Radon, by its own action and by its interaction with cigarette smoking, is considered to be the second leading cause of lung cancer in the U.S. today. Radon is a radioactive gas that is found in the earth's rock and soil and is formed by the natural breakdown of radium, which is a radioactive product of decaying uranium. It is estimated that 15,000 American die each year from residential radon induced lung cancer. Radon problems have been identified in every state. The EPA estimates that nearly 1 out of every 15 homes in the U.S. has indoor radon levels at or above the EPA's recommended action guideline level of four picocuries per liter of air on a yearly average.
Radon can be a problem in schools and workplaces, too.
Because radon is invisible and odorless, the only way to determine if you are being exposed to the gas is by measuring radon levels. In addition, exposure to radon, in combination with cigarette smoking, significantly increases the risk of lung cancer. Therefore, for smokers, exposure to radon is an even greater health risk. Asbestos is perhaps the best known of the industrial substances associated with lung cancer, but there are many cancer-causing substances that people may deal with at work. These include asbestos,uranium, arsenic, certain petroleum products, and others.