Dioxins: Answering the Questions

A one in 1000 increased chance of cancer and a potential for adverse effects on reproduction and development . . . how bad are dioxins and what can be done about them? Battelle is helping government agencies and private industry address these issues. Dioxins, a term referring to a collective class of chemical compounds with similar chemical structures and similar ability to induce certain biological characteristics, include polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and certain polychlorinated biphenyls (PCBs). PCDDs and PCDFs are not intentionally produced, but instead are the result of a number of anthropogenic and a few natural processes. The most significant sources of PCDDs and PCDFs are associated with uncontrolled combustion, although these compounds can also be released from various industrial and manufacturing processes. PCBs, on the other hand, were once used as coolants and lubricants in electrical equipment, but are no longer manufactured in the United States. PCBs have left their legacy of environmental contamination from historic uses.

For the past decade, the U.S. Environmental Protection Agency (EPA) has worked on a Dioxin Reassessment in order to evaluate dioxin exposure and resulting human health effects. The Reassessment effort includes a comprehensive evaluation of sources, fate and transport, levels of human exposure, and toxic effects on humans and other animals. A large number of sources have been identified and characterized through this effort. Controls have been aimed at well-defined industrial sources such as incinerators and have resulted in significant reductions in new dioxin emissions. As EPA’s regulatory and voluntary initiatives have achieved success in reducing the primary sources of dioxin release, focus has turned to pathway intervention and identification of sources that most significantly impact the commercial food supply – the primary source of human exposure. Investigations have already begun to answer questions to help link sources and exposures.

For over 20 years, Battelle has conducted technical studies and analyses to support dioxin and persistant environmental contanimant research. Battelle is positioned to continue to help government and industry address the remaining concerns surrounding dioxins – whether related to source characterization and emission measurements, new analytical procedures, human exposure and ecological risk assessments, intervention studies, or regulatory and policy options. The ultimate goal for everyone is to manage all risks to acceptable levels by helping to target reduction efforts at sources and pathways that most significantly impact exposure and risk. This issue of Environmental Updates provides a snapshot of Battelle’s support to dioxin and persistent environmental contaminant research.