title: Cumulative risk assessment lessons learned: a review of case studies and issue papers.
abstract: Cumulative risk assessments (CRAs) examine potential risks posed by exposure to multiple and sometimes disparate environmental stressors. CRAs are more resource intensive than single chemical assessments, and pose additional challenges and sources of uncertainty. CRAs may examine the impact of several factors on risk, including exposure magnitude and timing, chemical mixture composition, as well as physical, biological, or psychosocial stressors. CRAs are meant to increase the relevance of risk assessments, providing decision makers with information based on real world exposure scenarios that improve the characterization of actual risks and hazards. The U.S. Environmental Protection Agency has evaluated a number of CRAs, performed by or commissioned for the Agency, to seek insight into CRA concepts, methods, and lessons learned. In this article, ten case studies and five issue papers on key CRA topics are examined and a set of lessons learned are identified for CRA implementation. The lessons address the iterative nature of CRAs, importance of considering vulnerability, need for stakeholder engagement, value of a tiered approach, new methods to assess multiroute exposures to chemical mixtures, and the impact of geographical scale on approach and purpose.
authors.affiliation: American Association for the Advancement of Science (AAAS) Science and Technology Policy Fellow, U.S. Environmental Protection Agency (EPA) Office of the Science Advisor, 1200 Pennsylvania Ave. NW., Washington, DC 20460, USA. Electronic address: gallagher.sarah@epa.gov.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Gallagher
authors.affiliation: U.S. EPA National Center for Environmental Assessment, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA.
authors.forename: Glenn E
authors.initials: GE
authors.lastname: Rice
authors.affiliation: U.S. EPA Office of Pollution Prevention and Toxics, 1200 Pennsylvania Ave. NW., Washington, DC 20460, USA.
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Scarano
authors.affiliation: U.S. EPA National Center for Environmental Assessment, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, USA.
authors.forename: Linda K
authors.initials: LK
authors.lastname: Teuschler
authors.affiliation: U.S. EPA Region 5 Air and Radiation Division, 77 W. Jackson Blvd., Chicago, IL 60604, USA.
authors.forename: George
authors.initials: G
authors.lastname: Bollweg
authors.affiliation: U.S. EPA Office of the Science Advisor, 1200 Pennsylvania Ave. NW., Washington, DC 20460, USA.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Martin
mesh_terms: D004781:Environmental Exposure; D006801:Humans; D018570:Risk Assessment / Q000379:methods* / Q000706:statistics & numerical data; D014481:United States; D014484:United States Environmental Protection Agency; D035862:Vulnerable Populations / Q000706:statistics & numerical data*
keywords: Chemical mixture; Cumulative risk assessment; Multiroute exposure; Stakeholder involvement; Tiered approach; Vulnerability