For the past 30 years, Americans have been bombarded with warnings about the ill effects of outdoor air pollution.
Unfortunately, what’s inside our homes can be as bad for us, if not worse, than what’s outside.
“Most people don’t think about indoor air pollution,” says Elissa Feldman, an associate director of the Indoor Environments Division for the Environmental Protection Agency. “Our focus is instead on problems with the outdoors. In fact, people are told to go indoors when the air quality is bad.”
But there’s a growing amount of data that shows we need to think harder about indoor air quality, says Feldman, especially considering that most people spend 90 percent of their time indoors.
EPA studies have shown, shown, for example, that indoor air levels of many pollutants can be two to five times higher than outdoor levels.
And last year, the Presidential/Congressional Commission on Risk Assessment and Risk Management stated that one of the bigger risks to human health is indoor air pollution.
“They also reported that it’s mostly unregulated and deserves immediate attention by Congress and the administration,” adds Feldman.
“Indoor air quality is finally starting to be thought about,” says Alex Wilson, editor and publisher of Environmental Building News. “It’s becoming the largest driver of concerns in the construction of houses today.”
There are several causes and sources for indoor air pollution, say the experts.
“One the problems is that we’re building tighter houses to improve the energy performance of those homes,” says Wilson. “That tightening elevates the effects of indoor pollution and can dramatically affect air quality.”
In addition, we’re also packing our home with more “synthetic things,” says Wilson. “Building materials, upholstery, furnishings, carpeting and general consumer products can be made from petroleum and contain a wide range of chemicals, some of which can (release gas) into the air in a home.”
There are a few telltale signs of potential air quality problems in your home: stuffy, stale air; excess condensation in windows; mold growth; or cooking and other odors that linger for hours.
And curing those indoor air woes is more complicated than purchasing an electronic air cleaner, notes Feldman.
“A lot of times people are wasting their money with such devices,” she says. “Dust and pollen are heavy enough to settle out of the air and into carpets and furniture so small air cleaners are ineffective.
“Instead, you need to figure out what problems are contributing to poor air quality in your home and address those individually,” Feldman says.
For example, better ventilation can help, according to the experts. Keep in mind that most heating and air-conditioning systems don’t draw in outdoor air. Weather permitting, open windows to bring in fresh air.
There are numerous other steps you can take. What follows is a breakdown of indoor pollution sources and what a homeowner can typically do to lessen their effect:
– Radon. This is a natural gas that comes from the breakdown of uranium in the soil beneath a home. It seeps into a house through cracks in basement floors and walls, floor drains, sump pump pits and dirt floors. “Once the radon is sucked into your home, it gets trapped,” says Feldman.
Found in homes old and new, radon can be deadly. EPA research shows that radon is responsible for 15,000 lung cancer deaths per year.
The first step in eradicating radon is to have your home checked for radon levels. A number of kits can be purchased to measure radon levels. Most involve exposing a small canister in your lowest living level of your home for a number of months. The canister is then mailed to a testing laboratory, which measures it for radon and sends the results to your home.
If the radon level is high–the EPA says a rayting of 4 picocuries per liter is a concern–there are a number of recommended steps, says Feldman.
The first is to seal your basement by patching cracks and holes in the floor and walls. A new sump pump pit cover should also help.
Another possible option is “a sub-slab depressurization.” In this procedure, a hole is drilled into the basement floor and then piping and a fan are used to suck any radon gas from under the house up and out into the atmosphere.
– Moisture. One of the most common and troublesome problems plaguing indoor air quality is excess moisture, says Wilson.
“High moisture can create conditions for mold, fungi and biological contaminants to grow and thrive,” says Wilson. “And products such as wall-to-wall carpeting provide the environment in which biological contaminants such as mold can prosper.”
Water-damaged building materials such as Sheetrock, carpeting and wood also provide nutrients that mold likes to eat.
“The problem with mold is that many people are allergic to it,” says Feldman. “It’s a key trigger for asthma. And it can also create a weakness in the structure of a home.”
The solution here is to examine a home for moisture problems and solve them.
In addition, run bathroom and kitchen ventilation fans to expel moisture while taking showers or cooking. Also, don’t store firewood inside a home. It can release moisture into the air.
Finally, make sure water–rainwater–isn’t getting into your home. Correct seepage problems in basements and crawl spaces and repair any leaks in the roof or siding. Fix gutters that may be contributing to the problem.
If you have high humidity problems, consider buying a dehumidifier. However, it needs to be well-maintained and kept clean or it can cause more health problems than it alleviates, says Feldman.
If you find visible mold, use a diluted bleach solution to clean it. “If you can’t clean a carpet or piece of furniture that has been water damaged within 24 hours, consider replacing it,” says Feldman.
– Carbon monoxide. This odorless, colorless gas hinders the delivery of oxygen through the body. Low concentrations can cause weakness, nausea, headaches and dizziness. Higher concentrations can result in unconsciousness and death.
Carbon monoxide buildups occur when emissions are not properly vented from a home. They can come from a blocked or leaking chimney, or from a faulty flue pipe.
Carbon monoxide poisoning causes some 1,000 accidental deaths per year, according to EPA data, with 800 of those deaths caused by cars running in attached garages. “Someone forgets to turn off the car and the exhaust not only kills someone in the car but people in the home,” says Feldman.
The other 200 deaths result from combustion appliances–furnaces, boilers and water heaters–that are not properly vented.
To prevent carbon monoxide from seeping into your house from an attached garage, make sure it is sealed off. Proper weather stripping on the access door between house and garage will not only prevent the carbon monoxide seepage but also help reduce cold air infiltration.
It’s also important to install carbon monoxide detectors in your home. They are now the law in Chicago.
Finally, have combustion appliances checked yearly to make sure they are operating properly and that there are no problems with blocked flues.
Tobacco smoke is another concern. What’s commonly known as “second-hand smoke” can also be deadly. EPA estimates that environmental tobacco smoke results in 3,000 lung cancer deaths of nonsmokers each year.
“It also results in respiratory infections and middle ear infections and can make asthma a lot worse,” says Feldman.
The simple solution here is to not allow smokers to smoke inside a home. If they insist on smoking indoors, increase the ventilation.
– Household chemicals. “There’s a class of over-the-counter household products which contain chemicals that can be unhealthy–ranging from pesticides to cleaners,” says Feldman.
“The ill effects of these chemicals can include eye, nose and throat irritations to dizziness to cancer, depending on the product and the exposure to the product.”
The solution is to simply be careful with such products, always using them in well-ventilated areas. Also, closely read the labels.
“If the product says spray for cockroaches every month, don’t use it every week,” says Feldman. “Or use baits versus aerosol products. Better still, address the problem by making sure pests are denied food and water sources.”
In addition, choose products that have lower volatile organic compounds (VOCs), says Wilson. “Newer water-based paints and finishes usually have lower VOCs than solvent or oil-based products,” he says.
There are also “natural” cleaners–such as citrus-based solvents–that can be substituted for chemical products. “But you may be sensitive to those products as well,” says Wilson.
For more information on indoor air quality, visit the EPA’s Web site at http://www.epa.gov/iaq/ or call their information clearinghouse at 800-438-4318.
