Research progress on the toxicity mechanisms and health risks of <i>N</i>-nitrosamine disinfection by-products in drinking water

ABSTRACT The safety of drinking water is a global issue, with N-nitrosamines (NAs), a type of nitrogen-containing disinfection by-product (N-DBPs), frequently detected in mixtures worldwide. High concentrations of individual NAs have been shown to possess significant teratogenic, carcinogenic, and genotoxic properties. Nonetheless, the health implications of NAs at environmental concentrations found in drinking water are not well understood. This necessitates research into the potential health risks posed by NA exposure through drinking water. This review focuses on the formation and transformation of NA chlorination DBPs in drinking water, their cytotoxicity, genotoxicity, and carcinogenicity at environmental levels, and the mechanisms behind these toxic effects. The insights gained are intended to guide enhancements in chlorination disinfection processes to minimize DBP formation, ensuring the provision of safer and cleaner drinking water, and to offer scientific evidence on the health effects of low-dose mixed NAs in drinking water.