Contamination status of highly toxic halonitromethanes, haloacetonitriles, and haloacetamides in drinking water

Nitrogen-containing disinfection by-products (N-DBPs) have attracted increasing attention due to their significantly higher toxicity compared with regulated disinfection by-products in drinking water. Environmental pollution and the improvement of drinking water disinfection technology may increase the occurrence of N-DBPs in drinking water. This paper reviews the three typical halogenated N-DBPs concentrations of halonitromethanes (HNMs), haloacetonitriles (HANs), and haloacetamides (HAMs) in drinking water in some cities around the world. Globally, the concentrations of HNMs, HANs, and HAMs ranged from 0.1~2.9 μg/L, 0.6~4.3 μg/L, and 0.2~3.5 μg/L, respectively, and the concentrations showed the order of HANs (2.6 μg/L)>HAMs (1.5 μg/L)>HNMs (1.1 μg/L). In China, the average concentration of HANs was 3.6 μg/L, which was significantly higher than that in the United States (2.1 μg/L) and Europe (1.6 μg/L), which deserves further attention. Water disinfection and treatment processes have complex and variable effects on the concentrations of N-DBPs. Terminal control strategies can effectively reduce the concentrations of N-DBPs in the human body through drinking water, thereby reducing the threat of N-DBPs to human health.