Yes, “some” pieces of granite “may” emit naturally occurring radioactive elements such as radium (radon), uranium and thorium. Some granite contains more of these elements than others and this is just a fact about any igneous rock. The process for granite starts by forming as molten rock, then cooled and solidified over tens of thousands of years. This slow forming granite has beautiful and distinctive patterns in many colors from the various minerals growing into crystals.
Does this mean you should avoid buying or rip out your granite tops?
No, but some people have done so because of reports the Environmental Protection Agency (EPA) has been receiving from Radon Inspectors about granite countertops with radiation measurements well above the normal background levels.
EPA states action should be taken in a home where radon is seeping into a house’s basement from the naturally decaying uranium underground that exceeds a measurement of 4 picocuries per liter of air. Equivalent to smoking half a pack of cigarettes per day. This is found in types of ground that are heavily infused with rock formations. Sandy soil doesn’t have a radon issue.
Most granite tops are safe and have no measurable readings, others are within the range of normal or low readings, but there seems to be a relationship between granite with dark and/or exotic colors to higher radiation measurements. For example, the New York Times reported on a salmon-colored granite that had readings of 100 picocuries per liter while the homeowner’s basement, where radon is expected to be high, was only 6 picocuries per liter. Now does this mean all salmon-colored granite will have these readings? No, each cut of granite will be different in the amount of radon gas being omitted, if any at all.
If you are concerned with countertops giving off any level of radiation, look into natural quartz countertops. However, like any natural stone, there may be a trace amount of radon escaping from them. So seek out quartz countertops that are actually made from resins, glass and quartz and are sealed when manufactured. When countertops are permanently sealed, if any radon was present, none will be released.
Bill Lauto, GTG
Environmental Scientist at
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