It comes from our furnaces, bathrooms, even man's best friend. Indoor air pollution is all around us.. and it's making us sick.
"Now that we're getting into the winter season and people are closing up their environments, people usually spend about 65% of their time indoors," said Kathy Sullivan, senior director of the Illinois Lung Association.
One of the most common indoor pollutants is mold. It grows wherever there's moisture... bathtubs, basements, you name it.
"Mold can cause a very serious reaction. Either it can cause an asthma attack or some sort of respiratory distress," Sullivan said.
One dangerous gas leaks into our basement walls and into our homes. Radon is a naturally occurring substance but it's the second leading cause of lung cancer.
"It's quite a serious matter but there are ways to deal with it, professional forms, if you have a radon problem will come and vent it out if your basement," Sullivan said.
Homes built in the late 1970's and 80's tend to be breeding grounds for air pollution. These homes were built air tight... So bad air can't get out, and fresh air can't get in.
"When you throw that out of balance you're going to have problems like bad air flow and moisture accumulation and then you're going to get into the molds and other factors that make a bad indoor environment."
Sullivan suggests replacing furnace filters and pin pointing the sources of air pollution in our homes... Then get rid of it.
"Do some basic experimenting with exposure. See if by cleaning up a particular area or ripping out a carpet in a bedroom that might help alleviate the situation or you can get professional help."
And if you're not sure it's pollution that's making you sick, take a walk outside. If you feel better, you've got some cleaning to do.
To learn about other sources of indoor air pollution and how to get rid of it, log on http://www.lungusa.org/site/apps/lk/links.aspx?c=dvLUK9O0E&b=36056&