Dioxins and Furans

Dioxins and furans are two very similar groups of polyhalogenated compounds that are well-known toxic and persistent pollutants. Often the term "dioxins" refers to both dioxins and furans. The most well-studied compound is 2,3,7,8-tetrachlorodibenzo-p-dioxin or TCDD. Dioxin is formed as a by-product of many industrial processes that involve chlorine including waste incineration, chemical and pesticide manufacturing and pulp and paper bleaching. This family includes seven of the polychlorinated dibenzo dioxins (PCDDs) and ten of the polychlorinated dibenzo furans (PCDFs). Another group of chemicals, polychlorinated biphenyls (PCBs), are also very similar to dioxins and furans. At very low levels, dioxin can change the way cells grow and develop. Scientists claim that one form of dioxin causes cancer in humans. Some other human health effects include reproductive problems and birth defects. Dioxins and furans are both included in Annex C in the Stockholm Convention on Persistent Organic Pollutants, which means that "parties must take measures to reduce the unintentional releases of chemicals listed under Annex C with the goal of continuing minimization and, where feasible, ultimate elimination." According to the President's Cancer Panel, published in May 2010, dioxins are strongly linked to lung cancer, non-hodgkin lymphoma, and soft tissue sarcoma. Additionally, they are a suspected cause of breast cancer, prostate cancer, and multiple myeloma.

Sources of Dioxins and Furans
According to the EPA, dioxins and furans enter the environment from the incineration of municipal waste and medical waste, secondary copper smelting, forest fires, land application of sewage sludge, cement kilns, coal fired power plants, residential wood burning, chlorine bleaching of wood pulp, and perhaps backyard burning of household waste. According to the Natural Resources Defense Council (NRDC), "sewage sludge... is the largest source for dioxin exposure in the nation after backyard trash burning." (emphasis added)

Dangerous Levels of Dioxins Found in Sewage Sludge "Compost"
In 2010, a test found 65.97 TEQ of dioxins in the sewage sludge-based "compost" product Amend, made by Kellogg Garden Products. Amend is sold at Home Depot, Lowes, and nurseries on the west coast, advertised as a compost intended for flower and use in vegetable gardens.

NRDC Calls for Stricter Regulation of Dioxins in Sewage Sludge
In 2003, the EPA announced that it would not regulate dioxins in sewage sludge applied to land as fertilizer, even when used on farms and gardens where food is grown. The Natural Resources Defense Council (NRDC) criticized this decision, saying it violates the Clean Water Act.


 * "Dioxins cause cancer and diabetes, as well as nervous system and hormonal problems," said Nancy Stoner, director of NRDC's Clean Water Project. "And the EPA is required by law to protect the public from toxic pollutants like dioxins. This decision shows the agency under this administration has forgotten its mission."

Stoner added:


 * "EPA traditionally limits public exposure to chemicals if they pose a cancer risk of one per 1 million Americans," Stoner explained. "But the risk is 1 in 10,000 from the dioxins we already have in our bodies. And cancer isn't the only problem. The EPA itself has said that the non-cancer risks of dioxins are so high that it can't even calculate a 'safe' or acceptable level of exposure. To us that says EPA should keep dioxins out of our food, and that means, among other things, regulating sewage sludge."

NRDC called on the EPA to do the following:


 * "Prohibit sludge application on land used for pasture or growing forage food for livestock that will be consumed by humans;
 * "Set a dioxins limit at 1 in one million cancer risk to protect public health;
 * "Ban land application to sites where dioxin levels in the soil [exceed] 1 parts per trillion (based on ecological risks that cannot be alleviated by management measures, such as banning application to pasture lands, which would reduce risks to human health); and
 * "Require pollution prevention programs for sludges with detectible amounts of dioxins."

Unusual Dioxins From Triclosan
The antibacterial agent triclosan, commonly found in antibacterial soaps and other household products, can break down into a number of dioxins in the environment, including 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD), 2,3,7-trichlorodibenzo-p-dioxin (2,3,7-TCDD), 1,2,8-trichlorodibenzo-p-dioxin (1,2,8-TriCDD), and 1,2,3,8-tetrachlorodibenzo-p-dioxin (1,2,3,8-TCDD). The 2010 study that revealed this found that over the last 30 years, "the levels of the four dioxins derived from triclosan have risen by 200 to 300 percent, while levels of all the other dioxins have dropped by 73 to 90 percent." Researchers say these compounds “represent a previously unrecognized and increasingly important source of di-, tri-, and tetrachlorinated dibenzo-p-dioxins.”

Related SourceWatch articles

 * Sewage sludge
 * Biosolids
 * Food Rights Network

External articles

 * Marty Coyne, "Solid Waste: EPA 'Closes Book' by Not Regulating Dioxins in Sludge," Greenwire, October 20, 2003.
 * Michael Kilian, "EPA won't regulate dioxin-tainted sludge; Critics argue that risk of disease too high to ease rules," Chicago Tribune, October 18, 2003.