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IMMUNE
SYSTEM TOXINS
In 1987, about 45%
of Americans were living with one or more chronic conditions (a
term that includes chronic diseases and impairments). In 1935,
the proportion was 22%, so chronic conditions have approximately
doubled during the last 60 years. The majority of people with
chronic conditions are not disabled, nor are they elderly. In
fact, one out of every four children in the U.S. (25%) now lives
with a chronic condition.[1]
- Chronic conditions
can often be "managed" (helping people to live with the condition),
but they usually cannot be cured. The cost of chronic conditions
in 1990 was estimated to be $659 billion --nearly three quarters
of all U.S. health care costs. (To get this huge number into
perspective, it may help to know that the entire U.S. military
budget is $250 billion per year.)
Perhaps it is time
we looked seriously at prevention as an approach to chronic conditions.
- Humans and other
vertebrates (animals with a backbone) come equipped with a complicated
"immune system" which PREVENTS diseases that might be caused
by pathogens (bacteria, viruses, fungi, and parasites) or cancerous
cells. We are constantly exposed to hundreds of pathogens in
daily life, but our immune system recognizes them as dangerous
and swiftly isolates them and removes them from our bodies.
The immune system is a built-in disease-prevention mechanism
that works hard to keep us healthy so long as we keep our immune
system healthy.
- If the immune system
is damaged in certain ways, it can allow pathogens to overwhelm
our defenses and make us sick. Under other circumstances (which
are poorly understood), the immune system goes haywire and attacks
its host, causing major damage of a different kind, known as
"autoimmune" diseases. These "autoimmune" diseases include insulin-dependent
diabetes, multiple sclerosis, lupus erythematosus, schleroderma,
rheumatoid arthritis, and about a dozen others.[2] In these
diseases, the immune system attacks and breaks down the host
organism, causing prolonged misery and death.
A third class of immune
disorders is "hypersensitivity reactions," or allergic reactions,
such as asthma, hay fever (allergic rhinitis), and food allergies
(to milk, egg whites, peanuts, fish, soy and other foods), some
of which may be minor, others of which may be fatal.
- As early as 1984,
the U.S. National Toxicology Program [NTP] (within the U.S.
Department of Health and Human Services) observed that chemical
damage to the immune system could result in "hypersensitivity
or allergy" to specific chemicals or to chemicals in general.
NTP said damage to the immune system can have far-reaching consequences
for an individual, leaving him or her vulnerable to attack by
bacteria and viruses, at heightened risk of cancer, and even
predisposed to develop AIDS.[3]
- Unfortunately, during
the past 50 years, corporations have been permitted to release
more and more industrial chemicals and consumer products that
damage the immune systems of birds, amphibians, reptiles, fish,
and mammals, including humans. The immune system itself has
only been fully recognized since the 1950s, and it wasn't until
the 1970s that all the major components and activities of the
immune system were identified. Many of these are not well understood
even today.[2]
- Partly as a result
of this ignorance, public health authorities have still not
established consistent criteria for measuring damage to the
immune system,[4] which of course allows corporate polluters
a lot of "wiggle room" when they are asked to stop releasing
--or to clean up past releases of --immunotoxic chemicals such
as PCBs, cadmium (see REHW #179), and mercury (REHW #462). (PCBs
are a class of industrial chemicals outlawed in the U.S. in
1976 because of their dangerous properties. Unfortunately, large
quantities of them persist in the environment to this day, affecting
wildlife and humans.[5])
A new study of immunotoxic
chemicals affecting mammals appeared earlier this year in ENVIRONMENTAL
SCIENCE AND TECHNOLOGY, a publication of the American Chemical
Society.[6] Since 1987, large numbers of dolphins, seals, and
sea turtles have been killed by disease in the Atlantic Ocean,
the Gulf of Mexico, the North Sea, and the Mediterranean. (See
REHW #399.)
In this new study,
researchers examined carcasses of bottlenose dolphins found dead
on Atlantic and Gulf coast beaches in Florida, 1989-1994. They
found elevated levels of tin, a toxic metal that has been used
for the past 40 years to paint the bottoms of boats and ships
to prevent the growth of barnacles and slime. (The specific tin
compounds are tributyl tin, dibutyl tin, and monobutyl tin, together
called organotin compounds. Tributyl tin is added to paint to
prevent growth of organisms on ships' bottoms; it slowly degrades
into the other two compounds.) The tin found in bottlenose dolphins
was compared to the tin found in spotted dolphins, and pygmy sperm
whales, which spend their lives far offshore. The bottlenose dolphins
had higher levels of tin, presumably because they spend their
lives close to shore, where anti-fouling paint from boats and
ships has contaminated bottom sediments and local food chains.
