Radon is a naturally occurring gas found in our environment. It is present in almost all rock, soil and water found on earth. Radon itself is a harmless, chemically inert gas. What is dangerous about radon is that it breaks down into polonium & lead particles. These are chemically very active as well as radioactive.
Radon is Toxic
Radon particles cause lung cancer, and are a threat to health because they tend to collect in homes, sometimes to very high concentrations. Radon is the second most frequent cause of lung cancer, after cigarette smoking. Radon is estimated to cause about 21,000 lung cancer deaths per year .Radon is the largest source of exposure to naturally occurring radiation.