But when it enters a house through drains or cracks in the foundation, floors and walls, it can build up. Radon's radioactive byproducts may damage lung tissue and cause lung cancer if inhaled over time. Because there is at least some uranium in all soil, radon can be found everywhere. Homes that are tightly sealed for energy efficiency or are built of stone and brick are likely to have more radon, as are homes with basements. According to Kenneth L. Mossman, Ph.D., a professor of microbiology at Arizona State University in Tempe, location is not a reliable predictor of radon levels.
Controversy regarding radon abounds throughout the scientific community.
Ninety-nine percent of homes in the United States have radon levels below those that have been shown to have any kind of health impact. Mossman's view is in line with the conclusion of many scientists who have conducted radon research studies, but is diametrically opposed to the EPA's contention that radon is indeed a health threat. For lower radon concentrations, the recommended action is to increase ventilation throughout the home and seal off any cracks or openings that lead directly from the ground into the house. Our comfort zone, our cocoon, a safe retreat from the chaos of the outside world. Well, not necessarily.