Int. J. Environ. Res. Public Health 2012, 9, 1997-2019; doi:10.3390/ijerph9061997 OPEN ACCESS International Journal of Environmental Research and Public Health ISSN 1660-4601 www.mdpi.com/journal/ijerph Article U.S. EPA Authority to Use Cumulative Risk Assessments in Environmental Decision-Making Sarah Alves 1,*, Joan Tilghman 2, Arlene Rosenbaum 3 and Devon C. Payne-Sturges 4 1 ICF International, 9300 Lee Highway, Fairfax, VA 22031, USA 2 ICF International, 2222 East NC-54, Beta Building, Suite 480, Durham, NC 27713, USA; E-Mail: JTilghman@icfi.com 3 ICF International, 4464 Hillview Way, Rohnert Park, CA 94928, USA; E-Mail: ARosenbaum@icfi.com 4 National Center for Environmental Research, U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Mail Code 8723P, Washington, DC 20460, USA; E-Mail: payne-sturges.devon@epa.gov * Author to whom correspondence should be addressed; E-Mail: SAlves@icfi.com; Tel.: +1-703-934-3534; Fax: +1-703-934-3730. Received: 17 January 2012; in revised form: 25 April 2012 / Accepted: 26 April 2012 / Published: 25 May 2012 Abstract: Conventionally, in its decision-making, the U.S. EPA has evaluated the effects and risks associated with a single pollutant in a single exposure medium. In reality, people are exposed to mixtures of pollutants or to the same pollutant through a variety of media, including the air, water, and food. It is now more recognized than before that environmental exposure to pollutants occurs via multiple exposure routes and pathways, including inhalation, ingestion, and dermal absorption. Moreover, chemical, biologic, radiologic, physical, and psychologic stressors are all acknowledged as affecting human health. Although many EPA offices attempt to consider cumulative risk assessment and cumulative effects in various ways, there is no Agency-wide policy for considering these risks and the effects of exposure to these risks when making environmental decisions. This article examines how U.S. courts might assess EPA’s general authority and discretion to use cumulative risk assessment as the basis for developing data in support of environmental decision-making, and how courts might assess the validity of a cumulative risk assessment methodology itself.