Why is radon higher inside a home than outside?

This is one of the most common questions we get, along with its follow-on: why am I just now hearing about radon (ie, is this some sort of modern scam or what)?

The answers to both questions are pretty straightforward. Radon seeps up through the soil in its natural life cycle. It is a gas made of tiny particles, and as it decays it moves up and into the atmosphere. Our homes have a negative pressure caused by our heating and air conditioning systems. Think of it as a very low pressure vacuum cleaner, which leads to a suction that gathers more of the earth gases into the home than outside of the home. As I mentioned, it is a very, very small pressure difference caused by the heating and cooling system, but it nevertheless is a difference, and that means more earth gases (and hence radon particles) enter your home.

The other side of the equation is the exhaust. Homes being heated or cooled are typically shut (ie, no open windows), so they don’t “exhale” the gases as they would if the windows were open. This also causes the radon to remain within the home.

The answer to the second question is related to this phenomenon. One of the reasons radon levels tend to be more elevated these days is that our homes are better sealed for energy efficiency, therefore reducing the amount of air transfer that escapes the home.

Another very significant fact is that the dangers of radon were not known until the latter part of the 20th century, and they began with a study of miners who had a high incidence of lung cancer. Research led to the findings and understandings we now have of how radon affects our lungs, and through the years the data has led to greater understandings of how we can protect ourselves from the harmful effects.

By the way, we are always happy to talk to you about radon or any other home concerns you may have, here in Louisville, KY or where you live. Feel free to visit us at www.HomeTeam-Louisville.com, or call us at 502-357-0813.

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Associations & Memberships:

  • Certified Radon Professional
  • International Association of Certified Indoor Air Consultants (IAC2)
  • Kentucky Home Inspector L#3024
  • Kentucky Home Inspector #3192
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