nitrate in drinking water more than 1 for infants, children, adult men, adolescents and adult women, respectively. Conclusions From 2014 to 2019, the situation of excessive nitrate in rural drinking water has improved in Dalian. The minors are more vulnerable to nitrate pollution than adults. The total health risk of nitrate in most of the rural drinking waters is acceptable. We should focus on monitoring points with health risk more than 1 in the future.