| 清江流域亚硝胺及其前体物质的分布特征及风险评价 |
| 摘要点击 881 全文点击 235 投稿时间：2023-06-27 修订日期：2023-09-28 |
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| 中文关键词 清江流域 亚硝胺 生成势（FP） 致癌风险 生态风险 |
| 英文关键词 Qingjiang River Basin N-nitrosamines formation potential（FP） carcinogenic risks ecological risks |
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| 中文摘要 |
| 亚硝胺是一类具有高致癌性和致突变性的含氮有机污染物. 支流水系作为我国中小城镇的主要饮用水源,其亚硝胺的污染情况尚不明确,关于支流河水中亚硝胺及其前体物质浓度的研究仍十分缺乏. 以水体中常见8种亚硝胺为研究对象,检测了长江一级支流清江河水及氯胺化处理后水样中亚硝胺浓度组成特征,并针对重要的污水排放源进行重点监测,分析亚硝胺及其前体物质的环境影响因素,评估其健康和生态风险. 结果表明,清江河水共检出6种亚硝胺,其中主要亚硝胺为NDMA[（10 ±15）ng·L-1]、NDEA[（9.3 ±9.3）ng·L-1]和NDBA[（14 ±7.8）ng·L-1],氯胺化反应后的水样中有7种亚硝胺检出,主要为NDMA-FP[（46 ±21）ng·L-1]、NDEA-FP[（26 ±8.3）ng·L-1]和NDBA-FP[（22 ±13）ng·L-1]；河水中亚硝胺的浓度分布整体呈现为中游高于上游和下游,在有污水排放与支流汇入点的亚硝胺浓度明显高于其他点位；对污水直接排放点的监测发现,携带有亚硝胺及其前体物质的污水输入是河水中亚硝胺的主要来源；此外,3种主控污染物NDMA、NDBA和NDEA的浓度存在一定相关性,主要原因是其存在相似的污水来源；饮用水源地亚硝胺浓度对当地居民存在潜在致癌风险（2.4×10-5）；此外,由于清江具有较高的亚硝胺生成潜能,其饮用水致癌风险可能会更高；生态风险评价表明,亚硝胺对于清江流域的生态风险商值低于0.002,生态风险可忽略不计. |
| 英文摘要 |
| N-nitrosamines are a type of nitrogen-containing organic pollutant with high carcinogenicity and mutagenicity. In the main drinking water sources of small and medium-sized towns in China, the contamination levels of N-nitrosamines remain unclear. In addition, there is still lack of research on the concentration of N-nitrosamines and their precursors in tributary rivers. In this study, eight N-nitrosamines and their formation potentials （FPs） were investigated in the Qingjiang River, which is a primary tributary of the Yangtze River. The sewage discharge sites were also monitored, and the environmental influencing factors, carcinogenic and ecological risks caused by N-nitrosamines, and their precursors were evaluated. The results showed that six N-nitrosamines were detected in water samples of the Qingjiang River, among which NDMA [（10 ±15） ng·L-1], NDEA [（9.3 ±9.3） ng·L-1], and NDBA [（14 ±7.8） ng·L-1] were the dominant N-nitrosamines, whereas seven N-nitrosamines were detected in chloraminated water samples, among which NDMA-FP [（46 ±21） ng·L-1], NDEA-FP [（26 ±8.3） ng·L-1], and NDBA-FP [（22 ±13） ng·L-1] were the dominant N-nitrosamine FPs. The concentrations of N-nitrosamines in the middle reaches of the Qingjiang River were higher than those in the upper and lower reaches. Furthermore, the concentrations of N-nitrosamines in the sample sites of sewage discharge and tributaries were significantly higher than those in other sampling sites. The monitoring results at the direct sewage discharge points indicated that the main source of N-nitrosamines in river water was the sewage carrying N-nitrosamines and their precursors. In addition, the concentrations of the three dominant N-nitrosamines including NDMA, NDBA, and NDEA were positively correlated with each other, mainly because of their similar sewage sources. The average carcinogenic risk to residents due to N-nitrosamine in drinking water sources was 2.4×10-5, indicating a potential carcinogenic risk. Moreover, due to the high concentrations of N-nitrosamine formation potentials in the Qingjiang River, the carcinogenic risk of drinking water may be even higher. The ecological risk assessment showed that the ecological risk quotient values of N-nitrosamines in the Qingjiang River watershed were lower than 0.002, which was negligible. |
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