US EPA

Several reports have highlighted the importance of understanding the accumulation of risks from multiple environmental stressors. These include the National Research Council's 1994 report Science and Judgment in Risk Assessment and the 1997 report by the Presidential/Congressional Commission on Risk Assessment and Risk Management entitled Risk Assessment and Risk Management in Regulatory Decision-Making. In addition, legislation such as the Food Quality Protection Act of 1996, has directed the Environmental Protection Agency to move beyond single chemical assessments and to focus, in part, on the cumulative effects of chemical exposures occurring simultaneously. Further emphasizing the need for EPA to focus on cumulative risks are cases filed under Title VI of the 1964 Civil Rights Act. These cases have emphasized the need for a population-based approach to assessing human health risks from environmental contaminants.

In response to the increasing focus on cumulative risk, several EPA programs have begun to explore cumulative approaches to risk assessment. In 1997, The EPA Science Policy Council issued a guidance on planning and scoping for cumulative risk assessments (https://www.epa.gov/ORD/spc/2cumrisk.htm). More recently, the Office of Pesticide Programs has developed draft cumulative risk assessment guidance focused on implementing certain provisions of FQPA. The Office of Air Quality Planning and Standards has applied cumulative exposure models in its analyses for the National-Scale Air Toxics Assessment (NATA). In addition, community-specific cumulative risk assessment has been explored through the Agency's Cumulative Exposure Project. The EPA Science Policy Council has asked the Risk Assessment Forum to begin developing Agency-wide cumulative risk assessment guidance that builds from these ongoing activities. As a first step, a technical panel convened under the Risk Assessment Forum has been working to develop a Framework for Cumulative Risk Assessment. Building from the Agency's growing experiences, this Framework is intended to identify the basic elements of the cumulative risk assessment process. It should provide a flexible structure for the technical issues and define key terms associated with cumulative risk assessment.