The potentially harmful effects of granite have long been disputed in the scientific community, however with the advent of a granite study by a RIce University physics professor, there appears to be mounting evidence to support the claim that granite may have harmful effects. Professor William Llope's study on the radiation levels emitted by granite samples used in home construction found potentially dangerous levels of radiation in some of the samples tested. These levels of radiation are harmful because they can contribute to the likelihood of developing cancer.

On the Other: Most Granite Samples Do Not Harmful Levels

The New York State Health Department, however, came to a somewhat different conclusion from their study on the potential health hazards of granite countertops. Under the direction of research scientist Michael Kitto, Ph.D., the study found that only a very small fraction of granite samples tested emitted radon at levels above those considered safe. Thus, the vast majority of samples tested would not emit dangerous levels of radon if used in countertop construction.

Bottom Line

While the New York State Health Department study found that the majority of granite samples tested emitted levels of radon well below that which is considered safe, the study did confirm that some samples emitted radon above that level. The Environmental Protection Agency states that granite used for countertops "may contribute to indoor radon levels." Thus although the chances that any one granite countertop will emit potentially harmful levels of radon is low, there is still a chance.

Source:

WebMD.com: Granite Countertops: A Recipe For Danger?

Rice University: Houston Chronicle: Be Wary of Granite That Glows

More Information:

NewYorkTimes.com: What's Lurking In Your Countertop?