FAQ

Radon is a radioactive gas that forms naturally when uranium, thorium, or radium, which are radioactive metals break down in rocks, soil and groundwater. People can be exposed to radon primarily from breathing radon in air that comes through cracks and gaps in buildings and homes. Because radon comes naturally from the earth, people are always exposed to it. 

Radon-222 is the decay product of radium-226. Radon-222 and its parent, radium-226, are part of the long decay chain for uranium-238. Since uranium is essentially ubiquitous (being or seeming to be everywhere at the same time) in the earth's crust, radium-226 and radon-222 are present in almost all rock and all soil and water.

The amount of radon in the soil depends on soil chemistry, which varies from one house to the next. Radon levels in the soil range from a few hundred to several thousands of pCi/L (picocuries per liter) in air. The amount of radon that escapes from the soil to enter the house depends on the weather, soil porosity, soil moisture, and the suction within the house.

How does radon get into a building?

Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon can become trapped and concentrated.

Openings which commonly allow easy flow of the gases in include the following:

• Cracks in floors and walls

• Gaps in suspended floors

• Openings around sump pumps and drains

• Cavities in walls

• Joints in construction materials

• Gaps around utility penetrations (pipes and wires)

• Crawl spaces that open directly into the building

Do radon levels increase with the age of a home?

No. The only way to know the radon level in any home, regardless of its age, foundation type, heating system, air tightness, or building materials, is to conduct a test. Elevated radon has been found in brand new homes and homes over 150 years old.

What is a radon mitigation system?

A radon mitigation system is any system or steps designed to reduce radon concentrations in the indoor air of a building.The EPA recommends that you take action to reduce your home's indoor radon levels if your radon test result is 4 pCi/L or higher.

What are the benefits of radon mitigation?

The primary benefit is reducing the risk of developing lung cancer.  Standard radon reduction systems are usually effective within 24 hours and maintain low levels as long as the fan is operating.  Another potential benefit of these systems is reduced infiltration of moist soil air with the radon, which may reduce the humidity level in the basement of the home.  Homeowners should consider correcting a radon problem before making final preparations to sell a home.  This often provides more time to address the problem and find the most cost-effective solution.  In addition, the current occupants--not just the buyer's occupants--will reap the benefit of reduced risk.