The researchers conclude
that the tin compounds --which are well established immunotoxins
--combined with PCBs and the pesticide DDT, which are also found
at high levels in dolphins and which are also well-established
immunotoxins --together may have deprived the dolphins of their
main defense against disease, their immune systems. They then
succumbed to bacteria and viruses that they had previously been
able to live with.
Other common agents
and environmental contaminants known to harm the immune system
include:
- ** Ultraviolet
light from the sun --the kind of light that is increasing
in the northern latitudes of the Earth because chlorofluorocarbons
(CFCs) have damaged the planet's protective ozone shield 10
to 30 miles in the sky. (See REHW #246, #441.) Ultraviolet
sunlight striking the inhabited portions of the planet has
increased 5% to 10% in recent years. In sum, we are now all
taking a bath in a moderately immunotoxic agent.[7]
- ** Dioxin and
PCBs. As mentioned above, PCBs are a class of industrial chemicals
now outlawed in the U.S., but still present in many parts
of the environment at toxic levels. Dioxins are a class of
chemicals created as unwanted byproducts of incineration,
metal smelting, and the manufacture of many pesticides. Dioxins
and PCBs are carcinogenic and powerfully immunotoxic in many
animals, including humans. (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.")[8]
- In monkeys (marmosets),
changes in white blood cells associated with the immune system
can be measured at dioxin levels of 10 ng/kg (nanograms of
dioxin per kilogram of body weight) --25% below the dioxin
level already found in average Americans. Mice with body burdens
of 10 ng/kg --25% below the amount already found in you and
me --display an increased susceptibility to infections by
viruses, presumably because their immune system has been damaged.
(See REHW #463 and #414.)
- ** Agent orange
--the chemical used by the U.S. in Vietnam to defoliate the
jungle, damages the immune system. Furthermore, Vietnam veterans
have an above-average likelihood of being struck by diabetes
--a serious immune system disease. (REHW #463.) In the general
population in the U.S., the incidence (occurrence) of diabetes
doubled between 1964 and 1981.[9] It is worth noting that
Agent orange is composed of two pesticides, 2,4,5-T and 2,4-D.
Though 2,4,5-T was banned in the U.S. in the early 1980s for
fear of birth defects, 2,4-D is still most the popular herbicide
used to kill broad-leaf weeds, such as dandelions, in lawns
today. After people spray 2,4-D on their lawn, it is carried
indoors on the family dog and on children's feet. Once indoors,
it contaminates rugs and carpets and persists for a very long
time. (REHW #436)
- ** Many pesticides
damage the immune system. In 1996, a study of pesticides and
the immune system, published by the World Resources Institute
(WRI), examined a growing body of literature from around the
world, showing that many common pesticides degrade the immune
systems of laboratory animals, wildlife, and humans.[10]
- WRI examined
studies of all major classes of pesticides --organochlorines
such as DDT, organophosphates such as malathion, and carbamates
such as aldicarb. All three classes were immunotoxic.
- ** Living near
a toxic dump damages the immune system in some people, though
these effects have been rarely studied. (REHW #272) ** Exposure
to fibers of asbestos and fiber glass damages the immune system.
(REHW #444.)
- These effects
may be more common than, and perhaps more important than,
cancer caused by exposure to such fibers, but have been largely
ignored in favor of cancer studies.
- ** Organochlorine
chemicals, including those known as "endocrine disrupters,"
damage the immune system. The endocrine (hormone) system strongly
influences the immune system, so chemicals that mimic hormones
may disrupt immune functions.[11] In addition, common chlorine-containing
chemicals such as perchloroethylene (dry cleaning fluid),
trichlorethylene (a common industrial solvent), and chloroform
(created in drinking water when it is chlorinated to kill
germs) can damage the immune system. (REHW #279, #365, #399)
Since 1970, the U.S.
has spent 98% of its health dollars trying to cure diseases, and
only 2% trying to prevent them.[12] During this same period, many
diseases connected to the immune system such as asthma (REHW #218,
#374) and diabetes have increased dramatically, and deaths from
infectious diseases (not including AIDS) have increased 22%. (REHW
#528) These seem to be strong indications that immune disorders
are increasing. Perhaps all these immunotoxins are having a cumulative
effect.
The U.S. government
does not seem prepared to cope with these problems. To prevent
damage to the immune system would require strong action to curb
the release of immunotoxic chemicals into the environment. This
would require a government that is independent of, and stronger
than, the corporations releasing the chemicals. At present we
do not have anything close to that kind of government.
