Research Issues Underlying the Four-Lab Study: Integrated Disinfection By-Products Mixtures Research

Abstract

Chemical disinfection of drinking water is a major public health triumph of the 20th century, resulting in significant decreases in morbidity and mortality from waterborne diseases. Disinfection by-products (DBP) are chemicals formed by the reaction of oxidizing disinfectants with inorganic and organic materials in the source water. To address potential health concerns that cannot be answered directly by toxicological research on individual DBPs or defined DBP mixtures, scientists residing within the various organizations of the U.S. Environmental Protection Agency's Office of Research and Development (the National Health and Environmental Effects Research Laboratory, the National Risk Management Research Laboratory, the National Exposure Research Laboratory, and the National Center for Environmental Assessment) engaged in joint investigation of environmentally realistic complex mixtures of DBP. Research on complex mixtures of DBP is motivated by three factors: (a) DBP exposure is ubiquitous to all segments of the population; (b) some positive epidemiologic studies are suggestive of potential developmental, reproductive, or carcinogenic health effects in humans exposed to DBP; and (c) significant amounts of the material that makes up the total organic halide portion of the DBP have not been identified. The goal of the Integrated Disinfection Byproducts Mixtures Research Project (the 4Lab Study) is provision of sound, defensible, experimental data on environmentally relevant mixtures of DBP and an improved estimation of the potential health risks associated with exposure to the mixtures of DBP formed during disinfection of drinking water. A phased research plan was developed and implemented. The present series of articles provides the results from the first series of experiments.

The authors are grateful to the cross-disciplinary team of scientists within ORD, and to our extramural collaborators, who worked cooperatively and collaboratively to conduct the multiphased experiments described in this and the following seven articles. The authors are grateful to A. McDonald for aid in preparation of this article. The authors thank NHEERL, NCEA, NERL, NRMRL, and ORD management for their support of this cross-laboratory research effort.

This article has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the agency, nor does mention of trade names constitute endorsement or recommendation for use.