Pollution levels and health risk assessment of nitrosamines in pipeline direct drinking water from primary and secondary schools in Shanghai
- VernacularTitle:上海市中小学校管道直饮水中亚硝胺类化合物污染水平及健康风险评估
- Author:
Ting WANG
1
;
Chaoye SHEN
2
;
Zhe CHEN
1
;
Jian CHEN
1
;
Yi SU
1
Author Information
- Publication Type:Investigation
- Keywords: nitrosamine; direct drinking water; primary and secondary school; distribution; health risk
- From: Journal of Environmental and Occupational Medicine 2026;43(5):637-642
- CountryChina
- Language:Chinese
- Abstract: Background Nitrosamines (NAms), emerging as disinfection by-products in drinking water, are highly carcinogenic. Given the significant NAms contamination reported in various regions of China, evaluating the contamination levels and health risks of NAms in terminal direct drinking water is of great urgency. Objective To investigate the concentration levels of NAms in piped direct drinking water at primary and secondary schools in Shanghai, and to assess the potential health risks posed to different age groups through this exposure pathway. Methods A total of 198 water samples were collected from 66 primary and secondary schools across five districts in Shanghai from May to June 2023. The mass concentrations of eight major NAms were quantified using solid-phase extraction coupled with gas chromatography-mass spectrometry (GC-MS). A carcinogenic health risk model was employed to evaluate the lifetime cancer risks associated with NAms exposure via direct drinking water for various age groups. Results Among the 198 samples, NAms were detected in 196 samples, with concentrationsranging from below the limit of detection (LOD) to 106.06 ng·L−1. The average concentration of total NAms was 21.30 ng·L−1, with N-nitrosodimethylamine (NDMA) exhibiting the highest detection rate at 98.5%. Significant differences in NAms concentrations were observed among water treatment systems utilizing ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) as core processes (P<0.05). The lifetime cancer risks for different age groups ranged from 1.38×10−6 to 1.11×10−5, with NDMA contributing the most to the overall risk (82.1%). The carcinogenic risk for adults (1.08×10−5) was higher than that for children and adolescents (1.38×10−6 to 2.61×10−6). Among children and adolescents under 18 years of age, the risk decreased as age increased. Conclusion Trace levels of NAms, primarily NDMA, are detected in the piped direct drinking water at primary and secondary schools in Shanghai, with concentrations vary significantly depending on the water treatment process. The carcinogenic risks of NAms exposure via direct drinking water for all age groups are below the acceptable level (1×10−4) recommended by the U.S. Environmental Protection Agency (EPA).
