The Health Physics Society (HPS) this week questioned the science and methodology behind a recent New York Times article on radon levels in granite countertops.
HPS, a scientific and professional organization whose members specialize in radiation safety, called the radon levels cited in the article "very odd." The July 24 New York Times article, "What is Lurking in Your Countertop?" reported that a radon measurement contractor stated that exposure from granite countertops in the kitchen of a summer home in upstate New York were ten times higher than in other areas of the residence and attributed the elevated levels to uranium in the granite countertops. The article also reported that radon levels in the kitchen of the home were reported to be 100pCi/L, compared to basement levels of 6pCi/L.
In a special bulletin posted on its Web site, HPS strongly took issue with those numbers, as follows: 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,HPS said.This concentration is less than one-eighth the average radon gas concentration in U.S. homes and is well below the Environmental Protection Agency (EPA) guideline of 4 pCi/L.
"There are some alerting factors when we see measurements and statements like this," the bulletin continued. "First, investigation determined that the measurement procedure was not valid. The procedure used by the contractor was not appropriate (as per EPA radon measurement methods) and did not provide a real idea of the amount of radon in the ambient kitchen air."
"Second, even if the measurement had been valid, one measurement result based on one type of granite countertop in one particular home is not an indication of radon exposure in any other kitchen with a granite countertop. What is needed is to measure many types of granite. So some members of the Health Physics Society did."
"It isn't surprising that granite emits radiation," the bulletin said. No do other items in our households. The amount of radiation emitted from granite can vary depending on the amount of natural uranium and/or thorium concentration."
The HPS special bulletin reaffirms what a growing number of respected experts, as well as respected scientific research, have also concluded: consumers can be confident about the safety of granite countertops in their homes. Largely because of the New York Times article and similar media reports, granite and radon has become a confusing and emotional issue for consumers, many of whom are afraid to install granite countertops in their homes or are worried about the countertops they may already have. Yet,according to some of the most noted authorities on granite, radon and risk ?their concerns are unfounded. The bottom line, they agree, is this: When it comes to countertops, the science proves that there is no reason for consumers to make health issues a factor in whether they choose granite.
For additional information, and to read the full bulletin and letter from the President of the Health Physics Society to the New York Times about the article on radon in countertops, go to
Source: MIA
