Q. Is radon real? Yup. Radon is a naturally occurring radioactive gas that forms as the result of the breakdown of uranium in soil, rock, and water, and can be found anywhere in the world. This radioactive gas comes up out of the ground and can seep into buildings. According to the United States Surgeon General, radon is the second leading cause of lung cancer deaths in the United States after smoking. A 2003 report from the EPA estimated that radon causes about 21,000 lung (9 comments)