硝酸盐,作为一种关键的营养素,一直是全球控制水富营养化的目标。然而,有大量证据表明硝酸盐对水生生物具有内分泌干扰潜力。在这项研究中,比较了各种不利影响对硝酸盐氮(硝酸盐-N)的敏感性,并得出了基于内分泌干扰作用的毒性阈值。研究了滦河流域硝酸盐氮浓度的时空变化,并采用综合方法对相关的水生生态风险进行了评价。结果表明,生殖和发育是硝酸盐最敏感的终点,与行为相比,它们的分布表现出显著差异。基于内分泌干扰作用的推导阈值为0.65mgL-1,为水生生态系统提供了足够的保护。在滦河流域,冬季的平均硝酸盐氮浓度(4.4mgL-1)显着高于春季(0.7mgL-1)和夏季(1.2mgL-1)。支流输入对主流中硝态氮的空间特征有重要影响,主要是由于农业和人口相关的污染。冬季的风险商(RQ),夏天,和弹簧分别被评估为6.7、1.8和1.1,暴露浓度超过阈值的频率为100%,64.3%,和42.5%,分别。在生态系统层面,在Lu河流域和全国范围内,硝酸盐对冬季和夏季的水生生物构成了中等风险。我们建议硝酸盐污染控制不仅应关注水体富营养化,还应考虑对水生动物的内分泌干扰作用。
Nitrate, as a crucial nutrient, is consistently targeted for controlling water eutrophication globally. However, there is considerable evidence suggesting that nitrate has endocrine-disrupting potential on aquatic organisms. In this study, the sensitivity of various adverse effects to nitrate nitrogen (nitrate-N) was compared, and a toxicity threshold based on endocrine-disrupting effects was derived. The spatiotemporal variations of nitrate-N concentrations in the Luan River basin were investigated, and the associated aquatic ecological risks were evaluated using a comprehensive approach. The results showed that reproduction and development were the most sensitive endpoints to nitrate, and their distribution exhibited significant differences compared to behavior. The derived threshold based on endocrine-disrupting effects was 0.65 mgL-1, providing adequate protection for the aquatic ecosystem. In the Luan River basin, the mean nitrate-N concentrations during winter (4.4 mgL-1) were significantly higher than those observed in spring (0.7 mgL-1) and summer (1.2 mgL-1). Tributary inputs had an important influence on the spatial characteristics of nitrate-N in the mainstream, primarily due to agricultural and population-related contamination. The risk quotients (RQ) during winter, summer, and spring were evaluated as 6.7, 1.8, and 1.1, respectively, and the frequency of exposure concentrations exceeding the threshold was 100 %, 64.3 %, and 42.5 %, respectively. At the ecosystem level, nitrate posed intermediate risks to aquatic organisms during winter and summer in the Luan River basin and at the national scale in China. We suggest that nitrate pollution control should not solely focus on water eutrophication but also consider the endocrine disruptive effect on aquatic animals.