State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China; School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China.
College of Environmental Science and Engineering, Guilin University of Technology, Guilin, 541004, China.
Environ Res. 2021 Apr;195:110673. doi: 10.1016/j.envres.2020.110673. Epub 2021 Jan 27.
The presence of some types of N-nitrosamines in water bodies is of great concern worldwide due to their carcinogenic risks and harmful mutagenic effects on human health. In the present study, eight N-nitrosamines and their formation potentials (FPs) were primarily investigated in Yangtze River surface water to evaluate their spatial distribution, mass loads, and ecological risks. The results showed that of the eight N-nitrosamines investigated, NDMA (<1.5-17 ng/L), NDEA (<1.4-9.5 ng/L), NDPA (1.0 ng/L), NMOR (<1.0-1.3 ng/L), NPIP (<2.1-3.7 ng/L), and NDBA (<3.6-30 ng/L) were detected. The FPs of NDMA (<27-130 ng/L), NDEA (<0.9-2.3 ng/L), NDPA (<1.2-1.9 ng/L), NPYR (<1.4-2.9 ng/L), NMOR (<1.0 ng/L), and NDBA (<1.1-14 ng/L) were significantly identified. NDBA was predominantly observed in surface water, while NDMA was noticeably detected in chloraminated water samples. It was estimated that approximately 5.4 t/y of N-nitrosamines were carried by the Yangtze River to the East China Sea, whereas the input flux of N-nitrosamine precursors was estimated to be approximately 69.5 t/y. Spatial variations were observed due to the input of N-nitrosamines from the upstream dams and lakes. The origin of N-nitrosamine precursors was not associated with the presence of sediment in river water. NDEA could be introduced into river water by the discharge of wastewater. NDBA and its precursors could originate from industrial and aquaculture activities. NDMA and its precursors could result from both of the aforementioned sources. Moreover, the wastewater discharge from small cities, pH value, wastewater treatment ratio, and dilution could be the key factors that influence the occurrence of N-nitrosamines along the Yangtze River. More attention should be paid to the cancer risks posed by N-nitrosamines. The ecological risks posed by N-nitrosamines in the Yangtze River can be ignored.
水体中某些类型的 N-亚硝胺因其致癌风险和对人类健康的有害诱变作用而引起了全球关注。本研究主要研究了长江表层水中的 8 种 N-亚硝胺及其形成潜力 (FP)，以评估其空间分布、质量负荷和生态风险。结果表明，在所研究的 8 种 N-亚硝胺中，NDMA(<1.5-17ng/L)、NDEA(<1.4-9.5ng/L)、NDPA(1.0ng/L)、NMOR(<1.0-1.3ng/L)、NPIP(<2.1-3.7ng/L)和 NDBA(<3.6-30ng/L)被检测到。NDMA(<27-130ng/L)、NDEA(<0.9-2.3ng/L)、NDPA(<1.2-1.9ng/L)、NPYR(<1.4-2.9ng/L)、NMOR(<1.0ng/L)和 NDBA(<1.1-14ng/L)的 FP 显著确定。NDBA 主要存在于地表水中，而 NDMA 则明显存在于氯胺化水样中。据估计，长江每年携带约 5.4 吨 N-亚硝胺入海，而 N-亚硝胺前体的输入通量估计约为 69.5 吨/年。由于上游大坝和湖泊输入 N-亚硝胺，观察到空间变化。N-亚硝胺前体的来源与河水中沉积物的存在无关。NDEA 可能通过废水排放进入河水。NDBA 及其前体可能来自工业和水产养殖活动。NDMA 及其前体可能来自上述两种来源。此外，来自小城市的废水排放、pH 值、废水处理率和稀释度可能是影响长江沿线 N-亚硝胺发生的关键因素。应更加关注 N-亚硝胺带来的致癌风险。长江 N-亚硝胺的生态风险可以忽略不计。
