Spatial, temporal variability and carcinogenic health risk assessment of nitrosamines in a drinking water system in China
Spatial, temporal variability and carcinogenic health risk assessment of nitrosamines in a drinking water system in China
复制标题
中国饮用水系统中亚硝胺的时空变化及致癌健康风险评估
DOI：
10.1016/j.scitotenv.2020.139695
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发表时间：
2020
影响因子：
9.8
通讯作者：
Zeng Qiang
中科院分区：
文献类型：
--
作者：
Luo Qiong;Bei Er;Liu Chong;Deng Yan-Ling;Miao Yu;Qiu Yu;Lu Wen-Qing;Chen Chao;Zeng Qiang
亚硝胺作为一类饮用水中常见的含氮消毒副产物，因其潜在的高健康风险而受到越来越多的关注。饮用水系统中亚硝胺的存在变化及其致癌健康风险研究较少。我们的研究旨在调查饮用水系统中亚硝胺的时空变异性，并进行致癌健康风险评估。在一年中，每月采集一次我国中部地区二氧化氯-氯联用饮用水系统的进水、处理水和自来水3种水样，测定了9种亚硝胺。结果表明，N-亚硝基二甲胺（NDMA）是最常见的化合物，其平均浓度为2.5 ~ 67.4 ng/L，其次是N-亚硝基二乙胺（NDEA）和N-亚硝基哌啶（NPIP）。自来水中亚硝胺的含量逐月变化，季节性差异显著（p<0.05）.从进水到处理水再到自来水，NDMA、NDEA和NPIP的平均浓度呈下降趋势，但在配水系统内没有观察到显著的空间变异性（p> 0.05）。三种主要亚硝胺的平均和第95百分位数的终生癌症风险分别为4.83 × 10− 5和4.48 × 10−4，超过了美国环保局提出的可忽略风险水平（10−6）。饮用水中的亚硝胺暴露对儿童的癌症风险高于成人，0.75至1岁的儿童患癌症的风险最高。这些结果表明，亚硝胺发生在自来水中的时间变化，但没有空间。饮用水中的亚硝胺可能对人体健康，特别是儿童的健康构成致癌风险。
Nitrosamines, as a class of emerging frequently detected nitrogenous disinfection byproducts (N-DBPs) in drinking water, have gained increasing attention due to their potentially high health risk. Few studies focus on the occurrence variation and carcinogenic health risk of nitrosamines in drinking water systems. Our study aimed to investigate the spatial and temporal variability of nitrosamines in a drinking water system and to conduct a carcinogenic health risk assessment. Three types of water samples, including influent water, treated water and tap water, were collected monthly during an entire year in a drinking water system utilizing a combination of chlorine dioxide and chlorine in central China, and 9 nitrosamines were measured. The nitrosamine formation potentials (FPs) in influent water were also determined.N-nitrosodimethylamine (NDMA) was the most prevalent compound and was dominant in the water samples with average concentrations ranging from 2.5 to 67.4 ng/L, followed by N-nitrosodiethylamine (NDEA) and N-nitrosopiperidine (NPIP). Nitrosamine occurrence varied monthly, and significant seasonal differences were observed in tap water (p< .05). There were decreasing mean NDMA, NDEA and NPIP concentrations from influent water to treated water to tap water, but no significant spatial variability was observed within the water distribution system (p> .05). The average and 95th percentile total lifetime cancer risks for the three main nitrosamines were 4.83 × 10−5and 4.48 × 10−4, respectively, exceeding the negligible risk level (10−6) proposed by the USEPA. Exposure to nitrosamines in drinking water posed a higher cancer risk for children than for adults, and children aged 0.75 to 1 years suffered the highest cancer risk. These results suggest that nitrosamine occurrence in tap water varied temporally but not spatially. Exposure to drinking water nitrosamines may pose a carcinogenic risk to human health, especially to children.