Granite Countertops - Radiation Danger?

Granite countertops have long been seen as a stylish upgrade to any kitchen. However, recent scientific testing suggests that homeowners who opt for this stylish upgrade could be putting themselves and their families at risk. The reason? Some granite used to make countertops may contain high levels of uranium, a radioactive substance that releases radon gas as it decays. With radon being the second leading cause of lung cancer after smoking, owners of granite countertops have a powerful reason to test for radon, making sure that they are protected from this serious health risk.

Most public experts agree that there is no safe level of radon, and that all radiation, from whatever source, has the potential to damage cells, particularly the DNA within those cells. Indeed, lifetime exposure even to low levels can often lead to cancer. In the case of a pernicious contaminant like radon gas, the EPA suggests aggressive measures such as ventilating all rooms where radon concentrations exceed nominal levels (2 pCi/ L) and strongly recommends remediation for concentrations exceeding 4 pCi/L

William J. Llope, Associate Professor of Physics at Rice University, has published research on radiation and radon from natural stone. He researched twenty articles published in peer-reviewed journals which presented radiation measurement data taken from natural stone granite. Although the majority of the samples in the studies indicated a low risk of radon (below 1 pCi/L), a few revealed significantly elevated radiation levels. Dr. Llope concluded that while most natural stone countertops would be found to be safe, a fraction would, under government guidelines, be considered absolutely unsafe.

The Build Clean Study

In another case involving Dr. Lynn Sugarman of Teaneck, New Jersey, Dr. Sugarman performed a routine home inspection, which revealed elevated levels of radon. She hired a radon measurement and mitigation technician to find the source. The technician, using a Geiger counter, demonstrated that her granite countertops were emitting about 100 pCi/L, a reading well above the EPA baseline. Dr. Sugarman has since had her countertops removed.

In another study, Sara Speer Selber of BuildClean, a company that tests Houston area kitchens for radon, tested a sample kitchen, revealing a radiation level of 3 pCi/L . Selber also tested a sample granite slab sealed in plastic, and the radon level was 17.3 piC/ L. This level is four times greater than what the EPA threshold.

So it's clear there is some contaminated granite already installed in kitchens across the U.S. What can the average homeowner do to check their countertop? Bringing in an outside testing company can be an expensive proposition. The best way to determine radon levels from granite counter tops is to test for them yourself using any one of several general purpose Geiger counters, such as the Gamma-Scout®, a widely available German made handheld.

Whichever brand you buy be sure it is sensitive to low levels of radiation, dosage rates that are typical of radon. And, also make sure it will measure all 3 types of radioactivity, alpha, beta and gamma radiation. Once you know your kitchen is safe, that granite countertop will once again be a place to prepare meals and not something to fear.