Int. J. Environ. Res. Public Health 2012, 9 2015 9. Protection of Environment. Code of Federal Regulations, Section 1508.7, Title 40, 2011. 10. Although EPA does not have an official definition for “cumulative effects,” and different organizations and scholars define this terms in different ways, the U.S. Council on Environmental Quality (CEQ) has defined the term “cumulative impact” for purposes of implementing the National Environmental Policy Act (NEPA). CEQ regulations state that a cumulative impact is “the impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency …or person undertakes such other actions. Cumulative impacts can result from individually minor but, collectively significant actions taking place over a period of time” [9]. The discussion of cumulative effects in this article is broader than the NEPA definition in that the concept here specifically encompasses the combined effects of different types of stressors via multiple exposure pathways, in addition to additive impacts over time. 11. The Law of Environmental Justice: Theories and Procedures to Address Disproportionate Risks, 2nd ed.; Berrard, M.B., Foster, S.R., Eds.; American Bar Association: Chicago, IL, USA, 2008. 12. Ethyl Corp. vs. EPA; 541 F.2d 1, D.C. Cir. 1976. 13. National Research Council (NRC). Science and Decisions: Advancing Risk Assessment; The National Academies Press: Washington, DC, USA, 2009. 14. National Environmental Justice Advisory Council. Ensuring Risk Reduction in Communities with Multiple Stressors: Environmental Justice and Cumulative Risks/Impacts; National Environmental Justice Advisory Council: Washington, DC, USA, 2004. 15. EPA’s Action Development Process: Interim Guidance on Considering Environmental Justice During The Development of an Action; U.S. Environmental Protection Agency, Office of Research and Development, U.S. Government Printing Office: Washington, DC, USA, 2010. 16. Sexton, K.; Olden, K.; Johnson, B.L. “Environmental justice”: The central role of research in establishing a credible scientific foundation for informed decision making. Toxicol. Ind. Health 1993, 9, 685–727. 17. Sexton, K. Sociodemographic aspects of human susceptibility to toxic chemicals: Do class and race matter for realistic risk assessment? Environ. Toxicol. Pharmacol. 1997, 4, 261–269. 18. Jacobs, D.E. Environmental health disparities in housing. Am. J. Public Health 2011, 101 (Suppl 1), S115–S122. 19. Institute of Medicine (IOM). Toward Environmental Justice: Research, Education, and Health Policy Needs; The National Academies Press: Washington, DC, USA, 1999. 20. Chakraborty, J.; Maantay, J.A.; Brender, J.D. Disproportionate proximity to environmental health hazards: Methods, models, and measurement. Am. J. Public Health 2011, 101 (Suppl 1), S27–S36. 21. Bullard, R.D.; Mohai, P.; Saha, R.; Wright, B. Toxic Wastes and Race at Twenty: 1987–2007. Grassroots Struggles to Dismantle Environmental Racism in the United States: Executive Summary; United Church of Christ, Justice and Witness Ministries: Cleveland, OH, USA, 2007. 22. Bullard, R.D. Dumping in Dixie: Race, Class and Environmental Quality; Westview Press: Boulder, CO, USA, 1990. 23. Brown, P. Race, class, and environmental health: A review and systematization of the literature. Environ. Res. 1995, 69, 15–30.