Drinking Water Disinfection Byproducts (DBPs) and Human Health Effects: Multidisciplinary Challenges and Opportunities

TLDR

Disinfection of drinking water prevents disease but generates over 600 disinfection byproducts, of which only a few classes such as trihalomethanes are regulated, yet epidemiological evidence links chlorinated water to bladder cancer and the specific toxic DBPs remain unidentified. Utilities are shifting from chlorination of pristine supplies to using new disinfectant combinations for waters impacted by wastewater effluents and algal blooms. The article aims to discuss new interdisciplinary approaches to identify the DBP classes responsible for disinfected water toxicity. It concludes that DBP exposure should be measured using additional DBP classes beyond trihalomethanes.

Abstract

While drinking water disinfection has effectively prevented waterborne diseases, an unintended consequence is the generation of disinfection byproducts (DBPs). Epidemiological studies have consistently observed an association between consumption of chlorinated drinking water with an increased risk of bladder cancer. Out of the >600 DBPs identified, regulations focus on a few classes, such as trihalomethanes (THMs), whose concentrations were hypothesized to correlate with the DBPs driving the toxicity of disinfected waters. However, the DBPs responsible for the bladder cancer association remain unclear. Utilities are switching away from a reliance on chlorination of pristine drinking water supplies to the application of new disinfectant combinations to waters impaired by wastewater effluents and algal blooms. In light of these changes in disinfection practice, this article discusses new approaches being taken by analytical chemists, engineers, toxicologists and epidemiologists to characterize the DBP classes driving disinfected water toxicity, and suggests that DBP exposure should be measured using other DBP classes in addition to THMs.