Published on April 9th, 2009 | by Linda Kincaid, MPH, CIH5
Radiation and Radon from Green Building Materials
Building with reclaimed building materials is a great way to reduce the environmental footprint of a building. LEED and GreenPoints both award points for use of reclaimed materials. However, some reclaimed materials can be radioactive.
Fly ash is the material left over from burning coal. A waste product with little other use, it is sometimes added to concrete or bricks. However, if the original coal contained radioactive isotopes, those isotopes will be greatly concentrated in the ash.
A block of high rise condominiums in Florida have elevated radon gas. Typically, radon is not a problem in upper levels. However, these condos have elevated radon due to emission from the concrete structure itself. The problem is exacerbated by inadequate ventilation in the units. Radon scientists are working with ventilation engineers to develop a ventilation system to reduce radon in the dwellings.
Granite counters are an unexpected radiation and radon source for a few homeowners. A homeowner in the San Francisco Bay Area had Jupurana Bordeaux granite that emitted gamma radiation at 25 times background radiation. Lab tests showed that her granite contained as much uranium as uranium ore. The granite increased the radon concentration in her kitchen by three fold.
Fireplaces tend to emit slightly more radiation than the surrounding materials. We have found a few fireplaces that emit modest amounts of radon gas. The source is most likely small amounts of radium in the fly ash used to manufacture the brick. In general, these fireplaces do not emit enough radon to raise the concentration in the home.
Fortunately, most building materials are not particularly radioactive, and most do not emit substantial amounts of radon. The European Commission has produced a guideline for radiation in building materials, but the U.S. does not yet have a similar standard. For now, a homeowner that is concerned about radiation in building materials can consult an industrial hygienist or health physicist.
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