You've probably heard that the sweet air of hearth and home isn't all it's cracked up to be. Recent Environmental Protection Agency studies found that, on average, the air inside a house is three to seven times as polluted as the air outside.
Just the sort of news that makes us stop reading the newspaper. So wouldn't it be great if you could just plug in a little machine that would filter all the pollution out of your air?
A lot of people think that's what they're getting when they buy an air cleaner. But before you plunk down several hundred dollars for one, take a look at what you can expect an air cleaner to realistically do for you.
There are basically two kinds of air pollutants: particles and gases.
Particles are tiny solid or liquid bits light enough to float in the air. Some of the particles are so small that you can breathe them deep into your lungs. These are called respirable-size particles, or RSP, and they may cause acute or chronic health effects. RSP include those from cigarette smoke, fireplaces and wood-burning stoves, viruses, some molds and bacteria.
Slightly larger particles, such as pollen, dander and house dust allergens, don't penetrate your lungs as deeply, but they can cause debilitating allergic responses.
Gaseous pollutants you may be breathing at home are mostly combustion gases, such as those from cigarette smoke and unvented heaters and gas stoves, and volatile organic compounds (VOCs) from cigarette smoke, building materials, paints, adhesives, solvents, cleaners, hair gel, perfume, craft materials and pesticides -- to name just a few!
Health effects from these gases depend on how long you are exposed to how much of them, and how sensitive you are to them. They range, however, from itchy eyes to allergic reactions to nasty things like damaged immune systems and cancer.
According to indoor air experts, there are three ways to rid your home of these pollutants. The best way is to get rid of the sources of the pollutants. Check the resources below for help, but here are a few examples: Replace your kerosene heater with a non-polluting or vented one. Buy mattress and pillow covers that seal off dust mites. Don't use pesticides indoors. Don't smoke indoors.
The second best way to clean up your indoor air is to increase ventilation. Install a fan over your gas stove and in your bathroom (to expel moisture) and use it. Leave windows open when you can. If your house is very airtight, install an air-to-air heat exchanger.
Now, if you have done everything you can to get rid of the sources of pollution, and to increase ventilation at home, and you are still experiencing problems from your indoor air, then an air cleaner may be a help.
The pollutants air cleaners tackle best are the RSPs, the ones light enough to stay suspended in the air for long periods of time. The problem with particles is that your air cleaner can clean them only as long as they are floating.
Dander, for example, a fairly heavy particle, will settle onto the sofa. When your asthmatic child sits on the sofa, she'll stir up a littlecloud of dander and breathe it in before the air cleaner gets to it. That's why even the best air cleaner can do only a partial job. However, if your allergies are bad, even a partial job can give you some relief.
The jury is still out on air cleaners that profess to remove gases from your indoor air.
To remove gas, an air cleaner must have a special gas-absorbing material, such as activated carbon or alumina. However, experts aren't sure these materials can be effective enough for any length of time. One Environmental Protection Agency study showed that a cleaner with an activated carbon filter was only 50 percent effective at removing VOCs after a mere 15 percent of the manufacturer's recommended filter lifetime. Other studies have shown that the absorbent materials can slowly give you the gases back. Currently, experts at the EPA and the American Lung Association don't recommend air cleaners for gas removal.
If, after reading this, you think you might benefit from an air cleaner, do your homework before opening your wallet. The EPA offers a free booklet called "Residential Air-cleaning Devices, A Summary of Available Information." Write EPA, Indoor Air jTC Division, Washington,D.C. 20460. (Ask them for their guide to indoor air pollution, "The Inside Story," while you're at it.) Then go to the library and look up the February 1989 issue of Consumer Reports magazine, which contains a review of air cleaners.
One last thing. Some air cleaners purport to clean your air by emitting ozone. Here is what Indoor Air Quality Update concludes about that: "Levels of ozone required to kill microorganisms and oxidize odorous compounds are toxic to human beings." Don't buy an air cleaner that makes ozone.
For more information on indoor air pollution, call your local branch of the American Lung Association and ask for copies of their indoor air pollution brochures.
(Feeling environmentally incorrect? Write a letter to Ms. Household Environmentalist and send it to P.O. Box 121, 1463 E. Republican St., Seattle, Wash. 98112.)