--Peter Montague
(National Writers Union,
UAW Local 1981/AFL-CIO)
===============
[1] Catherine
Hoffman and others, "Persons With Chronic Conditions," JOURNAL
OF THE AMERICAN MEDICAL ASSOCIATION Vol. 276, No. 18 (November
13, 1996), pgs. 1473-1479. The data describe the non-institutionalized
population. [2] William R. Clark, AT WAR WITHIN; THE DOUBLE-EDGED
SWORD OF IMMUNITY (New York: Oxford University Press, 1995). Clark
lists autoimmune diseases on pg. 123. [3] U.S. Department of Health
and Human Services, Public Health Service, National Toxicology
Program, FISCAL YEAR 1984 ANNUAL PLAN (Research Triangle, N.C.:
National Toxicology Program [P.O. Box 12233, Research Triangle
Park, NC 27709], 1984), pg. 157. [4] Anna Fan, Robert Howd, and
Brian Davis, "Risk Assessment of Environmental Chemicals," ANNUAL
REVIEW OF PHARMACOLOGY AND TOXICOLOGY Vol. 35 (1995), pgs. 341-368.
[5] See, for example, Andrew C. Revkin, "New Studies Show PCB's
[sic] Persist in Hudson, and Are Entering Air," NEW YORK TIMES
February 22, 1997, pg. A1. [6] K. Kannan and others, "Elevated
Accumulation of Tributyltin and Its Breakdown Products in Bottlenose
Dolphins (TURSIOPS TRUNCATUS) Found Stranded along the U.S. Atlantic
and Gulf Coasts," ENVIRONMENTAL SCIENCE & TECHNOLOGY [ES&T] Vol.
31, No. 1 (1997), pgs. 296-301. [7] And see A.J. McMichael and
others, editors, CLIMATE CHANGE AND HUMAN HEALTH (Geneva, Switzerland:
World Health Organization, 1996), Chapter 8, especially pages
167-170. [8] According to the press statement, the new IARC finding
on dioxin will be published in Volume 69 of IARC MONOGRAPHS ON
THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS. The IARC can be
contacted at: IARC, 150 Cours Albert Thomas, 69372 Lyon, France.
[9] National Diabetes Data Group, DIABETES IN AMERICA [NIH Publication
No. 85-1468] (no place of publication [Bethesda, Md.?]: U.S. Department
of Health and Human Services, Public Health Service, National
Institutes of Health, National Institute of Arthritis, Diabetes,
and Digestive and Kidney Diseases, August 1985), Table 2, pgs.
VI-4, VI-5. [10] Robert Repetto and Sanjay S. Baliga, PESTICIDES
AND THE IMMUNE SYSTEM: THE PUBLIC HEALTH RISKS (Washington, D.C.:
World Resources Institute, 1996). Available for $14.95 from WRI
Publications, P.O. Box 4852, Hampden Station, Baltimore, MD 21211.
Telephone: 1-800-822-0504, or (410) 516-6963. Fax: (410) 516-6998.
E-mail: chrisd@wri.org. [11] William R. Clark, AT WAR WITHIN;
THE DOUBLE-EDGED SWORD OF IMMUNITY (New York: Oxford University
Press, 1995), Chapter 8. See also: Phyllis B. Blair and others,
"Disease Patterns and Antibody Responses to Viral Antigens in
Women Exposed IN UTERO to Diethylstilbestrol," in Theo Colborn
and Coralie Clement, editors, CHEMICALLY-INDUCED ALTERATIONS IN
SEXUAL AND FUNCTIONAL DEVELOPMENT: THE WILDLIFE/HUMAN CONNECTION
[Advances in Modern Environmental Toxicology Vol. XXI] (Princeton,
N.J.: Princeton Scientific Publishing Co., 1992), pgs. 283-288.
And, in the same volume, see Phyllis B. Blair, "Immunologic Studies
of Women Exposed IN UTERO to Diethylstilbestrol," pgs. 289-294.
[12] Speech by Gilbert Omenn, Dean, School of Public Health and
Community Medicine, University of Washington, given at the meeting
of Grantmakers in Health, Fort Lauderdale, Florida, February 27,
1997. Descriptor terms: chronic diseases; immune system; children;
health care costs; prevension; diabetes; multiple schlerosis;
lupus erythematosus; schleroderma; rheumatoid arthritis; arthritis;
hypersensitivity reactions; allergies; national toxicology program;
cancer; bacteria; viruses; fungi; parasites; corporations; dolphins;
marine mammals; gulf of mexico; atlantic ocean; tributyltin; tin;
pcbs; ddt; uvb; ultraviolet radiation; cfcs; chlorofluorocarbons;
dioxin; carcinogens; iarc; international agency for research on
cancer; world health organization; who; agent orange; vietnam
veterans; 2,4,5-t; 2-4,d; herbicides; perticides; world resources
institute; wri; toxic dumps; landfilling; asbestos; fiberglass;
endocrine disrupters; endocrine system; perchloroethylene; trichloroethylene;
chloroform; asthma; infectious diseases;
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