If you think avoiding polluted air from smog and smokestacks is as simple as staying inside, think again. The Environmental Protection Agency (EPA) rates indoor air quality as the fourth-greatest threat to American health.
Indoor air is susceptible to the same pollutants as outdoor air, plus second-hand smoke, pet dander, mold, and dust mites, making it two to seven times -- and sometimes up to 100 times -- worse than outdoor air.
"In buildings, houses, and schools without proper ventilation, pollution can build up," says Kristy Miller, a public affairs officer for the EPA. "It's like a holding tank."
Since Americans spend 90 percent of their time inside, poor indoor air is now being blamed for a variety of respiratory problems, especially in children. Asthma and allergy attacks can result, as well as "sick building syndrome" -- a series of symptoms including headaches, dizziness, sinus congestion, itchy or watery eyes, scratchy throat, nausea, lethargy, and inability to concentrate.
Many studies link asthma and other respiratory illnesses to air pollution. The percentage of asthma-related hospital visits has increased 75 percent nationwide since 1980, leading doctors and researchers to look to the stale, dirty air that Americans breathe. Since many dirty industries and power plants are located in low-income neighborhoods, African Americans have been hit especially hard by the disease.
Unlike clean outdoor air or water, good indoor air is one of the few environmental risk factors individuals can control at home without spending a lot of money. The EPA Web site (www.epa.gov) says intensive cleaning, banning indoor smoking, keeping pets outside, making sure dryers and furnaces are vented properly, and reducing indoor humidity will reduce many of the airborne particles that can bring on asthma and allergies. Dust mites and mold grow in humid climates, but by keeping the thermostat below 70 and opening the windows occasionally their growth can be checked.
Miller says the surgeon general also recommends all American houses be tested for radon, a cancer-causing gas that is a product of the decay of naturally occuring uranium in the earth's crust. A test kit can be purchased for less than $20, she says. If radon is detected, the problem can be easily fixed. Asbestos, a cancer-causing insulator, is harder to get rid of but is a serious problem in many older buildings.
Exacerbating the air problem is the fact that most office buildings and houses built since 1980 are airtight to reduce heating and cooling costs. Not only is the same air constantly circulated, but dust mites and molds can easily thrive in the heating and cooling ducts.
While reducing indoor air threats in a house is fairly simple, making sure office buildings are safe is more difficult. Not only are there thousands of feet of air ducts where dust and mold can build up, but building managers rarely take the steps necessary to avoid a problem.
The EPA Web site recommends that office workers report all air-related symptoms to management and encourage them to have their building inspected if symptoms persist. Risk-assessment materials and inspections, if needed, can be found by calling the National Institute for Occupational Safety and Health (800-35NIOSH).
Indoor air in buildings can be improved by replacing standard cardboard filters with electrostatic filters which also increase the life of the heating and cooling equipment. Traditional filters trap only 15 percent of airborne particles and are ineffective for pollen, microorganisms, and smoke. Although more expensive, electrostatic filters trap 95 percent of all airborne pollutants by charging the particles and catching them magnetically.
Allergy and immunology specialist Dr. J.D. Fleenor of the University of Tennessee-Memphis sees the effects of bad air every day. The same children keep coming back to the intensive care unit with asthma so bad their parents fear for their children's lives, he says. When treatment doesn't help, Fleenor sometimes tests their everyday environment for allergens.
"We often find that they are being exposed to what they are allergic to every day," Fleenor says. "Sometimes we try to get the parents to move or change jobs to protect their children."
Electrostatic filters work for some people, Fleenor says, but studies have found the best way to decrease symptoms in the home is to cover pillows and bed linens when they are not being used in order to keep allergens from settling there.
One 5-year-old child described his difficulty breathing as being like "a fish without any water." Children's lungs are more sensitive because they are growing, so bad air affects children worse than adults. In the last 15 years, there has been a 160 percent rise in diagnosed cases of asthma among children, according to EPA studies.
A federal General Accounting Office study found that half of our nation's schools have poor ventilation and pollution. The same techniques used to reduce airborne particles in homes and offices can be used in schools. Additional resources such as checklists, facts sheets, and teaching tools for schools, can be obtained from the EPA Web site.
The connection between indoor air quality and respiratory ailments such as asthma was studied by the National Academy of Sciences in a study released last year.
"The prevalence of asthma continues to rise dramatically in this country and the reason why is a mystery," says the study's committee chair, Richard B. Johnston Jr., a professor in the department of pediatrics at the University of Colorado School of Medicine. "People spend most of their time inside, and it's vital that we understand how the indoor environment may contribute to the disease."
The study found that dust mites can lead to asthma in those predisposed to the disease, and that allergens from cockroaches and pets can worsen the condition. Second-hand smoke was also linked to worsening of the condition in preschoolers, but the results were inconclusive for older children.
While the direct cause of asthma remains unclear, Miller emphasizes simple steps can be taken so asthmatics and everyone else can breathe just a little bit easier.
You can e-mail Andrew Wilkins at firstname.lastname@example.org.