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

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.

Using indicators to assess microbial treatment and disinfection efficacy

“…Several studies have shown disadvantages of chlorination such as the production of disinfection byproducts (DBPS), which is the product of disinfectants reaction with natural organic matter in water. As a result, it is crucial to strike a balance between the chronic risk posed by lifetime exposure to DBPs and its advantages (Li and Mitch, 2018;Costet et al, 2011). Nevertheless, almost all surface water treatment plants in the United States of America (USA) still use chlorine-based disinfectants as part of their treatment process and almost 98% of Western Europe's water is also chlorinated (Ngwenya et al, 2013).…”

A multiple‐site field study of stabilized hydrogen peroxide for drinking water disinfection

“…Alternative disinfection technologies using nonhalogenated disinfectants (e.g., ultraviolet and ozone) provide adequate primary disinfection and can lead to reduced levels of regulated DBPs in drinking water (Krasner, ; Li & Mitch, ). In the United States, 7% of utilities have switched from chlorine disinfection to other types of primary disinfection, such as chlorine dioxide, ozone, or ultraviolet treatment, while 20% of utilities use chloramine for secondary disinfection (AWWA, ).…”

Vulnerability Assessment to Trihalomethane Exposure in Water Distribution Systems

“…Over the last 30 years, numerous DBPs have been studied and classified, including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloketones (HKs). Even if it is unclear which specific DBPs are responsible for the adverse health effects [20,21], only two classes of DBPs-THMs and HAA-are regulated. The four THMs species (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) are produced from sodium hypochlorite reacting with the NOM.…”