Identifying Genotoxicity Forcing Agents from Individual Aliphatic and Aromatic Disinfection Byproducts in Drinking Water and Wastewater Effluents

Abstract

Previous studies mainly investigated the cytotoxicity forcing agents from individual aliphatic and aromatic disinfection byproducts (DBPs), but the genotoxicity forcing agents among them in drinking water and wastewater effluents remain largely veiled. In this study, the relative concentration-genotoxicity contributions of five groups of aliphatic DBPs (trihalomethanes, haloacetic acids (HAAs), haloacetonitriles, haloacetamides, and halonitromethanes) and seven groups of aromatic DBPs (halophenols, halohydroxybenzoic acids, halohydroxybenzaldehydes, halonitrophenols, halohydroxybenzonitriles, halophenylacetamides, and haloanilines) were analyzed according to the acquired concentration and genotoxicity data alongside the total ion current-toxicity potency (TIC-Tox) method. Notably, the comparative genotoxicity of aromatic DBPs was quantitatively evaluated for the first time, and the corresponding quantitative structure–activity relationship model with satisfactory goodness-of-fit, robustness, and prediction performance was developed. Among these aromatic DBPs, halophenols were identified as possessing the highest genotoxicity. In both drinking water and wastewater effluents, aliphatic DBPs exhibited overwhelmingly higher relative concentration-genotoxicity contributions compared to aromatic DBPs. The genotoxicity forcing agents among aliphatic and aromatic DBPs in drinking water were identified as HAAs and haloanilines, respectively, which differed from the cytotoxicity forcing agents. In wastewater effluents, the genotoxicity forcing agents were identified as HAAs and halophenols, respectively. This work fills a critical knowledge gap regarding the genotoxicity forcing agents from individual DBPs in drinking water and wastewater effluents.