Реферат на тему Dioxin Pollution Essay Research Paper Dioxin is
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Dioxin Pollution Essay, Research Paper
Dioxin is one of the most toxic chemicals known.
A 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.
(http://www.enviroweb.org/issues/dioxin/index.html)
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. The most conspicuous
source of dioxin pollution is from paper mills which
may pollute nearby streams with wastewater. Fish
living downstream from paper processing plants
have been found to contain significant amounts of
dioxin in their tissues.
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.
Dioxin has been know to cause cancer in many
different cases such as in explosion at a
Hoffman-LaRoche chemical plant in Seveso, Italy,
in 1976. People did not have any signs of cancer
at first. So everyone said look at Seveso dioxin
does not cause cancer. Now a new study in the
journal EPIDEMIOLOGY reveals that people
exposed to dioxin during the Seveso explosion
have begun to exhibit excessive numbers of cancer
cases. Dr. Linda Birnbaum, director of
environmental toxicology for U.S. EPA now says
that this case is just another strike against dioxin.
The area around Seveso has been divided into
three zones, called A, B and R. The small A zone
was most heavily contaminated, but its 724
residents were evacuated. ("Heavy" contamination
means that each square yard of land contained 13
to 494 micrograms of dioxin; a microgram is a
millionth of a gram and there are 28 grams in an
ounce.) The B zone was less heavily contaminated
but its 4824 residents were not evacuated; zone B
contained 43 micrograms of dioxin per square
yard of soil, or less. The R zone was even less
contaminated (average contamination being 4.3
micrograms per square yard), so its 31,647
residents were probably exposed to low levels.
Another 181,579 people living beyond zone R
serve as a control group living in
"noncontaminated" areas. The greatest cancer
increase has occurred in zone B. In zone A the
numbers are small and no significant cancer
increases have occurred. In zone R one kind of
cancer has increased: soft tissue sarcoma.
Previous studies have linked dioxin exposure to
soft tissue sarcoma in humans.
In zone B, among women there has been an
observable increase in cancers of the gall bladder
and bilary tract (the system that delivers bile from
the liver to the small intestine), and in cancers
related to the blood-forming system (multiple
myeloma and myeloid leukemia). Among men in
zone B, there were observable increases in
cancers of the blood-forming system, and in one
kind of non-Hodgkin’s lymphoma (a cancer of the
lymph system called lymphoreticulosarcoma). This
new study only covers the period 1976 through
1986–10 years after the Seveso accident. Since
most cancers take longer than 10 years to
develop, the cancers reported in this study may
represent only the earliest signs of more trouble to
come.
During routine preparation of a REPORT TO
CONGRESS ON CEMENT KILNS, the U.S.
Environmental Protection Agency (EPA) has
learned that cement and cement kiln dust contain
dioxins and furans (both of which are powerful
poisons in animals and humans). Cement is a
principal component of pipe often used to
distribute drinking water in many American cities.
Cement kiln dust is a byproduct of cement
manufacture and is routinely given or sold to
farmers as a soil treatment, or is discarded into
pits or is piled on the ground near cement kilns in
an uncontrolled fashion.
Many U.S. soldiers came in contact with dioxin
when it was used in the Vietnam War as a
defoliant under the name of Agent Orange. Now
many of these soldiers are showing signs of or
have cancer. Many of these soldiers have passed
on this dioxin poisoning to their children. For
years, Vietnam Veterans have claimed that their
exposure to Agent Orange has resulted in illness
and death. The United States government and the
Veterans Administration has consistently taken the
position that adequate information does not exist
to demonstrate a relationship with Vietnam
service, Agent Orange exposure and any illness or
disease.
In conclusion I feel that dioxins are very harmful
and not needed in society today. I also feel that
more steps need to be taken towards getting rid of
dioxins and monitoring where illness related to
dioxins are located. I also feel that many of the
men in the Vietnam War are getting sick and dying
as a result of dioxins that were used in Agent
Orange. The EPA should make sure that dioxin
levels are to high in any one area.