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#536 - Immune System Toxins, 05-Mar-1997

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

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

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

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,"
13, 1996), pgs. 1473-1479. The data describe the non-institutionalized

(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
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.

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,
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;