After radon was recognized as the culprit causing high rates of lung cancer in miners, most folks in the construction, realty, and engineering industries came to realize radon gas-a radioactive substance–is not our friend when it comes to indoor living. Still, the grim stats on radon-induced lung cancer deaths and the public’s poor understanding of the problem recently left our Indoor Air Quality experts at BPE, quite frankly, exasperated.

Clearly, the CDC, EPA, and WHO have not kept radon risk statistics a secret; the information is free and available to all. Organizations such as are not shy about pointing out that, “Many families are living in homes with radiation levels that exceed the EPA’s allowable limits for Nuclear Power Facilities and are unknowingly being exposed to higher radiation doses than hundreds of chest x-rays every year.” So where is the public outcry? Are we treating radon test scores like creepy Uncle Dave–everyone has one, but we’d rather not talk about it? Or is the message that radon-induced lung cancer deaths per year in the United States average the population of a small city (approx. 21,000) simply not getting across?

Here’s the Message: There is no risk-free level of radon exposure and eliminating it completely from our lives is impossible. Still, the EPA recommends that radon-reduction actions be taken when test levels come out at 4.0 pCi/L (picocuries per liter – a unit for measuring radioactive concentrations) or higher. WHO goes lower, recommending action at 2.7 pCi/L. Even so, approximately 6 million (1 in fifteen) homes in the United States have radon levels that exceed the EPA’s recommendation. That’s a hefty number of people exposed to low to moderate concentrations of radon that are the number one cause of lung cancers in non-smokers. In smokers, radon comes in second place only to smoking. Now consider that even 4.0 pCi/L readings will deliver lung cancer to 7 out of 1,000 non-smokers and 62 out of 1,000 smokers. A 2.0 PCi/L reading is bad news for 4 out of  1,000 non-smokers and 32 out of 1,000 smokers.


Suddenly, staying home (as a smoker with a home radon reading of 4.0 pCi/L) is five times riskier than dying in a car crash. And speaking of staying home, when it comes to home-related deaths, radon tops the list:


Are we trying to scare you? In a word, yes.

The lung cancer deaths of approximately 21,000 people a year look like …

  • a Chernobyl disaster every two months (based on WHO’s projected 4,000 Chernobyl deaths).
  • the number of people buried in ash when Mount Vesuvius erupted and covered Pompeii.
  • about one-third the number of U.S. military deaths in Vietnam.
  • 1,260,000 Lego bricks–when you consider there are 60 Lego bricks available for every person on the planet. (At BPE, we’re nothing if not informative!)

More sobering, implementing radon mitigation techniques-particularly balanced ventilation-can reduce radon risks proportionately. Lack of information and/or urgency is no reason for so many people to die of radon-induced lung cancer each year.

So, What Exactly is it? Radon is the naturally-occurring radioactive gas that comes from decaying uranium. It leaks from rocks and soils and is rife with heavy metallic decay products, specifically polonium, lead, and bismuth. Although we cannot do much about the far lower radon levels we encounter outdoors (typically 0.4 pCi/L), the concentrations indoors are

of far greater concern. Radon builds up in enclosed places such as basements and mines by seeping from the soil through gaps around pipes, sumps, drains, and porous cement foundations as well as inevitable cracks. In some cases, radon has been found mixed into the cement!

Indoor radon levels vary from home to home, season to season, day to day, and even hour to hour. They depend on the amount of uranium in the area, the routes available in the home that cater to seepage, the tightness of the building, your area of the country, and ventilation (the rate of exchange between indoor and outdoor air). Due to proximity to the ground, basements and the lower floors of a building generally hold higher radon concentrations.

Take Action: The first step in mitigating possible radon issues is much like monitoring your cholesterol: Know your numbers! Home inspectors may tell you your radon levels are in the safety zone, but you know better now. Pick up an electronic radon detector and use it at the lowest level of your home first, then take readings on the floors above. We used an Airthings Home 223 Radon Detector(under $200) for a case study on mitigating radon in a 7,452-sqft home. The study, which we will present in next week’s Part 2 of our Silent, Deadly … Insidious series, will demonstrate how balanced ventilation can aid in the fight to lower radon levels.

In the meantime, we are looking for feedback on your experiences with radon issues. Please drop us an email at, tweet, visit our Facebook or LinkedIn page and answer the following: Were you fully aware of the dangers of radon before reading this article? Do you know your radon level numbers? If so, what are they and do you feel you need to do something about them?

We hope this series will be food for thought in bringing more attention to the very real and unnecessary deaths caused by indoor radon exposure. The fact is, if you live above the Mason Dixon line, you have a radon issue. Good ventilation practices are one way of taking control of home radon levels.