Radon home entry points.
Radon home entry points. In some areas, residual clay soil derived from Pennsylvanian and Permian limestone and phosphatic black shale may contribute to localized areas with elevated radon levels.

Radon—an invisible, odorless, and tasteless gas—comes from the breakdown of naturally occurring uranium found within soil, rocks, and groundwater. Radon is classified as a Class A carcinogen by the U.S. Environmental Protection Agency (EPA), meaning that scientific research has established that radon exposure causes cancer in humans, a health issue that many Kansas homeowners unknowingly face.

Elevated radon levels are found throughout Kansas. The EPA estimates that one in every 15 homes nationwide has an elevated radon level at or above the 4 picoCuries per liter (pCi/L) action level. In Kansas that number may be even higher. According to the Kansas Radon Program, approximately one in four Kansas homes may have elevated radon levels.

Radon levels cannot be predicted and often vary locally from house to house. While some geographical areas of Kansas tend to have radon levels below the EPA action level, every home in Kansas has potential for elevated radon.

The Kansas Geological Survey and the U.S. Geological Survey assessed the occurrence of uranium in Kansas to evaluate the radon potential in the state (Schumann, 1993). In general, above-average uranium concentrations are found in a number of Kansas rock formations.

Radon gas is capable of seeping through pores in the soil into the atmosphere or the interior of a building. Radon gas entering the atmosphere quickly becomes diluted, but the confined space of a structure, such as the basement, allows it to concentrate. Radon enters a home through sump pumps, cracks, joints, and pipes that penetrate the walls and floors of a home. Structures have a slight negative air pressure or suction relative to the soil, known as a stack effect, which sucks radon into a structure.

Radon also can enter a home if a water supply contains dissolved radon. Private water wells drawing from water with dissolved uranium or radium are most likely to have potential radon-associated health risks.

Additional information about radon—including fact sheets to help homeowners with frequently asked questions, test methods, real estate transactions, and mitigation techniques for both new and existing homes—is available from the EPA, the Kansas Department of Health Environment, and the Kansas Radon Program.


The Geology of Radon in Kansas: Kansas Geological Survey Public Information Circular 25.

EPA Indoor Air Radon Page

Kansas Radon Program, Engineering Extension

Kansas Department of Health and Environment Radon Information

Schumann, R. R., 1993, Preliminary geologic radon potential assessment of Kansas; in, Geologic Radon Potential of EPA Region 7, R. R. Schumann, ed.: U.S. Geological Survey, Open-File Report 93-292-G, p. 71-94.