What is dioxin?

Dioxins and furans are some of the most toxic chemicals known to science. A draft report released for public comment in September 1994 by the US Environmental Protection Agency clearly describes dioxin as a serious public health threat. The public health impact of dioxin may rival the impact that DDT had on public health in the 1960's. According to the EPA report, not only does there appear to be no "safe" level of exposure to dioxin, but levels of dioxin and dioxin-like chemicals have been found in the general US population that are "at or near levels associated with adverse health effects."

Dioxin is a general term that describes a group of hundreds of chemicals that are highly persistent in the environment. The most toxic compound is 2,3,7,8-tetrachlorodibenzo-p-dioxin or TCDD. The toxicity of other dioxins and chemicals like PCBs that act like dioxin are measured in relation to TCDD. Dioxin is formed as an unintentional by-product of many industrial processes involving chlorine such as waste incineration, chemical and pesticide manufacturing and pulp and paper bleaching. Dioxin was the primary toxic component of Agent Orange, was found at Love Canal in Niagara Falls, NY and was the basis for evacuations at Times Beach, MO and Seveso, Italy.

Dioxin is formed by burning chlorine-based chemical compounds with hydrocarbons. The major source of dioxin in the environment comes from waste-burning incinerators of various sorts and also from backyard burn-barrels. Dioxin pollution is also affiliated with paper mills which use chlorine bleaching in their process and with the production of Polyvinyl Chloride (PVC) plastics and with the production of certain chlorinated chemicals (like many pesticides).

Does dioxin cause cancer? Yes. The EPA report confirmed that dioxin is a cancer hazard to people. In 1997, the International Agency for Research on Cancer (IARC) -- part of the World Health Organization -- published their research into dioxins and furans and announced on February 14, 1997, that the most potent dioxin, 2,3,7,8-TCDD, is a now considered a Group 1 carcinogen, meaning that it's a known human carcinogen. Also, in January 2001, the U.S. National Toxicology Program upgraded 2,3,7,8-TCDD from "Reasonably Anticipated to be a Human Carcinogen" to "Known to be a Human Carcinogen." See their reports on dioxins and furans from their 11th Report on Carcinogens (find related documents under 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and Furan). Finally, a 2003 re-analysis of the cancer risk from dioxin reaffirmed that there is no known "safe dose" or "threshold" below which dioxin will not cause cancer. A July 2002 study shows dioxin to be related to increased incidence of breast cancer. What other health problems are linked to dioxin exposure? In addition to cancer, exposure to dioxin can also cause severe reproductive and developmental problems (at levels 100 times lower than those associated with its cancer causing effects). Dioxin is well-known for its ability to damage the immune system and interfere with hormonal systems. Dioxin exposure has been linked to birth defects, inability to maintain pregnancy, decreased fertility, reduced sperm counts, endometriosis, diabetes, learning disabilities, immune system suppression, lung problems, skin disorders, lowered testosterone levels and much more. For an detailed list of health problems related to dioxin, read the People's Report on Dioxin. How are we exposed to dioxin? The major sources of dioxin are in our diet. Since dioxin is fat-soluble, it bioaccumulates, climbing up the food chain. A North American eating a typical North American diet will receive 93% of their dioxin exposure from meat and dairy products (23% is from milk and dairy alone; the other large sources of exposure are beef, fish, pork, poultry and eggs). In fish, these toxins bioaccumulate up the food chain so that dioxin levels in fish are 100,000 times that of the surrounding environment. The best way to avoid dioxin exposure is to reduce or eliminate your consumption of meat and dairy products by adopting a vegan diet. According to a May 2001 study of dioxin in foods, "The category with the lowest [dioxin] level was a simulated vegan diet, with 0.09 ppt.... Blood dioxin levels in pure vegans have also been found to be very low in comparison with the general population, indicating a lower contribution of these foods to human dioxin body burden." In EPA's dioxin report, they refer to dioxin as hydrophobic (water-fearing) and lipophilic (fat-loving). This means that dioxin, when it settles on water bodies, will rapidly accumulate in fish rather than remain in the water. The same goes for other wildlife. Dioxin works its way to the top of the food chain. Men have no ways to get rid of dioxin other than letting it break down according to its chemical half-lives. Women, on the other hand, have two ways which it can exit their bodies: It crosses the placenta... into the growing infant;

It is present in the fatty breast milk, which is also a route of exposure which doses the infant, making breast-feeding for non-vegan/vegetarian mothers quite hazardous. If you're eating the typical North American diet, this is where you are getting your dioxin from:

