You've seen the pictures of Los Angeles from afar: Nubby skyscrapers rise up and disappear into a brown smudge that covers the city like a lid. Perhaps you've been there or visited a city like it where, if you breathe deeply, your lungs catch and send you into coughing spasms. How relieved you are when you retreat to your home where, of course, the air quality is much better.
Or is it?
Every 24 hours, you inhale 10,000 liters of air, much of it in the sanctuary of your own home. What you might not know, however, is that some homes' air quality has been shown to be two to five times worse than the outside air. Why? And what can you do to improve your home's air quality?
In recent years, Americans have grown more concerned with energy conservation, which has added to the problem of poor indoor air quality. Our energy-efficient homes have become tight, sealed-off havens that increase the amount of potentially harmful gases in them. Add the harmful household chemical compounds that have "enriched" our lives for several decades, and you have a not-so-savory recipe for low-level toxins that could lead to long-term damage to your health.
Upwards of 70,000 synthetic chemicals are in use in the United States today; many of them can be found inside your home. They keep your carpets from squashing, staining and fading; they hold your expensive kitchen cabinets  together; they soften vinyl; they ward off mold. But while they make your life attractive and fungus-free, many of these chemicals contain volatile organic compounds (VOCs) that "outgas," or vaporize. They mix into the air in your home and form an unpleasant and even dangerous "chemical soup." The average American home has 50 to 300 VOCs and also contains molds, dust and dust mites, combustion by-products and pet allergens. Not the sort of air most of us would want to breathe.
Fortunately, there are resources available to those facing the problem of scary air in their homes. One such source, Building a Healthier Home, provides a road map for people in every budget range to follow on their paths to healthier homes. The author, environmental engineer Dan Morris, explains the necessity of a planned approach to healthy home construction. Typically, those in construction use "what's out there"; in other words, if you're not involved in every step of the process, your home will be built out of readily available, low-cost materials that are easy to install -- materials that will profit your supplier and builder -- not you. So speak up! Get a guide like Morris' and educate yourself before you build.
Start at the foundation. Seal the concrete and isolate it from the main living space. Don't install carpet  directly on the concrete floor; you'll be asking for trouble in the form of mold and dust mites. Provide adequate light and ventilation.
Now for the floors. Remember, the glue that holds together those old standbys -- particleboard , plywood  and oriented strand board -- contains urea-formaldehyde, which has been found harmful even with low-level exposure. Choose instead flooring materials that have few or no toxic chemicals.
Before you lay down that plush carpet, examine its makeup. New carpet contains 60 to 200 chemicals that are designed to make the carpet manufacturers happy -- not you or your lungs. Although the heaviest levels of outgassing occur during the first few days after installation, those chemicals will continue to leach into your air for years. Consider covering your floor with something hard and smooth instead, like wood , marble , ceramic tile  or even linoleum.  If you're nothing without your carpeting, consider wool and low-pile coverings.
Your heating and cooling systems can be serious sources of pollution. If not properly filtered and maintained, they'll spread pet allergens, dust and unwanted moisture throughout your home. If funds allow, choose a system that controls fresh-air intake, humidity and circulation.
When it's time to color your home, learn the components and types of paints.  There are actual "levels" of safety assigned to paints; it's up to you to make an educated choice for you and your loved ones.
However daunting the task of healthy building may be, there is help out there. The added costs are not nearly as frightening as some may assume -- usually somewhere between five and ten percent -- besides, it's difficult to assign a monetary value to the health benefits you reap. And if your home is already built, don't worry. There are plenty of steps you can take to increase the air quality within.
Why not take a moment to walk through your house right now and, using the guidelines you've just learned, assess the elements that might be contributing to poor air quality?
Start in the bedroom, arguably the most important room to "fix." You and your loved ones spend a full third of your lives in the bedroom, so try to lessen the amount of VOCs and other irritants. For example, don't accept dry-cleaned clothing until they have been properly dried. If you use a humidifier , keep it clean and refill it daily with clean water. Consider removing the carpet in your bedroom, which harbors dust mites and their attendant allergens. Speaking of dust mites, the fewer soft, unprotected items in the bedroom (unprotected pillows, mattresses, curtains, chairs, etc.), the smaller the population of dust mites.
How about your kitchen? Perhaps the worst culprit here is household cleaners. Open those windows when you clean! Before you purchase cabinets , ask the salesperson about formaldehyde content and release. Some types of pressed-wood products emit less formaldehyde than others. After installation, open the windows. Check your gas stove/range. Make sure they are properly vented and burning with a blue flame tip -- not yellow or orange. And remember: Never use your gas stove to heat your home.
Move on to your bathroom. Here, an exhaust fan will solve myriad problems. It will remove moisture, lessen odors without the use of air fresheners, and rid the room of gases from personal care products.
Down in the basement, moisture is a major culprit. A dehumidifier  is a good idea; remember to empty and clean the water tray often. For ground-moisture problems, clean and disinfect the basement floor drain regularly. Stored hobby products (paint, glue, etc.) should be sealed tightly in their containers. Cleanup duties should occur outside; if inside, open the windows or use an exhaust fan to clear the air of potentially dangerous vapors. And, of course, radon. Test your home for radon. Do-it-yourself kits are easy and inexpensive. For more information, contact your state radon office or call (800) SOS-RADON.
Don't forget your garage. Here, paint supplies, pesticides, herbicides and stored fuels (just to name a few) are probably present in significant numbers. Don't store any of these inside your home. Make sure their containers are well sealed. When appropriate and possible, use these products outdoors. The garage may be your car's home, but you should never idle the car in your garage. If your garage is attached to your home, it's a good idea to use weather stripping to keep the exhaust out of your home.
Last, rest assured: Your home will not look like a science experiment if you follow these guidelines. Those healthy elements will look good and, perhaps most importantly, they'll put your mind and your lungs at ease.
Photography by John Gregor/ColdSnap Photography
Sources: Home as an Oasis, by David Buscher, M.D.; You Are What You Breathe, by Dan Morris; literature from the American Lung Association; United States Environmental Protection Agency (Indoor Environments Division); Consumer Federation of America; and California Air and Industrial Hygiene Laboratory documentation.