What health effects are associated with dioxin?
Tests on laboratory animals indicate that dioxin is one of the more toxic man-made compounds.1 Beyond cancer, 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 a detailed list of health problems related to dioxin, read the People's Report on Dioxin. 2
A new report from the National Academies of Science reaffirmed concern about dioxin and dioxin like compounds and suggests changes in the way the Environmental Protection Agency evaluates the risks of human exposure.3
Executive Summary: Health Risks from Dioxin and Related Compounds.
Where do dioxins come from?
Dioxins are produced as by-products of incineration, combustion, metal processing, chemical manufacturing and processing.3 They are hydrophobic (water-fearing) and lipophilic (fat-loving). This means dioxin compounds settling on rivers, lakes and other bodies of water will tend to accumulate in fish rather than remain in the water. Dioxins also bioaccumulate in other animals and wildlife building up through the food chain in the fat tissue of living organisms.4
How are people exposed?
Humans are exposed to dioxins primarily from eating foods, such as beef, dairy products, fish, shellfish, and pork.3 A typical North American diet receives 93% of dioxin exposure from meat and dairy products. 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 [parts per trillion]. ...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."4
Before they can become toxic to humans or animals, the compound must bind to a specific receptor, called the aromatic hydrocarbon receptor or Ah receptor. (The binding itself does not necessarily produce an adverse health effect, but is a necessary step.)3
Who is most at risk?
Infants and young children. Dioxin accumulates in fatty tissue and decays slowly. There's no way to rid it from our bodies. But pregnant and nursing women are an exception. They excrete dioxin through the placenta and through fatty breast milk. Both dose the baby, particularly for non-vegan/non-vegetarian mothers.5 (Consult your physician before altering your diet, especially if pregnant or nursing.)
What can we do?
In recent years, efforts to reduce the amount of dioxins in the environment have resulted in lower measured concentrations in the environment and in human blood.3 That means we can have a positive impact. And bringing the point home, we can reduce exposure to dioxin for ourselves and our families by limiting our intake of the fat found in milk, eggs and meat.
Reducing Dioxins in Milk
Non-skim milk also contains fat, and, organic or not, “animal fats are a concentrator of dioxin,” a known carcinogen that also may cause endocrine disruption, reproductive damage and birth defects, according to Jim McKean, a doctor of veterinary medicine at Iowa State University … Click for the full story from The Green Guide.6
How Much Dioxin is in Your Diet?
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.
Source: EPA Dioxin Reassessment Summary, 4/94 - Vol. 1, p. 37 (Figure II-5)
Dioxin Levels in U.S. Foods|
|Soft blue cheese
|Beef rib steak
|Soft cream cheese
|American cheese sticks
|Beef rib/sirloin tip
Source: "The American People's Dioxin Report," Technical Support Document, Center for Health, Environment and Justice. Table 4-1. November 1999.
1 EPA Glossary of Environmental Terms, U.S. Environmental Protection Agency.
2 "The American People's Dioxin Report," Technical Support Document, Center for Health, Environment and Justice. November 1999.
3 National Academies of Science. "Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment," National Academies Press, July 2006.
Link to Executive Summary
4 Arnold Schecter, “Intake of Dioxins and Related Compounds from Food in the U.S. Population,” Journal of Toxicology and Environmental Health, Part A, 63:1–18, 2001.