Most modern kitchens have them -- granite countertops.



Many people probably never thought twice about their safety, but some scientists say there are potential health risks with granite countertops.



"It's not something I would have thought of right away," said Paul Saxman of Lake Mary, whose home has granite countertops. "I realize it's a stone, but I wouldn't have thought that it would have been a problem."



But William Llope of Rice University said, "There's no question that there is the potential for risk."



Llope tests granite slabs to find out if they are radioactive. His testing shows most granite gives off harmless amounts of radiation, but he said "some of these granites I've measured resulted in doses that were hundreds or thousand times this natural background."



Radon gas is also a concern and can also be found in granite.



Saxman said he is aware of the dangers of radon, which is why he makes sure his kitchen is properly ventilated.



Paul John McCarthy is a scientist hired by the Marble Institute of America, which had him test 115 types of granite.



"None of those have shown a health risk," he said. "The data does not support the fact that there is a hazard from granite countertops in homes."



So given all the back and forth, how can someone find out if there is a problem in your home? The answer could be a simple test using a radon test kit.



The Marble Institute of America said it is working to address concerns and is developing a program that would require products to pass a rigorous test clearly showing they have been screened and approved for interior use.



The institute recommends testing your granite



The ground underneath your home is another source of radon. Home test kits will determine the level of radon coming from your countertop - but not radiation. That requires hiring a certified technician and will cost between $100 and $300.