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The Power of Four (the 4-Lab Study): ORD’s Integrated Disinfection By-Products Mixtures Research Project
Citation:
SIMMONS, J. E., S. D. RICHARDSON, G. E. RICE, T. F. SPETH, R. J. MILTNER, E. S. HUNTER, M. G. NAROTSKY, K. M. SCHENCK, L. D. CLAXTON, R. A. PEGRAM, T. A. MCDONALD, D. S. BEST, S. H. WARREN, A. B. DEANGELO, W. O. WARD, J. G. PRESSMAN, AND L. K. TEUSCHLER. The Power of Four (the 4-Lab Study): ORD’s Integrated Disinfection By-Products Mixtures Research Project. Presented at Office of Solid Waste Science Seminar, Washington, DC, September 09 - 12, 2008.
Impact/Purpose:
The intended result of chemical disinfection of drinking water is reduction of microbial contamination; the unintended consequence is the formation of disinfection by-products (DBPs).
Description:
Chemical disinfection of water, a major public health triumph of the 20th century, has resulted in dramatic decreases in morbidity and mortality from water-borne disease. The intended result of chemical disinfection of drinking water is reduction of microbial contamination; the unintended consequence is the formation of disinfection by-products (DBPs). DBPs are present in water as highly complex mixtures. To date, more than 600 unique DBPs have been identified; despite this massive identification effort, a large portion of the total organic halide formed as a result of disinfection remains unknown. The goal of the Integrated Disinfection By-Products Mixtures Research Project (the 4-Lab Study) is development of sound, defensible, experimental data on environmentally relevant mixtures of DBPs and an improved estimation of the potential health risks associated with exposure to the mixtures of DBPs formed during disinfection of drinking water. This research effort was conceived, developed, and implemented by a cross-disciplinary team of scientists from four Laboratories/Centers of the Office of Research and Development of the U.S. EPA, in conjunction with an array of extramural partners. This presentation will summarize the scientific and regulatory issues underlying the need for research on DBP mixtures, and provide an overview of the multi-faceted, multi-disciplinary research efforts that comprise the 4-Lab Project. A phased research plan was developed and implemented. This presentation will provide the results from the first two phases of experimentation. These research efforts include development of a novel system for preparation of water concentrates from EPA-compliant disinfected water, quantitative as well as comprehensive qualitative chemical analysis, in vivo and in vitro toxicological assessment and new risk assessment methods for complex mixtures. The results from these phases led to refinements in the experimental design for the comprehensive in vivo reproductive/developmental multi-generational bioassay integrated with extensive chemical analysis and complementary in vitro investigations. New methods and techniques that will be useful for other programs have been developed, such as: methods for addressing statistical power and an advanced method for delivery of water to experimental animals that both reduces the volume of water needed and optimizes the conditions under which the water is held while being available to experimental animals. (This abstract does not reflect EPA policy.)