Earlier, Llope was cited by Houston Chronicle as finding that some granite countertops generate gamma radiation and radon gas at a level that is considered dangerous by the U.S. government.

In its statement, the MIA categorized the studies as junk science and cited new U.S. Environmental Protection Agency (EPA) statements to say that radon gas and radiation released from granite countertops do not pose a risk.

The MIA represents producers and quarriers, fabricators, installers, distributors and contractors worldwide in the natural dimension stone industry.

"While natural minerals such as granite may occasionally emit radon gas, the levels of radon attributable to such sources are not typically high," the EPA statement was quoted by MIA as saying.

"EPA believes the principal source of radon in homes is soil gas that is drawn indoors through a natural suction process.”

In an EPA statement cited by the industrial organization, the EPA acknowledges that the "it is possible for any granite sample to contain varying concentrations of uranium that can produce radon gas.  Some granite used in countertops may contribute variably to indoor radon levels.”

But the government agency goes on to say that it "has no reliable data to conclude that types of granite used in countertops are significantly increasing indoor radon levels."

The MIA also quoted a statement by the EPA to discount worry about the radiation from granite countertops. "Construction materials such as concrete, cinder blocks, bricks, and granite contain small amounts of radioactive materials that are found naturally in the materials used to make them," meaning that radiation is not unique with granite countertops.

"Every time researchers have applied rigorous scientific standards to testing, the results have found that granite countertops pose no risk," said Jim Hogan, president of the MIA.

"Repeated studies have found that granite is safe. Unfortunately, some recent junk science being reported as fact only serves to panic the public, not inform it. Our goal is to end this fear mongering by facilitating the creation of a real scientific standard for testing granite countertops."

Llope tested 55 stones of 25 varieties of granite stones purchased from local dealers and found some homeowners would be exposed to 100 millirems of radiation in just a few months, exceeding the annual exposure limit set by the Department of Energy for visitors to nuclear labs.

Llope did not publish the names of the granite countertops that he found are most dangerous, but he was cited as saying that the highly radioactive varieties include striated granites from Brazil and Namibia.

In a document published on his website, Llope said there is no safe threshold for radiation and the general guideline is that each rem of radiation would cause cancer in 4 people in a population of 10,000.

Some granite countertops he tested released one rem of radiation in just 250 hours or 10 days.

But the MIA cited two recent studies by researchers at the University of Akron and Consumer Reports as finding no grounds to fear granite countertops because radon gas did not seem to be an issue.

It is not immediately clear if these two studies tested radiation from granite countertops.