Granite Counter Tops and Radon

What about radon released from granite counter tops?

​1.  Does the Health Physics Society (HPS) believe there is a danger of radon gas or associated radiation being emitted from granite counter tops?

HPS radiation from Granite Countertops Summary:

Assuming a relatively tight house with an air change rate of 0.5/hr and using average measured dose rates from granite countertop slabs, the estimated radon concentration in kitchen air would be 0.13 pCi/L.  this concentration is less than one-eighth the average radon gas concentration in U.S. homes and is well below the Environmental Proteaction Agency (EPA) guideline of 4 pCi/L.

2.  Does the EPA believe there is a danger of radon gas or associated radiation being emitted from granite counter tops?

Granite is a natural mineral formed by the earth's geological processes.  It is quarried and processed to produce commercial products such as counter tops.  It is possible for any granite sample to contain varying concentrations of uranium that can produce radon gas, a source of alpha and beta particles and gamma rays.  Some granite used for counter tops may contribute variably to indoor radon levels.  At this time, however, EPA does not believe sufficient data exist to conclude that the types of granite commonly used in counter tops are  significantly increasing indoor radon levels.  While radiation levels are not typically high, measurement from different granite types may reveal higher than expected levels on a case=by-case basis. 

What advice does the EPA have about radon for consumers who have granite counter tops?

While natural minerals such as granite may occasionally emit radon gas, the levels of radon attributable to such sources are not typically high.  EPA believes the principal source of radon in homes is soil gas that is drawn indoors through a natural suction process.  to reduce radon risk you should first test the air in your home to determine the radon level.

Source:  California Department of Health Services, Indoor Radon Program