Health risk assessment of drinking water in Ningbo City / 预防医学

ABSTRACT

Objective@#To evaluate the health risk of drinking water in Ningbo City, Zhejiang Province from 2021 to 2022, so as to provide insights into ensuring the safety of drinking water.@*Methods@#The monitoring data of drinking water from 2021 to 2022 in Ningbo City were collected from the Chinese Disease Prevention and Control Information System. The routine indicators and disinfectant indicators (radioactivity indicators were excluded) of drinking water were evaluated according to the reference limits issued by Standards for Drinking Water Quality (GB 5749-2006), and the qualification rates were calculated. The indicators with detection rate higher than 50% were selected, and assessed the carcinogenic and non-carcinogenic risks via drinking water using the risk assessment model recommended by the United States Environmental Protection Agency.@*Results@#A total of 1 678 samples were monitored in Ningbo City from 2021 to 2022. Sodium hypochlorite was the main disinfectant among 1 558 samples from centralized water supply (1 079 samples, 64.30%), and none of the 120 samples from decentralized water supply underwent disinfection treatment. The qualification rate of 88.38%, and the pollutants with a detection rate higher than 50% were nitrate, fluoride, trichloromethane and aluminum. The median carcinogenic risk value of trichloromethane was 2.964×10-6 (interquartile range, 3.909×10-6), and the median hazard quotient values of nitrate, fluoride, trichloromethane and aluminum were 1.631×10-2 (interquartile range, 1.361×10-2), 3.955×10-2 (3.164×10-2), 2.231×10-2 (2.942×10-2) and 2.136×10-4 (6.573×10-4), respectively.@*Conclusion@#The carcinogenic and non-carcinogenic risks through drinking water for 17 pollutants in drinking water of Ningbo City from 2021 to 2022 were at low levels.