My friend Connie called today. She is remodeling her country house kitchen, wants to do it as a green
remodel, and prefers to use granite for its natural and longevity qualities, but is concerned about the possibility that the granite she has chosen emits Radon. Did I have a list of countries from which one should avoid getting granite slabs?
Connie- I don't have such list, but I have some knowledge about naturally occuring Radon. For the record, I tested my granite slabs for Radon, 6 months ago, under the pilot program in Houston conducted by the non-profit Build Clean, and the tests were negative. It was important to ascertain this, because - unlike Connie's 100 year old farm house that is built like "swiss cheese"- my green, Energy Star, high efficiency home is built tightly, and Radon can and will acumulate in the indoor air.
Is it possible that we are endangering our families by introducing natural stone in our homes? It is.
The best research on this subject has been done by Rice University Professor W.J. Llope, who published his research in April of 2008. According to Professor Llope,"naturally occurring Uranium nuclei decay into
an element called Radium, which produces an unstable gas called Radon. Breathing airthat contains radon thus deposits radioactive elements directly into the soft-tissues of the lungs and can cause lung cancer."
Is it possible to test the material before purchasing it? Not easily at the moment, but that time is coming, and it will depend on consumers getting serious about ascertaining that these natural materials don't come from quarries that have a high ocurrance of Radon. I'd like to see testing happening before the imported slabs arrive at our ports, given that in this capitalistic nation, if the material is here, it will show up in some unsuspecting victim's home.
If you are ready to know if your existing granite or stone countertop or floors are emitting radon ( it takes guts to deal with the possibility of having to change your countertops or floors), hardware stores sell Radon testing kits. Make sure that the one you buy states "“meets EPA requirements" and that it is listed in the National Radon Safety Board's devices list.
As for acceptable concentrations of Radon in your house, Dr. Llope states:"The EPA suggests
remediation for radon concentrations exceeding 2 pCi/L, and strongly recommends remediation for concentrations exceeding 4 pCi/L. These administrative limits are our best guide of what levels of exposure are dangerous and what levels aren’t. However, there is no safe amount of radiation or radon."
What can we do if we find the aforementioned levels of Radon in our homes?
If you own natural stone countertops, here are some suggestions from Dr. Llope's report:" Ventilate your home as often as possible by opening windows - this exchanges potentially radon-laden air from
the inside of your home with essentially radon-free air (at least in the Houston area)
from the outside. The radon concentration in an unventilated volume of air reaches its
saturation density in about 27 days - so open your windows for a half-day once every few
weeks. Make sure that you follow the manufacturer’s recommendations on the regular maintenance of your countertops, which typically call for regular resealing of the surface (once per year)."
Connie, I will add that before installation, the granite slabs can and should be sealed on all four sides. I don't believe in too much regulation, but when it come to our collective health, green building equals best practices, and our government needs to protect our people from ending up with high radon stone. Thank you for asking Connie.
