1 A ffi £ I * 1W&& Sponsored by the National EPA-Tribal Science Council and hosted by the Grand Traverse Band of Ottawa and Chippewa Indians. 'W 2010 National Tribal science Forum Grand Traverse Resort and Spa, Traverse crtyT Michigan THEME: Mother Earth: Indigenous Knowledge ,« < and Science to Promote Positive Change ^at Title of Priority: Dioxin and Dioxin-like Compounds Summary of the Priority and Tribal Request: Tribes may be disproportionately affected by chemical contaminants in the environment through their practices for resource use relating to traditional life ways. When tribal resources are contaminated, the effects extend beyond impacts to human health and the ecosystem to issues of tribal culture and spirituality. Objective/Purpose of the Response: The purpose of this fact sheet is to provide information on EPA programs related to dioxin and dioxin-like compounds that address chemical stressors and to assist tribes in reducing frequency and the extent and nature of impacts. Tribes are particularly interested in understanding the current state-of-the-science relating to dioxins and dioxin-like compounds that might impact tribal health and well-being, particularly with diet and cultural practices that may leave them at risk to environmental exposures. The Tribal Science Council (TSC) first identified dioxin as a tribal science priority in 2002 when TSC tribal representatives were interested in learning the status of EPA's dioxin reassessment and in lending support to the effort to make the assessment more accurate for tribal populations. In 2004, the TSC agreed that the dioxin science priority should be expanded to encompass issues associated with dioxin and dioxin-like compounds, including: • Dioxin reassessment and reference dose • Dioxin-like poly chlorinated biphenyls (PCBs) (co-planars) • Burn barrels (air emissions) • Chlorinated bleaching from pulp and paper mills (air emissions and water discharges) • World Health Organization's Toxic Equivalents (used in human health and ecological evaluations). Based on this scope, the TSC tribal representatives developed a list of requests related to research and education on these topics. The representatives requested more information on these issues: • What toxic equivalents are and how they are derived • Sources of dioxins and dioxin-like compounds and how these compounds are regulated • Major exposure pathways that would affect tribes. Summary of EPA Response to Tribal Request: The term dioxin is commonly used to refer to a family of toxic chemicals that all share a similar chemical structure and a common mechanism of toxic action. This family includes 7 of the polychlorinated dibenzodioxins (PCDDs), 10 of the polychlorinated dibenzofurans (PCDFs) and 12 of the PCBs. PCDDs and PCDFs are not commercial chemical products but are trace-level unintentional byproducts of most forms of combustion and several industrial chemical processes. Dioxin levels have been declining since the early 1970s and have been the subject of federal and state regulations and clean-up actions. Because dioxins are widely distributed throughout the environment in low concentrations, are persistent and bioaccumulated, most people have detectable levels of dioxins in their tissues. These levels, in the low parts per trillion, have accumulated over a lifetime and will persist for years, even if no additional exposure were to occur. This background exposure is likely to result in an increased risk of cancer and is uncomfortably close to levels that can cause subtle adverse non-cancer effects in animals and humans. 1 ------- Suggested Next Steps: • Develop a comprehensive strategy to address dioxin and dioxin-like compounds in tribal communities. • Develop an implementation plan for the strategy. 2 ------- |