Chart from EPA Dioxin Reassessment Summary 4/94 - Vol. 1, p. 37

(Figure II-5. Background TEQ exposures for North America by pathway) [A TEQ is a dioxin Toxic EQuivalent, calculated by looking at all toxic dioxins and furans and measuring them in terms of the most toxic form of dioxin, 2,3,7,8-TCDD. This means that some dioxins/furans might only count as half a TEQ if it's half as toxic as 2,3,7,8-TCDD.] Levels of Dioxin in U.S. Food Supply (1995): [Chart from May 2001 study by Arnold Schecter et. al., Journal of Toxicology and Environmental Health, Part A, 63:1–18] Note: freshwater fish were farm-raised on a diet of meat, which is why they show the highest dioxin levels in this study. For more information on dioxin in the food supply... Intake of Dioxins and Related Compounds from Food in the U.S. Population

(May 2001 study in the Journal of Toxicology and Environmental Health showing ongoing high levels of dioxins in meat and dairy products)

(May 2001 study in the Journal of Toxicology and Environmental Health showing ongoing high levels of dioxins in meat and dairy products) How Toxic is Your Diet?

Dioxins and Dioxin-like Compounds in the Food Supply: Strategies to Decrease Exposure (National Academy of Sciences, 2003)

Dioxin/PCB contamination scandal in the Belgium and European food supply (1999)

EPA's Dioxin Reassessment Report and Related Government Documents Where Dioxin Comes From: An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the U.S. for the Years 1987, 1995, and 2000 (Final, Nov 2006) 8 MB PDF version 55 MB PDF version

Inventory of Sources and Environmental Releases of Dioxin-Like Compounds in the United States: The Year 2000 Update (External Review Draft, March 2005)

Database of Sources of Environmental Releases of Dioxin-Like Compounds in the United States (March 2001)

Inventory of Sources of Dioxin in the United States (External Review Draft, April 1998) Health Effects Reports: EPA’s Reanalysis of Key Issues Related to Dioxin Toxicity and Response to NAS Comments, Volume 1 (Feb 2012)

Dioxins and their effects on human health - World Health Organization fact sheet (May 2010)

National Academy of Sciences report: EPA Dioxin Assessment Understates Uncertainties, May Overstate Cancer Risk (see press release (National Academy of Sciences, July 2006)

Draft Dioxin Reassessment as submitted to National Academy of Sciences for their review (October 2004)

Draft Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds (September 2000)

Dioxin Environmental Assessment

Original 1994 EPA Draft Dioxin Reassessment -- Estimating Exposure

Original 1994 EPA Draft Dioxin Reassessment -- Risk Characterization

Original 1994 EPA Draft Dioxin Reassessment -- Health Assessment Documents (a scanned version of the original is available at the bottom of this page on EPA's site) Read about the convoluted nearly 25+ year history of EPA's dioxin reassessment to learn why it is still not out in final form. For more details on this, read the Behind Closed Doors report about the chemical industry's efforts to block final release of EPA's dioxin report. U.S. General Accounting Office (GAO) Reports: Environmental Health Risks: Information on EPA's Draft Reassessment of Dioxins (April 2002 report reaffirming that EPA's science is sound)

[Read the Alliance for Safe Alternatives' Summary of the Report)]

[Read the Alliance for Safe Alternatives' Summary of the Report)] "EPA's Science Advisory Board Panels: Improved Policies and Procedures Needed to Ensure Independence and Balance" (June 2001)

[Read the Alliance for Safe Alternatives' Summary of the Report]

Dioxins and Incineration: Metals as Catalysts for Dioxin Formation

Continuous Emissions Monitoring of Dioxins

Electrostatic Precipitators (ESPs) Breed Dioxins (ESPs are a type of pollution control device used in some incinerators) Anti-Incineration Links: Incineration and Incinerators-in-Disguise

Global Anti-Incinerator Alliance (GAIA) Waste Incineration: A Dying Technology An Industry Blowing Smoke: 10 Reasons Why Gasification, Pyrolysis & Plasma Incineration are Not "Green Solutions" (June 2009) GAIA's Publications Page - Other Great Reports on Incineration Issues GAIA's Incineration Factsheets

Greenpeace Anti-Incineration Resources Chlorine, Combustion and Dioxins: Does Reducing Chlorine in Wastes Decrease Dioxin Formation in Waste Incinerators? The Problem with Incineration Types of Incineration Alternatives to Incineration Incineration and Human Health Report The Construction Cost of Municipal Waste Incinerators - Counter Measures against Dioxin. The Entire Picture of Domestic Expenditure and Its Trend (May 2001)

Largest Known Dioxin Air Pollution Source (Harrisburg, PA Trash Incinerator) Closed in June 2003 (though a new incinerator has been built in its place) Environmental Research Foundation's

RACHEL's Environment & Health Weekly Issues Dioxin & Incineration

Dioxin & Health Effects

Dioxin Politics

Dioxin-Related Email Lists / Archives

Ban Toxics List:

There used to be an email list called "dioxin-l" which no longer exists, but its archives are available at the following pages: