Ask people about the biggest threats to their health, and indoor air quality likely won’t make the list. In fact, according to Consumer Reports National Research Center, only 9 percent of Americans consider indoor air quality a threat to their health. This same survey found that 70 percent of Americans aren’t concerned at all about their indoor air quality. What many people don’t consider, however, is that many of the things that they do, or don’t do can add to a potentially dangerous combination of airborne contaminants in their homes that can trigger or worsen asthma, allergies and contribute to the risk of other health conditions.

What Are the Risks?

The risks associated with poor indoor air quality can vary greatly, depending on the kind of pollutant you have in your home. The following are some common invisible contaminants that may affect your indoor air quality:

Invisible Killers: Carbon Monoxide and Radon

Consumer Reports explains that carbon monoxide and radon are colorless, odorless and deadly. Carbon monoxide can accumulate in a home because of faulty gas ranges, cooktops and furnaces, as well as wood, kerosene and propane heaters. Those who use gas generators are also at risk for carbon monoxide contamination if used in a garage or near open windows.

Radon is one of the leading causes of lung cancer among non-smokers. This gas escapes from rocks, soil or water beneath your house and can collect at unsafe levels. And because radon levels can vary from house to house, the only way to recognize a problem is to test your individual property.