What Chemicals Are Lurking Inside Your Body?
Chemicals, toxins, and other dangerous substances exist throughout our environments -- and you may be surprised by how many end up inside your body.
By Dulce Zamora
Reviewed By Brunilda Nazario
Charlotte Brody feels violated and angry. After years of buying organic products and rejecting artificial chemicals in her gardening, she discovers the presence of the pesticide Dursban in her body.
The chemical, used to treat lawns and turfs and to kills termites and mosquitoes, is linked to neurological problems.
"I have longed for Dursban at times," says Brody, describing the pains she has taken to remove weeds by hand. "To find out I really couldn't stay away from Dursban really troubled me."
Brody learned of her exposure to the now-banned pesticide after participating in a study in which researchers at two major laboratories found an average of 91 industrial compounds, pollutants, and other chemicals in the blood and urine of nine volunteers.
The volunteers did not work with chemicals in their jobs and did not live near an industrial facility.
The list includes compounds found in insecticides, cosmetic and personal-care products, cleaning solutions, paint, fuel, and industrial pollutants such as PCBs and dioxin. Many have been linked to cancer in animals or humans, and about half are toxins or cause birth defects.
Some of the subjects were surprised to hear they had stuff like lead, arsenic, and flame-retardants in their system, what some experts refer to as a person's "body burden."
Although the technology to check for one's body burden -- called biomonitoring -- is nothing new, its use appears to both give revelations about the connection between people and the environment, and fuel debate about where that connection begins and ends.
In the study in which Brody participated, watchdog agencies the Environmental Working Group (EWG) and Commonweal commissioned the biomonitoring test to document the "pollution in people," according to Jane Houlihan, EWG's vice president of research.
The study, Houlihan says, reveals individuals may be even more vulnerable to toxicants than previously thought. "It's even likely that there's an even higher burden of disease from our exposures to different chemicals because we are exposed to so many simultaneously," she says.
Yet the link between the presence of chemicals in human blood and evidence of disease is not always solid. And if a link exists, there is often heated discussion over what level of exposure crosses the line into danger.
While the jury is still out, many health professionals suggest ways people can reduce their contact with contaminants, but even that topic inspires passionate dialogue.
"What can I do to protect my health?" ponders Brody. "Going through this biomonitoring made me feel like for this question, there are very few 'I' answers. There are only 'we' answers."
For that matter, answers seem to coexist with questions when it comes to discussions about body burden, disease, and preventing contamination. The overriding question here may, indeed, be, "What isn't in question?"
Chemical Exposure = Danger?
If we all remember our periodic table of the elements from high school science, chemical compounds are everywhere in the environment, and some of it can be found within ourselves -- for instance, oxygen.
What could make a chemical harmful is the amount of it that gets inside the body. "If there's a chemical out in the environment that's stuck to a piece of clay, but it never leaves that piece of clay, and it never gets inside your body, it never can hurt you," explains James Pirkle, MD, PhD, deputy director for science at the CDC's environmental health lab.
Some elements have been proved to be health hazards, says Pirkle, pointing to the established connection between lead and neurological disease, and cigarette smoke and cancer.
Yet there are many more mysterious compounds, says Shelley Hearne, DrPh, executive director of Trust for America's Health (TFAH), a nonprofit organization advocating for disease prevention.
"The majority of chemicals that we routinely use in this country have not been adequately tested for their effects on humans," says Hearne, calling for the government to do standard toxicological testing on substances in the market.
The CDC routinely evaluates compounds it suspects may cause health hazards. In fact, the agency is currently evaluating a set of manmade chemical called phthalates, which are often used in some food packaging, toys, automobile plastics, and cosmetic products such as soap, shampoo, nail products, deodorants, and lotions.
Animal studies show very high levels of some phthalates can cause birth defects in the male reproductive system, including undescended testicles, absent testicles, and a physical defect of the penis. Researchers are still trying to figure out the effects of phthalates on humans and what levels of it are safe.
Hearne argues that synthetic chemicals don't belong inside the human body and it is only common sense to conclude that they're not good for people. She says, "If I find out that I've got levels of a substance -- while we're not sure what level is bad for you -- but we do have indications that, one, this isn't naturally occurring, and, two, that at higher levels, it's a known toxin, I don't want it there."
Vern L. Schramm, PhD, chairman of the biochemistry section of the American Chemical Society, says it's important to keep things in perspective. "There are more toxins in the human body that are naturally occurring than those that are manmade," he says, citing the following examples: Most of the mercury in the fish we eat comes from rock sediments in the ocean, much of the arsenic in water leaks from rocks in aquifers, and dioxin is simply a byproduct of flame and cooking.
Even with all the natural and artificial chemicals in the environment, Schramm says the human body is usually well equipped to deal with a small amount of toxins.
Additionally, he says there is value to some manmade compounds. Babies who come in contact with fire-resistant clothes, for example, may have some flame retardant compounds in their system, but such garments save lives, says Schramm. Fewer kids reportedly die of burns because of flame-resistant wear.
Regardless of reassurances from experts that most everyday chemicals are safe, there are people who might worry that they may be wrong. For those individuals, Houlihan offers the following advice:
Brody also encourages people to get involved in advocating for less pollution. "What can we do to change policies so that we're protected?" she asks.
Groups like EWG and TFAH ask those same questions and press the government for more research on the effects of compounds on health.
The EWG, in particular, urges authorities to look into the cumulative effects of coexisting substances, as opposed to just the impact of one chemical.
Houlihan says there's growing evidence that otherwise safe doses of chemicals, when put together, can cause harm.
The CDC regularly assesses the chemical exposure level of the U.S. population through biomonitoring tests and comes out with its findings every two years. In the last report, scientists checked for 116 different environmental chemicals in the blood and urine of some 2,500 people.
The next CDC report is expected in 2005.
Published Feb. 17, 2004.
SOURCES: Charlotte Brody, executive director, Health Care Without Harm. Jane Houlihan, vice president of research, the Environmental Working Group (EWG). James Pirkle, MD, PhD, deputy director for science, CDC's environmental health lab. Shelley Hearne, DrPh, executive director, Trust for America's Health (TFAH). Vern L. Schramm, PhD, chairman of the biochemistry section, the American Chemical Society. CDC. National Report on Human Exposure to Environmental Chemicals, January 2003, CDC. Body Burden: The Pollution in People, January 2003.
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