The secret to the dangers of granite countertops?

July 30, 2008 — They’re beautiful and durable, but are those expensive granite kitchen countertops popular with home builders and renovators also a health hazard?

Some researchers say they might, but a group representing the granite industry counters that the claims are “alarming” and that their research is nothing more than “junk science.”

The question is whether certain granite countertops emit dangerous levels of radiation, especially radon gas, which is the second leading cause of lung cancer after smoking.

Experts agree that most granite countertops emit some radon gas and even other types of radiation. The question is whether the level at which they do so affects cancer risk.

Dr. Michael Kitto, a New York State Department of Health research scientist, said only a small percentage of the granite samples he tested released radon

But he added that some of his samples showed The level was high enough to make him alert.

“I’m not putting them in my house,” Kitto tells WebMD.

Worries about countertops are not new

Worries about the safety of granite kitchen countertops are not new.

“Mesa stories come out every 10 years or so,” Dr. David J. Brenner, director of Columbia University’s Center for Radiation Research, tells WebMD. “This is about the third time I can remember it has appeared.”

A report in the New York Times last Thursday investigated the issue, sparking concerns.

The story refers to research by Rice University physics professor William Lopp, Ph.D., that found potentially dangerous levels of radiation in some test samples of granite used for countertops.

In response to the Times

i> article, the Marble Institute of America (MIA) issued a statement on its website claiming that the EPA agrees with industry claims that studies such as Llope represent “junk science” statement.

Under the headline “EPA confirms granite countertops pose no significant health risk, undercuts ‘junk science’ fear-mongering,” the article claims the EPA issued a statement Friday saying the same .

While confirming that the EPA’s website addressing radon and countertops had changed late last week, EPA spokesman Dave Ryan declined to discuss the institute’s claims in an interview with WebMD.

“I’m not going to comment on anything they say,” he said. “What I’m saying is that our position is on the website.”

As of early this week, that position was much more nuanced than the institute claimed, noting that “some granite used for countertops may have The effects of indoor radon levels vary.”

“However, at this time, EPA believes there are insufficient data to conclude that the types of granite commonly used in countertops are significantly increasing indoor radon levels,” statement


In response to the question, “Is radon levels in granite dangerous to humans or animals?” The EPA states, “While radon levels from granite are generally not high, Potential health risks, too many variables to generalize.”

Not a cause for alarm, experts say

Colombia’s Brenner believes radon emissions from granite countertops are highly unlikely A health risk because they cover such a small area.

“The biggest source of radiation in the home is really radon,” he said. “But it’s not radon from countertops, it’s radon from the ground.”

Radon is an odorless, tasteless, colorless radioactive gas that is produced by the natural decay of uranium in soil, rocks and water . All agree that the biggest risk a homeowner faces is radon leaching into a home from the ground.

Most people who live in areas with high radon concentrations, such as Pennsylvania and upstate New York, are well aware of the potential risks, says Brenner.

“You can’t get a mortgage on a cheap jersey wholesale without a radon test,” he said. “If radon goes above a certain level, you have to take action.”

The risk of radon comes from inhaling radon into the lungs, and Brenner says any radon from granite countertops can quickly diffuse into the air .

“Even a countertop that is 10 or 100 times higher than average contributes very little to radon.”

Others think the fear is justified< p> But Llope at Rice University is not so sure.

Llope tells WebMD that he started testing granite samples “on his own time” after seeing a story about granite countertops and radon gas. Houston news show.

He uses a special spectrometer to measure gamma radiation emission.

In a recently published review of radon testing by others, Llope reported that 92 of 95 granite samples tested had no or very little radon. Two samples had elevated emissions levels that were still considered safe, and one sample had emissions levels slightly above what the EPA considers to be of concern.

Like Kitto, Llope found elevated levels in very few granite samples he personally tested.

But he tells WebMD that even a small portion of the granite used to make countertops emits unsafe radon or other radiation that could be dangerous to thousands of homes.

“Granite is so popular that it now comes from all over the world,” he said. “It’s no surprise that granite from nearby uranium mines could cause problems. But testing has not been done.”

More granite testing needed

According to American Marble Research According to spokesman Jim Martinez, 2,000 different types of stone from quarries around the world are sold as granite in the United States.

Only a fraction of the samples have been tested for radon or radiation levels at best, but a recent test of 13 types of granite commonly used in countertops found no radon or very low levels of radon gas.

Testing, paid for by MIA, samples 85 percent of the granite used in U.S. kitchen countertops, Martinez said.

He says MIA-funded research represents the only “true” scientific research, because no one else wants to pay for high-quality research.

“(Our) research has consistently shown that granite poses no health risks,” he said.

But Keto said there’s no way to know if all granite countertops are safe because so few samples have been tested.

“Now, it’s important to be able to understand the scope of the problem or even if there is a problem,” he said.

Llope agrees that more samples need to be tested.

“The industry says there is no danger, but how can they make that leap of faith when granite comes from all over the world and only a small portion has been tested?” he said. “How could they possibly know?”

Radon testing, experts say

EPA recommends that all households be tested for radon in indoor air, and researchers contacted by WebMD agreed that testing can cause concern Homeowners with granite countertops can rest easy.

Suggestions for using a self-help radon test kit, available at hardware stores and online, include:


  • In the basement or lowest part of the home Do a test to see if radon is coming from the ground.
  • Another test is performed in the bedroom to determine background radon levels.
  • Place a test or two in the kitchen, one near the granite surface and the other farther away.

“Home kits test for radon, not (other) radiation; but if the results are negative, you can assume you don’t have a radiation problem,” Llope said. “If the results are positive, you should probably have the home professionally tested.”

The American Association of Radon Scientists and Technologists lists the names of qualified professionals who work with radon and radiation