While most of us are aware of the hazardous air quality that can exist outside our homes, many of us would be surprised to learn that, according to Environmental Protection Agency research, the air inside the typical home contains at least two to five times more pollutants than the air outside. In fact, the EPA considers indoor air pollution to be one of the top five environmental health risks.

Poor indoor air quality is usually the result of some combination of the following five factors:

1. The large number of chemical substances we use to clean our home and ourselves.
2. The chemically treated and synthetic materials used to build and furnish our homes.
3. Inadequate fresh air—the con of having tightly sealed, highly insulated homes.
4. Improperly maintained or vented combustion equipment (gas stoves, furnaces, hot water heaters).
5. A concentration of outdoor air pollutants, especially in urban areas.

There are a number of questions you can ask in order to help yourself become more aware of the quality of the indoor air in your home or workplace. Here’s a short list to start:

1. When I come inside after being in fresh air, what do I smell? Are the odors unusual or do they linger?
2. Does the air in my home regularly feel stuffy or stale?
3. Does anyone smoke in my home, including regular guests?
4. Does anyone in my home suffer frequent allergies, colds, respiratory problems or burning eyes?
5. Are mold and mildew present in any room?
6. Do I use kerosene or other non-electric space heaters?
7. Does my home contain any new plywood?
8. Do I use any synthetic personal care products?
9. Do I use synthetic chemical household cleaners?
10. Are my furnishings made of synthetic foam?

Before you rush out to buy an expensive air filter, there are a couple of cost-free steps you can take now to improve the air quality inside your home.

First, try to eliminate any potential indoor pollutants at the source (think commercial household cleaners, personal care products, synthetic furnishings). This will rid your home of a certain percentage of pollution permanently and free you from worrying and monitoring those items.

Secondly, ventilate your home whenever possible in order to dilute and replace the air within your home. While outside air contains pollutants of its own (especially in urbanized areas), any amount of ventilation is usually helpful.