Radon is a gas produced by the radioactive decay of the element radium. Radon is the number one cause of lung cancer among non-smokers, responsible for 21,000 lung cancer deaths annually, the risk can be 9X greater for smokers. The only way to know if your home has elevated Radon levels is to hire a professional trained and licensed in Radon Gas testing. The cost of Radon testing varies, so you might need to find out what the cost in your area is.
Radioactivity is measured in picocuries (pCi) per liter of air (pCi/L). The Environmental Protection Agency (EPA) recommends that the home should be fixed (radon mitigation) at a level 4 piC/L and above. A 1,000-square-foot house with 4 piC/L has nearly 2 million radon atoms decaying inside it every minute. The average concentration of Radon in outdoor air is .4 piC/L. There does not seem to be a pattern as to why some homes have elevated Radon. Take two similar homes in the same neighborhood, one may be 2 piC/L and the other 20 piC/L. If your current home or a home you are going to purchase has a mitigation system, do not assume that it is working properly. Testing prior to purchase and every couple of years thereafter would be prudent.
Radon testing is quite simple. The test is conducted at the lowest livable level. Closed building conditions need to be maintained for 12 hours prior to and during the 48-hour short-term test. All windows and doors are to be closed, doors may be used normally. No interior/exterior air exchange systems are to be used. The dryer and range hood may be used moderately while fireplaces/woodstoves may not be used at all. Window A/C’s may be used in the recirculate mode only. The main HVAC system should be operated normally.
There are several methods used today to test for radon. Charcoal canisters are widely used and are accurate in ideal conditions. However, they can be easily manipulated by throwing a towel over them or simply taking them all outside.