Radon is a radioactive gas which comes from the decay of naturally-occurring uranium in soil, rock and water and can get into the air you breathe. You can't see radon. You can't smell it or taste it either. But it could be a problem if it gets into your home. In fact, the Surgeon General has warned that radon is the second leading cause of lung cancer in the United States today. Only smoking causes more lung cancer deaths.
Radon can be found all over the United States. It can get into any type of buildings - homes, offices, and schools - and build up to unsafe levels. But you and your family are most likely to get your greatest exposure at home. That's where you spend most of your time.
Your family's risk of developing lung cancer from radon depends on the average annual level of radon in your home and the amount of time you spend there. The longer your exposure to radon, the greater the risk, and the risk is much greater for smokers. The amount of radon in the air is measured in "picocuries of radon per liter of air," or "pCi/l." EPA recommends that you should fix your home if the results of one long-term test or the average of two short-term tests, taken in the lowest lived-in level of the home, show radon levels of 4 pCi/lor higher. A short-term test remains in your home for two days to 90 days, whereas a long-term test remains in your home for more than 90 days. With today's technology, radon levels in most homes can be reduced to 2 pCi/l or below.
Radon gas decays into radioactive particles that can get trapped in your lungs as you breathe. As they break down further, these particles release small bursts of energy. This can damage lung tissue and lead to lung cancer over the course of your lifetime. Not everyone exposed to elevated levels of radon will develop lung cancer, and the length of time between exposure and the onset of the disease may be many years. Like other environmental pollutants, there is some uncertainty about the magnitude of radon health risks. However, we know more about radon risks than risks from most other cancer-causing substances. This is because estimates of radon risks are based on studies of lung cancer in humans (underground miners). Smoking, combined with radon, is an especially serious health risk. Your chances of getting lung cancer from radon depend mostly on: 1) how much radon is in your home; 2) the amount of time you spend in your home; and 3) whether you are a smoker or have ever smoked.