Many homeowners are increasingly worried about the level of radiation they may be getting from their granite countertops. Granite is very popular as material for buildings and homes, especially as kitchen countertops because of their beauty, durability, and function. Some granite countertops have dangerously high emissions of radiation, particularly radon gas. This is a colorless gas that comes from decaying uranium. It is associated with high risk of developing lung cancer. The question is, is this growing concern based on scientific evidence?
Here are some important facts about granite and radiation that any homeowner should know
Fact 1: Radon is dangerous
Radon gas is undoubtedly dangerous. Research indicates that is only second to cigarettes as the leading cause of lung cancer. People that smoke are especially at risk, because their lungs are already vulnerable to the disease. Children and developing fetuses are also in danger when exposed to high levels of radon gas as well as other forms of radiation.
It should be noted, though, that research into the levels of radon gas and radiation in general from granite indicates that granite does not put human health at risk. While it is possible that a granite countertop that exhibit high levels of radioactive emission can put anyone that regularly comes into proximity to it for at least two hours a day, it is highly unlikely. Some experts consider it less dangerous than flying frequently, or spending a considerable amount of time in a basement or anywhere close to the soil where uranium is always present in small amounts.
Fact 2: Granite contains radioactive materials
However, it is undeniable that granite does contain radioactive materials, some more so than others do. Granite is the most abundant type of natural stone in the world. It forms as a result of magma cooling over millions of years under intense pressure and heat. According to the Marble Institute of America (MIA), granite is comprised of many elements. Including uranium as well as other radioactive materials such as thorium and potassium. However, these radioactive materials are typically present in such tiny amounts that they are negligible. In fact, all natural stones of any type contain radioactive materials as a matter of course. Despite this, they pose no danger to humans. Granite may pose even less of a threat than marble or limestone, because granite is a lot less porous. Any uranium that may be lurking in its depths will have no opportunity to release any radon gas it produces.
Homeowners should also realize that the absence or presence of radioactive emissions of any level does not mean that they are safe or dangerous. The Nuclear Information and Resource Service states, “All life on Earth is exposed to and impacted by natural sources of ionizing radiation. …When a living being absorbs it, that individual has received a “dose” of radiation….one radiation particle can cause great damage to a single cell; that damage can even lead to a person’s death, while registering a dose to the total body of zero!” Even if you are exposed to higher than normal levels of radiation from granite, it does not mean you are going to die. The fact is, no one really knows precisely how and what the effect radiation can have on humans.
Fact 3: Radiation levels in granite are extremely low
Radiation and health experts agree the radioactive emissions of a vast number of decorative granite slabs are so low. They are negligible. They are less dangerous in this sense than what most people are exposed to from the soil or form cosmic radiation. The amount of radiation in granite is much lower than the radiation exposure from smoke detectors, X-rays, and the luminous dials in watches.
According to the Nuclear Regulatory Commission and Environmental Protection Agency (EPA), the average person typically absorbs approximately 360 milliliter of radiation annually from manufactured and natural sources. It is estimated that people that reside in proximity to nuclear reactors get an added 100 milliliter a year. You receive an additional 3 milliliter of cosmic radiation every time you fly from Los Angeles to New York. The EPA puts the safety threshold for radon gas levels in the home at 4 epicures, which poses the same risk for lung cancer as half a pack of cigarettes.
Some people consider a granite slab or countertop that emits in excess of 10 times the normal radiation as “hot.” While it isn’t really hot, it refers to the risk of harm from radiation. In order for a “hot” granite slab to increase your radiation absorption by a fraction of a millirem, you would have to stay close to or touch it for an hour. Radiology researchers place the health risk posed by “hot” granite countertops in the order of “one in a million,” more unlikely than a direct hit from a lightning strike.
Fact 4: Exotic granite may be the problem
There is still the issue of the rising number of reports from both homeowners and radon inspectors of granite slabs going significantly beyond acceptable levels of radiation to the EPA recently. It is believed that this is the result of the introduction of exotic granite slabs into the US. MIA president Jim Hogan says, “We know the vast majority of granites are safe, but there are some new exotic varieties coming in now that we’ve never seen before, and we need to use sound science to evaluate them.” The MIA is currently in the process of addressing this problem by designing a testing protocol.
Granite and radiation is the flavor of the month for scaremongers, but many homeowners are not buying into the hype. Many, including those that have personal experience with granite with high levels of radiation, continue to prefer granite countertops. Before installing any granite slab, they have it tested first.
The service fee of a certified inspector from the American Association of Radon Scientists and Technologists ranges from $100 to $300. Homeowners will rest more easily if they can get an assurance that their kitchen countertops are safe. They can also buy a home radon testing kit from the Environmental Protection Agency. The cost is about $20. It may be a waste of time or money, but there is no substitute for peace of mind.
Granite Countertops and Radiation
A variety of materials may be used to make countertops, including artificial materials, quartz, marble, slate and granite. Granite’s durability and decorative appearance make it a popular building material in homes and buildings.
About Granite Countertops and Radiation
Granite, like any other stone, may contain veins of naturally occurring radioactive elements like uranium, thorium, and their radioactive decay products. These trace concentrations may vary from stone to stone, or even within a single slab of granite.
If present, uranium, thorium or radium will decay into radon, a colorless, odorless, radioactive gas that may cause lung cancer. Radon released from granite building materials can be released over the lifetime of use but typically will be diluted by ventilation.
In addition to radon, naturally occurring radioactive elements in the granite can emit small amounts of beta and gamma radiation. However, any radiation present would decrease quickly with increasing distance from the source. It is extremely unlikely that radiation from granite countertops would increase annual radiation doses above normal, natural background levels.
Identifying Radiation in Granite Countertops
Identifying the presence and concentration of radioactive elements in each specific granite countertop requires sophisticated instruments. These instruments require proper calibration and a knowledge and trained user to interpret the results. If you are interested in learning about testing methods, information is available from your state’s radiation protection program.
Radon originating from the soil beneath homes is a more common problem and a far larger public health risk than radon from granite building materials. Radon is the second leading cause of lung cancer and is estimated to cause tens of thousands of lung cancer deaths in the U.S. each year. To reduce the risk of lung cancer from exposure to radon, EPA recommends testing all homes for radon and mitigating high levels, regardless of whether the home contains granite countertops. View the updated “Citizen’s Guide to Radon” for more information about testing your home.