Evaluation of Disinfection Byproducts for Their Ability to Affect Mitochondrial Function.

In the race to deliver clean water to communities through potable water reuse, disinfection and water quality assessment are and will continue to be fundamental factors. There are over 700 disinfection byproducts (DBPs) in water; evaluating each compound is practically impossible and very time consuming. A bioanalytical approach could be an answer to this challenge. In this work, the response of four major classes of DBPs toward mitochondrial membrane potential (Delta Psi m) and cytoplasmic adenosine triphosphate (C-ATP) was investigated with human carcinoma (HepG2) cells. Within 90 min of cell exposure, only the haloacetic acid (HAA) mixture caused a cytotoxic response as measured by C-ATP. All four groups (haloacetonitriles (HANs), trihalomethanes (THMs), nitrosamines (NOAs), and HAAs) responded well to Delta Psi m, R-2 > 0.70. Based on the half-maximum concentration that evoked a 50% response in Delta Psi m, the response gradient was HANs >> HAAs similar to THM > NOAs. The inhibition of the Delta Psi m by HANs is driven by dibromoacetonitrile (DBAN), while dichloroacetonitrile (DCAN) did not cause a significant change in the Delta Psi m at less than 2000 mu M. A mixture of HANs exhibited an antagonistic behavior on the Delta Psi m compared to individual compounds. If water samples are concentrated to increase HAN concentrations, especially DBAN, then Delta Psi m could be used as a biomonitoring tool for DBP toxicity. (C) 2022 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.