DOH: Air Quality Division - Radon Fact Sheet

What is Radon?
Radon is a naturally occurring, invisible, odorless gas that comes from deposits of uranium in soil, rock and water. It is harmlessly dispersed in outdoor air, but when trapped in buildings, it can be harmful, especially at elevated levels. Radon is a radioactive decay product of radium, which is itself a decay product of uranium. Uranium and radium are both common elements in the soil.

Where is Radon found?
The primary source of high levels of radon in homes is the surrounding soil. Radon has been found in elevated levels in homes in every state. The US Environmental Protection Agency estimates that as many as one in 15 homes across the US has elevated radon levels.

How does Radon get into my house?
Warm air rises. When this happens in your home, it creates a vacuum in the lower areas of the house. Nature abhors a vacuum, so something must rush in to fill it. In the case of your home, air seeps in from the soil around and under the house, and some air is sucked in through openings (cracks, doors, windows) on the lower levels. Radon gas enters the same way air and other soil gases enter the home; through cracks in the foundation floor or walls, hollow-block walls, and openings around floor drains, pipes and sump pumps.

What are the health effects of Radon?
Exposure to radon is the second leading cause of cancer in the US Radon can be inhaled into the lungs, where it undergoes radioactive decay. As it decays, radon releases tiny bursts of energy called alpha particles, which can harm sensitive lung tissue by damaging the DNA. This damaged DNA can lead to lung cancer.

How is Radon measured?
Radon is measured in picocuries per liter of air (pCi/L), a measurement of radioactivity. The EPA and the Center for Disease Control and Prevention recommend that homes with radon levels over 4 pCi/L be fixed.

How do I find out if my house has Elevated Levels of Radon?
Testing your home for radon is as simple as opening a package, placing a radon detector in a designated area, and after the prescribed number of days, sealing the detector back in the package. Fixing a radon problem is usually just a matter of caulking cracks along basement foundations, sealing leaks around pipes, and taking other steps to prevent radon from entering the house through places where it is in contact with the ground.

"I don't have a basement, I probably don't have a Radon problem."
Radon can seep in from soil anywhere around or under a home, regardless of whether your home has a basement, a crawl space, or is built slab-on-grade. The US Environmental Protection Agency (EPA) and the Surgeon General recommend radon testing for all types of homes at or below the third floor.

"I don't live in an area designated as a high Radon zone, so my home won't have a problem."
The US EPA and the US Geologic Survey conducted a survey of radon potential across the United States. They broke the country down into three zones according to their potential for high indoor radon levels, with Zone I having the highest radon potential. It is true that homes in Zones I and 2 have a statistically high chance of having elevated levels of radon. However, the fact is that elevated levels of radon have been found in homes in all fifty states. The only way to know whether radon exists in elevated levels in your home is to test.

"Two of my neighbors have tested their homes for Radon and they don't have high levels, so I probably don't either."
Radon levels can vary considerably from house to house, even on the same street. It is nearly impossible to predict the exact nature of geologic soil deposits and the extent to which soil gases will seep into and be retained by a specific house. The only way to know whether radon exists in elevated levels in your home, and to protect your family from radon, is to test.

"There doesn't seem to be much proof that Radon is a serious health problem."
The science on radon has been formidable over the years, but never before have we had such overwhelming scientific consensus that exposure to elevated levels of radon causes lung cancer in humans. In February of 1998, the National Academy of Sciences (NAS) presented the findings of their Biological Effects of Ionizing Radiation (BEIR) IV Report: "The Health Effects of Exposure to Indoor Radon". This new report by the NAS is the most definitive accumulation of scientific data on indoor radon. The report confirms that radon is the second leading cause of lung cancer in the US and that it is a serious public health problem. The study supports US EPA estimates that radon causes about 15,000 lung cancer deaths per year.

"I don't have time to test for Radon!"
Testing is as simple as opening a package, placing a radon detector in your home in a designated area, and after the prescribed number of days, sealing the detector back in the package and mailing it to a lab. The whole process only takes a few minutes of your time.