Environmental Risk Assessment

This paper presents a current overview of the basic elements of environmental risk assessment within the basic four-step process of hazard identification, exposure assessment, toxicity assessment, and risk characterization. These general steps have been applied to assess both human and ecological risks from environmental exposures. Approaches used to identify hazards and exposures are being refined, including the use of optimized field sampling and more representative, rather than conservative, upper-bound estimates. In addition, toxicity data are being reviewed more rigorously as U.S. and European harmonization initiatives gain strength, and the classification of chemicals has become more qualitative to more flexibly accommodate new dose-response information as it is developed. Finally, more emphasis is being placed on noncancer end points, and human and ecological risks are being weighed against each other more explicitly at the risk characterization phase. Recent advances in risk-based decision making reflect the increased transparency of the overall process, with more explicit incorporation of multiple trade-offs. The end reklt is a more comprehensive life-cycle evaluation of the risks associated with environmental exposures at contaminated sites. Work supported by the U.S. Department of Energy, Office of Environmental Management, under contract W-3 1109-Eng-38. The submitted manuscript has been created ’ by the University of Chicago as Operator of 1 Argonne National Laboratory (“Argonne”) under Contract No. W-31-109-ENG-38 with the U.S. Department of Energy. The US. Government retains for itself, and others acting on its behalf, a paid-up, nonexclusive, irr&ocable worldwide license in said article ~ to reproduce, prepare derivative works, distribute copies to the public, and perform pub1 licly and display publicly, by or on behalf of the Government.