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U.S. Department of Energy
Office of Scientific and Technical Information

Assessing mixtures risks for cleanup and stewardship.

Conference ·
OSTI ID:799827
The U.S. Department of Energy (DOE) is responsible for addressing contamination from past research, production, and disposal activities at over 100 sites and facilities across the country. Use of emerging science to assess risks for these facilities is the key to defining appropriate solutions. Safely managing contamination is a priority to protect workers in the near term, and sustained protection is a priority for local communities over the long term. The Department conducts its environmental management program with input from a number of groups who have expressed concern about the safety of DOE sites over time and the possible conversion of some lands to other uses. In general, past facility activities and disposal operations have contaminated about 10% of the total collective area of DOE sites while surrounding lands have served as buffer zones. Portions of several sites have been released for other uses, such as wildlife preserves. Soil, surface water, and groundwater have been contaminated in most instances, and on-site waste disposal is targeted for many sites. Wastes and contamination that will remain in the environment are at the heart of ongoing future use and long-term management deliberations. For this reason, oversight groups and local citizens are scrutinizing the risk assessments being conducted to support decisions on final cleanup and long-term stewardship. Contaminants exist throughout the world not as individual chemicals but as combinations. The standard risk assessment process broadly applied to support cleanup decisions for contaminated sites is based on single-chemical analyses that do not consider joint toxicity. That is, possible nonadditive effects (commonly termed synergistic or antagonistic) of multiple exposures to multiple chemicals are not generally addressed. The U.S. Environmental Protection Agency (EPA) has been developing a process to assess risks of multiple chemicals (EPA 1990, 2000), but it is not yet being applied to address complex contaminated sites. To ensure continued health protection at DOE sites, various parties have asked that the risk assessments being conducted consider multiple chemicals, media, exposures, and receptors--including unique subgroups--over large spaces and extended time frames. Some have explicitly requested that potential synergism be evaluated, as well as health endpoints beyond the critical effect. In addition to the focus on long-term protection, recent catastrophic events that could cause widespread contaminant releases (fires and earthquakes) have heightened concerns about multiple-chemical, multiple-route exposures and cumulative effects.
Research Organization:
Argonne National Lab., IL (US)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
W-31109-ENG-38
OSTI ID:
799827
Report Number(s):
ANL/EA/CP-107011
Country of Publication:
United States
Language:
English