weather tight homes trap airborne particles inside where
everyday household contaminants can become increasingly
concentrated. The result: indoor air can be up to five times
more polluted than the air outdoors.
I've never heard anything about indoor air quality before.
The majority of people are not aware of the poor quality of
some indoor air. Americans spend approximately 90% of their
time indoors, either at home or at their workplace, where they
can be exposed to very high levels of airborne particles. In
fact, the EPA ranks indoor air pollution among the top five
environmental risks to public health. Furthermore, according
to the EPA, levels of many airborne pollutants may be 25-100
times higher than outdoors. Most of the airborne particles
cannot even be seen.