Abstract
BACKGROUND: Drinking water disinfection generates disinfection by-products (DBPs) with adverse health impacts. Despite regulatory measures to limit DBPs levels, uncertainties remain about cumulative risks from complex DBPs mixtures, especially for children and adolescents. This study used centralized water supply quality monitoring data from Ningbo to assess health risks of DBPs via drinking water ingestion for children and adolescents aged 6-17. METHODS: 886 water samples were collected from 69 waterworks in Ningbo. Six DBPs (trichloromethane, dibromochloromethane, bromodichloromethane, tribromomethane, dichloroacetic acid, and trichloroacetic acid) were analyzed in accordance with the Chinese Standard Examination Methods for Drinking Water (GB/T 5750-2023). The US EPA health risk assessment model was used to evaluate the carcinogenic and non-carcinogenic risks of DBPs via drinking water ingestion in children and adolescents aged 6-17 years (divided into four age groups). RESULTS: Across the four age groups, the median carcinogenic risks of the six DBPs were all below 10(-4), with the total median carcinogenic risk ranging from 27.487 × 10(-6) to 75.997 × 10(-6). Meanwhile, the median hazard quotients for the four age groups were all <1, and the total hazard quotient ranged from 4.181 × 10(-2) to 6.422 × 10(-2). CONCLUSION: The health risks associated with the six DBPs via drinking water ingestion is acceptable for children and adolescents aged 6-17 in Ningbo. To further reduce potential risks, measures such as upgrading water distribution systems, enhancing source water treatment, and optimizing disinfectant type selection are recommended.