How often is indoor radon a problem?
Nearly one out of every 15 homes has a radon level the EPA considers to be elevated. Because most people spend as much as 90 percent of their time indoors, indoor exposure to radon is an important concern. How does radon get into a building? Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon can become trapped and concentrated.
71% of the homes in Iowa have radon concentrations above the action level of 4.0 pCi/L, which the EPA (Environmental Protection Agency) considers to be unacceptable (4 pCi/L or greater). Because most Americans spend as much as 90 percent of their time indoors, exposure to Radon Gas is an important concern.
