What Is Indoor Air Pollution? – Definition, Sources & Effects – Video & Lesson Transcript | Study.com

Consider this: The average American spends about 90% of their lives indoors. Put this with what you now know about how polluted indoor air can be and that creates a dangerous situation! For developed nations, such as the U.S., the two most dangerous indoor air pollutants are tobacco smoke and radon.

Even if you are not a smoker, secondhand smoke can cause many of the same health problems as directly inhaling from cigarettes – things like lung cancer, emphysema, asthma and heart disease. Even if inhaling secondhand, you are still taking in over 4,000 chemicals, a large number of which are carcinogens, or cancer-causing chemicals.

Radon gas is also harmful indoors, and it is the second-leading cause of lung cancer in the U.S. (tobacco smoke is the first). Radon gas is a radioactive gas that comes from the natural breakdown of uranium in soil, rock and water. When the uranium breaks down, the radon gas seeps up and can get into buildings. Radon is especially dangerous because it is both colorless and odorless, which makes it impossible to detect without special testing equipment.

In addition to tobacco and radon, volatile organic compounds (or VOCs) create a variety of pollutants in indoor air. VOCs are carbon-containing compounds that are released by pretty much anything you can imagine – perfume, paint, plastic, household cleaners, adhesives, furniture, carpet, paper…even that nice ‘new car smell’ is really just the smell of toxic chemicals being released!