Int. J. Environ. Res. Public Health 2012, 9 1998 Keywords: cumulative effects; cumulative risk; environmental justice; U.S. Environmental Protection Agency; statutory authority List of Abbreviations APA: CAA: CEQ: Cir.: D.C. Cir.: EIS: EJ: EO: EPA: FDA: FDCA: FR: NAAQS: NEJAC: NEPA: NRC: Administrative Procedure Act Clean Air Act Council on Environmental Quality Circuit U.S. Court of Appeals for the District of Columbia Circuit Environmental Impact Statement Environmental Justice Executive Order U.S. Environmental Protection Agency Food and Drug Administration Federal Food, Drug, and Cosmetic Act Federal Register National Ambient Air Quality Standard National Environmental Justice Advisory Council National Environmental Policy Act National Research Council 1. Introduction 1.1. The Movement toward Consideration of Cumulative Risks Historically, in its decision-making, the U.S. Environmental Protection Agency (EPA) has evaluated the risks and effects associated with exposure to a single pollutant in a single exposure medium. However, it is now more recognized than before that exposure to environmental pollutants occurs via multiple routes and pathways, including inhalation, ingestion, and dermal absorption [1,2]. Consequently, to arrive at a realistic assessment of exposure risks, regulatory authorities arguably should consider cumulative stressors [3–6] and exposure data derived from cumulative risk assessment [3,7,8]. Although many EPA offices attempt to consider cumulative effects [9,10] in various ways, there is no current Agency-wide policy to use a cumulative risk methodology to discern these effects when making environmental decisions. Some EPA offices make decisions as if they do not have the authority to use cumulative risk assessments. These office staff may believe that their authorizing statute, program implementation policies, or regulations specifically prohibit them from doing so. Further, although U.S. courts generally have accepted EPA’s authority under various statutes to use risk assessment as an analytic tool in decision-making, ([11], pp. 369–373; [12], p. 28), there has been