Update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000 (2013, External Review Draft)


EPA is announcing the availability of the draft report, Update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000 for a 30-day public comment period. EPA also announced that an independent contractor will select and set up a group of experts to conduct a letter peer-review of the draft document. The deadline for comments is September 6, 2013. [Federal Register Notice August 7, 2013]


In 2006, EPA published an inventory of sources and environmental releases of dioxin-like compounds in the United States. This draft report presents an update and revision to that dioxin source inventory. It also presents updated estimates of environmental releases of dioxin-like compounds to the air, water, land and products. The sources are grouped into five broad categories: combustion sources, metals smelting/refining, chemical manufacturing, natural sources, and environmental reservoirs. Estimates of annual releases to land, air, and water are presented for reference years 1987, 1995, and 2000.

While the overall decreasing trend in emissions seen in the original report continues, the individual dioxin releases in this draft updated report are generally higher than the values reported in 2006. This is largely due to the inclusion (in all three years) of additional sources in the quantitative inventory that were not included in the 2006 report. The largest new source included in this draft updated inventory was forest fires. In the 2006 report, this was classified as preliminary and not included in the quantitative inventory. The top three air sources of dioxin emissions in 2000 were forest fires, backyard burning of trash, and medical waste incinerators.

Dioxins are toxic chemicals that naturally exist in the environment and can be released into the environment through forest fires, backyard burning of trash, certain industrial activities, and residue from past commercial burning of waste. When released into the air, dioxins may be transported long distances. Because of this, dioxins are found in most places in the world. Dioxins released to the air will settle onto vegetation and soil that are consumed by animals. Dioxins may enter water bodies through erosion and runoff or from direct discharge of wastes. When dioxins are released into water, they tend to settle into sediments where they can be further transported or ingested by fish and other aquatic organisms. Dioxins break down very slowly in the environment and can be deposited on plants and taken up by animals and aquatic organisms. Dioxins are lipophilic, which means they tend to accumulate in fats. Because of this, they may be concentrated in the food chain so that animals have higher concentrations than plants, water, soil, or sediments. Since humans are at the top of the food chain, our bodies have the highest concentrations of dioxins. Over the past two decades EPA has worked to reduce emissions from all of the major industrial sources of dioxins As a result of the efforts of EPA, state governments and industry, known and quantifiable total dioxin emissions in the U.S. have been reduced by about 75% from 1987 levels and emissions to air have been reduced by about 85% from 1987 levels.


Following the public comment period and external peer review, EPA will revise the document and post the final report on the EPA website.


U.S. EPA. Update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States for the Years 1987, 1995, and 2000 (2013, External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/005A, 2013.


1995EPA's Science Advisory Board (SAB) reviewed EPA's Dioxin Reassessment. The SAB recommended that EPA undertake a detailed assessment of sources of dioxin.
1998In response to the recommendation of the SAB, EPA released the first external review draft report entitled, The Inventory of Sources of Dioxin in the United States (EPA/600/P-98/002Aa).
1999EPA began the development of the year 2000 update to the dioxin inventory.
Jun 2001EPA released an electronic Database of Sources of Environmental Releases of Dioxin-Like Compounds in the United States containing dioxin emission factors specific for releases from sources in reference years 1987 and 1995.
May 2005EPA released the external review draft of the dioxin updated inventory for public comment and peer review. A panel of six internationally known experts convened in September to formally review and comment on the draft report.
Nov 2006The final inventory of Dioxin sources was released incorporating comments received from the public and the formal peer review panel.
Aug 2013EPA released a draft updated inventory of sources for public review and comment and external review. [Federal Register Notice Aug 7, 2013]

Additional Information

Comments on the assessment may be submitted and reviewed using the e-Government Regulations.gov Web site. From the site, select “Environmental Protection Agency” and the keyword “EPA-HQ-ORD-2011-0805 (for the docket ID) to comment on this report.

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.