Sunday, May 18th, 2014
It is reasonable to ask if using granite in our homes adds to the risk of radon exposure. The EPA thinks not.
Over the last fifteen years, granite has become a very popular countertop surface and is featured on home–improvement television shows. Granite is a strong, solid surface rock which can resist heat, is easy to clean and maintain and comes in a wide variety of colors and patterns.
Granite, like other rocks, contains radioactive substances such as uranium and radium. As uranium breaks down into radium and radon gas, the radon gas reaches the earth’s surface through the soil. In a pamphlet regarding granite use in homes, the EPA notes “It’s important to know that radon originating in the soil beneath homes is a more common problem and a far larger public health risk than radon from granite building materials.”
Radon gas enters buildings, including our homes, where it can be inhaled into the lungs, and cause lung cancer. The United Nation's World Health Organization (WHO) says that radon is a worldwide health risk in homes. Dr. Maria Neira of WHO said that "Most radon-induced lung cancers occur from low and medium dose exposures in people's homes. Radon is the second most important cause of lung cancer after smoking in many countries."
The EPA has determined that a radon measurement of 4 pCi per liter of air may be dangerous and recommends that all residences be tested for radon. If the radon level in the lowest livable area is found to be 4 pCi/L or above, radon mitigation is recommended. There are a number of fairly simple and economical building modifications which can reduce interior radon levels by as much as 99%.
Homeowners may use a radon testing kit, or employ a certified radon specialists like Next Step Environmental Services LLC. It is likely that lower levels of a home, like a basement or ground floor, will have higher measurements than a third story or above.
The EPA recommends radon testing for the lowest livable area of your home. Bathrooms and kitchens, the household areas most likely to contain granite countertops, are not recommended as testing sites, because heat and moisture can produce inaccurate results. Those are also areas which are likely to be well-ventilated, with windows or exhaust fans.
However, testing kits may be placed in a room next to a kitchen or bath. The results of such tests generally reveal that any radiation which could be coming from granite surfaces in kitchens or baths is simply part of the ordinary background radiation found throughout the home.
Information about radon gas and granite countertops has recently been in the news. Suppliers of alternative countertop materials have cited safety concerns about radon as a reason for abandoning the use of granite. But the EPA has concluded that although granite, like many stone surfaces, emits some amount of radon gas, the amount is so small that there does not need to be a bar on using natural stone surfaces in the home.