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E MAGAZINE (The Environmental Magazine) MAY/JUNE 2005
Pages 40-41
Green Living With The Earth in Mind
YOUR HEALTH
Auto Exposure: Do Immune System Diseases Have an Environmental Cause?
BY MELISSA KNOPPER
Nearly 20 years ago, as a young graduate student, Canadian wildlife
biologist Peter Ross investigated a massive die-off of harbor seals in the
Baltic Sea. The problem, it turned out, was their immune systems. Their
habitat was so full of polychlorinated biphenyls (PCBs), that the seals
could not fight common viruses anymore.
The more PCBs the seals had in their bodies, the greater damage scientists
found. PCBs wreak havoc on the delicate balance between hormones and the
immune system, Ross says. Now, scientists are studying similar effects of
toxic chemicals in humans.
A Clear Link
Researchers are uncovering a definite link between environmental pollutants
and a growing number of autoimmune diseases. Disorders like lupus, multiple
sclerosis (MS) and Type I diabetes are on the rise, says Glinda Cooper, an
epidemiologist with the National Institute of Environmental Health Sciences
(NIEHS). "It's very likely that environmental factors play a role in the
development of these diseases," Cooper says.
About eight percent of the U.S. population, or 22 million people, have one
of the 24 most common forms of autoimmune disease, National Institutes of
Health officials estimate. "You have to look at these diseases together to
really get the magnitude of the problem," says Virginia Ladd, president of
the Detroit-based American Autoimmune Related Disorders Association (AARDA).
Few people have heard of these disorders because, individually, they are
rare, Ladd says. Since AARDA lobbied to classify them as a group, government
officials are providing more research dollars.
Autoimmune diseases are the medical equivalent of friendly fire in the
military. They cause a person's immune system to go haywire and attack
healthy tissue. The site of attack varies: In MS, it's nerve cells; in
rheumatoid arthritis, it strikes the joints; lupus targets the kidneys,
joints, heart or lungs. Scientists are beginning to understand the cause.
It's partly genetic. But a person also must encounter something in the
environment (a virus, a chemical or a heavy metal) before symptoms appear.
Living with this kind of war raging inside your body can take its toll.
Autoimmune patients (75 percent are women) endure severe fatigue, swollen
joints and mysterious skin rashes. They live with constant discomfort and
unpredictable flare-ups. Many must give up careers they love, stop
exercising (or even climbing stairs), and have to let someone else take care
of their children much of the time. So little is known about these diseases,
there are few treatments.
Recent studies show many of the same chemicals that cause cancer and
reproductive problems in both humans and wildlife can also aggravate
autoimmune disease. In some cases, toxics set the disease in motion even
before an infant is born. Other scientists say it may take a combination of
factors. Here are their findings:
- Environmental estrogens/endocrine disrupters. According to World Wildlife
Fund scientist Theo Colborn, any substance that might act like hormones can
influence the immune system. Bisphenol A (BPA) is one such chemical. It's in
everything from computers to polycarbonate baby bottles. Past studies showed
BPA-which acts like estrogen-may increase breast cancer risk. Now,
scientists say it also may activate autoimmune responses.
Early evidence comes from a series of Japanese animal studies, in which lab
mice with a genetic tendency to get lupus developed telltale signs of the
disease when exposed to BPA. Meanwhile, Ansar Ahmed, a Virginia Tech
immunologist, found prenatal exposure to the drug DES (another estrogen-like
chemical) caused mice to develop lupus symptoms-but not until later in life.
When Kansas en- docrinologist Virginia Rider exposed immune cells of human
lupus patients to estrogen, the disease activity increased.
- Pesticides. Since many pesticides act like hormones, they also appear to
play a role in autoimmune disease. For example, Dr. Eric Sobel, a University
of Florida rheumatologist, exposed lab mice to chlordecone (a pesticide in
ant and roach traps). The mice came down with lupus.
- Mercury. At California's Scripps Research Institute, K. Michael Pollard
says mice with a lupus gene will develop the disease when exposed to the
level of mercury most of us carry in our bodies every day (0.04 micrograms).
"It's certainly a concern if you are someone with a family background of
autoimmune disease," Pollard says. "If you eat a lot of fish, you might want
to be careful about it." Similar experiments showed lupus-prone mice
developed the disease after taking a very high dose of thimerosal, the
mercury-based preservative in some vaccines. Pollard says no one has studied
how thimerosal might affect children with a family history of autoimmune
disease. But he believes the benefits of vaccines outweigh the risk.
Mice with the lupus gene also got the disease after receiving mercury-based
dental fillings. While the debate over the safety of dental amalgam in
general continues, people with a genetic risk for autoimmune disease could
be more sensitive to it, Pollard says.
- Work-related exposures. Occupational studies show stone workers and miners
have more rheumatoid arthritis, lupus, MS and scleroderma. These people
inhale silica dust. Auto workers and military staff who use a lot of
solvents also have higher rates of rheumatoid arthritis and MS. Several
lawsuits are underway that could implicate pesticides, asbestos and
radioactive bomb fallout.
Based on this new information, people with a family history of autoimmune
disease should take certain precautions, health experts say. While it's
impossible to avoid all toxics, here are a few ways to protect yourself:
- Get tested. If you re concerned, get an immune profile from a specialist.
- Ask about estrogen. Tell your doctor about your family history before you
start hormone therapy or the birth control pill. Estrogenic chemicals can
leak from plastic in the microwave, so use glass instead.
- Go veggie. Fatty meats and dairy products carry the most dioxin and PCBs.
Chicken contains estrogen.Vegetarian meals contain less toxins.
- Filter. Drinking water may contain solvents and other contaminants.
- Go organic. Avoid as many chemicals as possible. Buy organic produce,
unbleached paper products and greener cleaners; skip weed killer and bug
sprays.
- Manage stress. Intense emotional stress makes autoimmune diseases flare.
- Watch what you swallow. Herbs like Echinacea can be harmful if your immune
system already is in overdrive. Check with a doctor first.
The more scientists learn about environmental triggers, the more they will
be able to prevent autoimmune disease. Meanwhile, government agencies and
conservation groups must work to keep harmful pollutants out of the
environment in the first place, says seal researcher Ross, now with the
Canadian Department of Fisheries. "Its very hard to predict what impact
these chemicals are going to have when they end up in our waterways and food
supply," Ross says. "It speaks to the need for wise chemical design and
regulations." CONTACT: American Au- toimmune-Related Disorders Association
(AARDA), (586)776-3900, www.aarda. org; Lupus Foundation of America, (202)
349-1155, www.lupus.org; National Multiple Sclerosis Society, (800)
FIGHT-MS, www.nmss.org.
MELISSA KNOPPER is a Colorado-based freelance writer.
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