Is radon gas emitted from clay brick masonry?
When earlier reports of the danger of radon gas in homes reached the media many people believed that building materials such as clay brick, concrete block, or concrete were the primary source of radon. The Brick Institute of America (BIA) issued an Engineering and Research Digest that discusses the problem of radon in buildings. According to the digest, tests showed that building materials accounted for less than 1% of the radon gas in buildings. The majority of radon gas, 95%, came from the soil and subsoil beneath building foundations.