January 26th, 2021

Radon Gas: An Invisible Threat in Our Homes

Why Is Radon Dangerous?

 by Christopher Bloom and Jo Miller

This is the first installment in a three-part blog series. Part two is available here.

January is National Radon Action Month.

Did you know that radon is the leading cause of lung cancer among nonsmokers and that exposure to radon gas causes more than 20,000 deaths annually? The good news is that exposure to radon is preventable.

In this three-part blog series, we’re going to share:

1. The facts about radon,
2. How to determine if there is radon in your home or other building, and
3. Steps to fix the problem to protect yourself and your family.

What Is Radon?

Radon is an odorless, colorless, and tasteless gas that can be found virtually everywhere, though its concentration can vary depending on several factors. Radon forms when uranium and thorium, radioactive elements often found in rock formations, break down into radium; the radium in turn decays into radon, which rises out of the soil into the atmosphere. Examples of rocks that may contain uranium include granite, phosphate, pitchblende, and shale.

Where Is Radon?

Radon is present virtually everywhere in the world, including the United States, though some areas have higher radon levels than others. If your house sits in Iowa or southeastern Pennsylvania, beware that these regions have the highest radon levels in the country. You can check out your state and county on this detailed map of radon zones in the U.S., courtesy of the U.S. Environmental Protection Agency (EPA). Note that even the areas with the lowest average levels still have detectable levels of radon.

Why Is Radon Dangerous?

Radon is a radioactive element, and its radioactivity makes it carcinogenic, meaning that it’s been shown to cause cancer in humans. As a result, radon is the second-leading cause of lung cancer, following tobacco smoke. Unlike tobacco smoke, we can’t see, smell, or taste radon; but the fact that you’re not bothered by radon the way you are by smoke doesn’t mean you’re not breathing it, and it doesn’t mean radon’s not harming you and your family. The EPA estimates that radon causes approximately 20,000 cases of lung cancer in the United States annually. (All this time, some of you probably thought that spiders were the scariest things in your house, right?)

If you tested your home today, you’ll probably find radon. Typical outdoor levels are about 0.4 picocuries per liter of air; on average, homes in the United States will measure approximately 1.3 picocuries per liter—over three times the outdoor levels. At lower levels (up to about 2.5 picocuries), it’s up to you whether to do anything about your radon; however, having a low level doesn’t mean that you have safe levels, because there’s no such thing. Between 2.5 and 3 picocuries, you may want to act.

But at 4 picocuries per liter (that’s 10 times the average outdoor level), you have a real problem. Remember, this is a radioactive gas in your home. You, your family, and even your pets are all at risk for exposure and lung cancer.

This is part one of a three-part blog series. In part two, you’ll learn how you can test for radon levels in your home, school, or office.


Christopher Bloom, Communications and Marketing Officer, NCHHChristopher Bloom is NCHH’s communications and marketing manager. He joined NCHH in 2008 after nearly a decade in the real estate industry. In a previous role at NCHH, he coordinated a national Renovation, Repair, and Painting (RRP) training program, one of the most successful in the nation. He holds a Bachelor of Arts degree in English Textual Studies from Syracuse University.



Jo Miller , Senior Development and Communications Officer, NCHHJo Miller, GPC, NCHH’s Senior Development and Communications Officer, has worked as a part of the NCHH team since 2016. A 20-year healthy housing and lead poisoning prevention veteran, she has worked with lead and healthy homes programs throughout the country to build stronger partnerships, innovative approaches, and secure grant funds. 


January 26th, 2021 | Posted By , | Posted in Blog, Indoor Air Quality, Radon | Tagged , , ,