The issue with this gas is that it is not uncommon for it to escape from soil, water, or rock and slip right through your home or business foundation. While outdoor radon disperses rapidly and is generally not a health issue, if this gas is trapped indoors, it can build up and cause serious health issues. Breathing in excess radon levels has been shown to increase people’s risk of developing lung cancer. In fact, the Environmental Protection Agency (EPA) estimates that about 21,000 people die each year from radon-related lung cancer nationally. Along with the EPA, The World Health Organization (WHO), the National Academy of Sciences, as well as the US Department of Health and Human Services have all classified radon as a known human carcinogen.