By Christina Elston
"A baby crawling on the floor inhales the equivalent of four cigarettes a day, as a result of the outgassing of carpets, molds, mildew, fungi, dust mites, etc."
So claims the Web site of a company selling air purifiers. Similar messages seem to be all over the media these days. But before you hold your breath and rip out the rug, put things into perspective. Problems with our air can cause problems with our health, but carpets and dust probably aren't the biggest offenders.
The top three indoor air threats are carbon monoxide, radon and environmental tobacco smoke, says Janice Nolen, director of national policy for the American Lung Association. "Those have been documented beyond doubt to have a likelihood of causing premature death. They're often not the things people think about when they think about indoor air quality, but as problematic as dust mites are, the effects pale by comparison."
These days, families are concerned about all kinds of environmental toxins, but researchers and clean air experts say that in most cases there are very simple things you can do to clean the air your family breathes and ease your mind.
The Big Three, Plus One
1. Carbon monoxide is "probably the most immediately dangerous compound found in homes," says Bob Axelrad, a senior policy advisor for the Environmental Protection Agency's (EPA) Indoor Environment Division. "We still hear far too often about entire families dying because someone left a car running in an attached garage, or brought a wood-burning grill indoors." The colorless, odorless gas can also build up when gas stoves or dryers, or fireplaces, aren't adjusted or vented properly.
2. Environmental tobacco smoke, or secondhand smoke, is one of the most prevalent indoor air pollutants and is known to have a wide range of health effects, says Janice Kim, M.D., of the American Academy of Pediatrics Committee on Environmental Health. These include increased risk of sudden infant death syndrome (SIDS), bronchitis, pneumonia, asthma and fluid buildup in children's inner ears.
3. Radon, the leading cause of lung cancer among nonsmokers, is associated with 23,000 deaths in the United States each year and could be present in any home. Exposure is especially risky for kids who might be living in the house for 18 years. "Sometimes with lung cancer, the impact of what you've done shows up 20 years later," Nolen says.
4. Biological factors such as dust mites, pet dander and cockroaches are well-known asthma triggers, says Kim. Moisture helps these contaminants thrive, and also adds another: mold.
Volatile Organic Compounds
But what about that stuff that may be "outgassing" from your carpet or other products in your home? These are called "volatile organic compounds" (VOCs) and, according to the EPA, include a host of chemicals used in paints, solvents, wood preservatives, aerosol sprays, cleaning products, moth repellents, air fresheners, hobby supplies and dry-cleaned clothing.
Not much is known about the impact of exposure to VOCs at home, but major studies of occupational exposures do point to some potential health effects. Formaldehyde, one of the most studied VOCs, can "outgas" from pressed wood furniture and has been shown - at high levels - to cause cancer, according to Kim. Occupational exposures to benzene and ethylene, found in solvents, nail polish and dry-cleaning chemicals, have been shown to cause liver damage.
Some experts believe that the levels of VOCs in homes just aren't high enough to worry about. "We haven't found that many common consumer products have been related to major health outcomes or health risks," says Axelrad. But he notes that any product could pose a risk if used improperly. "The indoor environment does tend to trap any contaminants that are found there. If they say, 'Use proper ventilation,' they mean it."
Still, none of us is exposed to VOCs from just one source.
"It is difficult to tie observed health effects back to a particular product or ingredient because so many products are involved," says Philip Dickey, a staff scientist at the Washington Toxics Coalition, an environmental organization dedicated to educating the public about toxins in the environment. "But," he adds, "the scientific evidence is growing that the health risks from these materials are significant."
The Risks for Kids
The federal government has stepped up efforts to understand how VOCs and other pollutants might affect children, founding research centers such as the Columbia Center for Children's Environmental Health in New York.
"The interest and the data are growing," says the center's director, Frederica Perera, Ph.D. "But this is still an area that needs more attention, both in terms of research and in terms of action in response to the research."
Experts do agree that children are generally at greater risk than adults from toxic exposures of any sort. Their higher metabolisms mean that they eat more, drink more and breathe more air - per pound of body weight - than do adults, so contaminants enter their bodies at higher levels.
"The very young child is actually taking in more of certain pollutants," explains Perera. In addition, 80 percent of a child's lungs develop after birth, and continue to develop until the child reaches adulthood.
A child's developing immune system might also be less resistant to the impact of toxic exposures than an adult's, according to Cornell University researcher and immunotoxicologist Rod Dietert, Ph.D. At the fetal stage, a baby's immune system is partially suppressed to allow mother and baby to co-exist safely, he says.
That means that severe and permanent changes could be induced in the immune system by exposures to environmental toxins during development, Dietert says. "These are not necessarily the kinds of changes that might produce immediate newborn death," he explains, but they could be responsible for recent sharp increases in chronic health problems, such as asthma, multiple allergic reactions, lupus and rheumatoid arthritis.
Christina Elston is the contributing health editor for United Parenting Publications.
Janice Kim, M.D., of the American Academy of Pediatrics, warns against air cleaners that generate ozone as part of the cleaning process (usually specified in the product description). "They can emit levels of ozone into the home that are as high as extremely smoggy days in Los Angeles," she says.
- Christina Elston
American Lung Association Health House - www.healthhouse.org - Offers tips on safe home building, remodeling and maintenance, with clean indoor air in mind.
Association of Home Appliance Manufacturers - www.aham.org - Has information on indoor air cleaners.
Environmental Protection Agency - www.epa.gov/iaq/pubs/ozonegen.html - Includes details on the hazards of ozone-generating air cleaners.
National Institutes of Health Household Products Database - http://householdproducts.nlm.nih.gov - Provides information on particular chemicals.
Washington Toxics Coalition - www.watoxics.org - Offers information about alternative household products.