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What is radon?

Radon is a toxic, radioactive gas with no color, odor or taste that forms from the normal decay process of uranium, which is present in most rocks and soil. Uranium slowly breaks down to other products, including radium, which then breaks down to radon. This decay process produces alpha, beta, and gamma radiation.

Some of the radon moves to the soil surface and enters the outdoor air or enters a house or building through cracks in the foundation, while some radon remains below the soil surface and enters the groundwater. Radon levels in the soil range from a few hundred to several thousand pico Curies per liter (pCi/L). The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, foundation integrity, and the suction within the house.

What diseases are caused by radon exposure?
Radon is the second leading cause of lung cancer after smoking, and in fact, concurrent exposure to radon plus smoking leads to an even higher risk of lung cancer. Lung cancer generally occurs after many years of exposure.
How and where are people exposed to radon?
People are most often exposed to radon through inhalation of contaminated indoor air. According to the Environmental Protection Agency, nearly one in fifteen homes has an elevated level of radon. Outdoor air can contain radon as well but in smaller concentrations. Drinking water may contain radon, although usually in lesser concentrations than in air. Radon can leach from the soil into underground well water and then enter a house or building through the water supply or escape from soil as a gas and enter the house or building through cracks in the foundation. Occupational exposures to radon, such as found in underground uranium miners, lead to a higher risk of disease.
Is there a safe level of radon?

The EPA recommends a level of less than 4 pico Curies per liter (pCi/L) of radon in indoor air; however, there is no established safe level of radon. The EPA recommends remediation (taking action to lower the level) immediately if the radon level is greater than 4 pCi/L. Furthermore, EPA suggests that homeowners consider fixing radon levels between 2 pCi/L and 4 pCi/L to maintain a radon level of below 2 pCi/L. The average radon level in homes in the United States is 1.3 pCi/L, but certain parts of the country have higher average radon levels than others.

Pennsylvania has one of the most serious radon problems in the country. An estimated 40 percent of Pennsylvania homes have radon levels above Environmental Protection Agency’s action guideline of 4 picocuries per liter.

How do I know if I am exposed to radon?
You can find out if you are being exposed to radon by having the air in your home tested by a certified radon testing service. Water, a less significant source of radon, can also be tested. Routine medical testing does not detect radon in the human body. Your doctor will not be able to tell by examining you or testing your blood if you have been exposed to radon. There are also home testing kits available and some states give them to free to homeowners.
If my home’s radon level is too high, what can I do?
If the radon level in your home is 4 pCi/L or higher, contact a certified radon remediation service right away. Since no safe level of radon exists and radon levels less than 4 pCi/L still carry a risk, it is advisable to remediate levels below 4 pCi/L in order to achieve a level of 2pCi/L or less.
Where can I get more information on radon?
The following are excellent sources for information on radon, testing, and remediation:

United States Environmental Protection Agency
World Health Organization on Radon

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