Dioxin
Dioxin is one of the most toxic chemicals known. 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." The
EPA report confirmed that dioxin is a cancer hazard to people; that exposure
to dioxin can also cause severe reproductive and developmental problems
(at levels 100 times lower than those associated with its cancer causing
effects); and that dioxin can cause immune system damage and interfere
with regulatory hormones.
The International Agency for Research on Cancer [IARC] --part of the
World Health Organization --announced February 14, 1997, that the most
potent dioxin, 2,3,7,8-TCDD, is a now considered a Class 1 carcinogen,
meaning a "known human carcinogen."
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.
Where it comes from
Dioxin is formed by burning chlorine-based chemical compounds with hydrocarbons.
The major source of dioxin in the environment (95%) comes from incinerators
burning chlorinated wastes. Dioxin pollution is also affiliated with paper
mills which use chlorine bleaching in their process and with the production
of Polyvinyl Chloride (PVC) plastics.
Health Effects
- Sperm count in men worldwide has dropped to 50% of what it was 50
years ago.
- The incidence of testicular cancer has tripled in the last 50 years,
and prostate cancer has doubled.
- Endometriosis - the painful growth outside the uterus of cells that
normally line the uterus - -which was formerly a rare condition, now
afflicts 5 million American women.
- In 1960, a woman's chance of developing breast cancer during her lifetime
was one in 20. Today the chances are one in eight.
Exposure
The major sources of dioxin are in our diet. Since dioxin is fat-soluble,
it bioaccumulates up the food chain and it is mainly (97.5%) found in
meat and dairy products (beef, dairy products, milk, chicken, pork,
fish and eggs in that order... see chart below). In fish alone, these
toxins bioaccumulate up the food chain so that dioxin levels in fish are
100,000 times that of the surrounding environment.
In EPA's dioxin report, they refer to dioxin as hydrophobic. This
means that dioxin, when it settles on water bodies, will avoid the water
and find a fish to go in to. The same goes for other wildlife. Dioxin
will find animals to go in to, working 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, and it is present in the fatty breast milk, which is also
a route of exposure which doses the infant, making breast-feeding for
non-vegetarian mothers quite hazardous.
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