Radon gas is drawn into a home from the surrounding soil through any cracks, gaps, and penetrations in a home's foundation wall or floor. It also can seep directly through pores in concrete. Any home, of any age, in any state can have elevated radon levels. It ultimately depends on the design and way your home interacts with the surrounding soil. Radon levels are usually highest in the basement or crawl space as this level is closest to the source of the radon. Therefore, people who spend much of their time in basement rooms have a greater risk for being exposed.