Analytical discovery of water disinfection byproducts of toxicological relevance: highlighting halobenzoquinones

Analytical advancement enables discoveries in water research, and challenges in the identification and determination of a wide range of trace level toxic compounds in water drives the development of new analytical platforms and tools. The identification of toxic disinfection byproducts (DBPs) in disinfected drinking water is an excellent example. Water disinfection is necessary to protect the public from waterborne disease. However, an unintentional consequence is the formation of DBPs resulting from reactions of disinfectants with natural organic matter in source water. To date, regulated DBPs do not account for the increased bladder cancer risk estimated in epidemiological studies. The majority of halogenated DBPs remain unidentified and the discovery of unknown DBPs of toxicological relevance continues to be a major focus of current water research. This review will highlight halobenzoquinones as a class of DBPs that serves as an example of analytical development and toxicological studies. We will feature recent trends and gaps in analytical technologies for identification of unknown DBPs and bioassays for evaluation of the toxicological effects of specific DBPs and their mixtures.