Whether your home is old or new, radon can be present. Homes with underground spaces frequently occupied with people are usually the primary concern. You cannot see, smell or taste this radioactive gas but you can test for it. Radon exposure has no immediate symptoms. The U.S. Environmental Protection Agency (EPA) estimates that 21,000 radon-related lung cancer deaths occur each year, about 2,900 of these deaths occur among people who never smoked.
Radon comes from uranium in the ground and can naturally move inside your home. During the winter months, tightly sealed doors and windows limit the amount of fresh air brought inside your house. The EPA estimates that nearly one out of fifteen homes in the U.S. has unsafe radon levels.
Testing for radon is easy with do-it-yourself kits sold at home improvement stores, online, or some government offices may provide them at no cost. Short-term test kits (2-3 day test) are used to get a preliminary idea of radon levels. The long-term test kits are for tests lasting 3-12 months. Please read and closely follow the directions for the kit. After use, these test kits must be sent to a laboratory for analysis and within a few weeks, you should receive the results.
The amount of radon or activity of radon is reported in units of picocuries (pCi) per volume (in liters) of air. The EPA has set an action limit of 4 pCi per liter of air (pCi/L). Average indoor radon levels are about 1.3 pCi/L. Radon levels normally found outside are about 0.4 pCi/L. Generally, the higher the radon level, the more quickly the EPA suggests taking action.
Radon Concentration (pCi/L) and Recommended Actions:
0 to < 4: No action required
4 to < 8: Mitigate within 5 years
8 to < 20: Mitigate within 1 to 4 years
20 to 200: Mitigate within 1 month or move the occupant
Source: Public Works Technical Bulletin 200-1-144: 30 October 2014 based on the EPA action levels
The main factors affecting radon exposure are geography, where you spend your time indoors, and indoor air flow. The EPA radon map can be accessed at: https://www.epa.gov/radon/find-information-about-local-radon-zones-and-state-contact-information#radonmap. Because you typically spend most of your time at home and radon accumulates in buildings, inside is where you are likely to have the most exposure. Where you spend your time indoors is important because higher concentrations occur where the radon enters a building (e.g., basements). Controlling the air flow in your home with good ventilation or by preventing radon from entering your home will reduce your exposure.
Some quick fixes are economically feasible such as sealing gaps and cracks in underground walls and foundations. Common remediation methods include preventing the radon from entering, venting the radon to the outside, or possibly opening a window. Consult with a qualified professional for the best choice for your home if necessary. Your state radon office is a good place to start for names of qualified professionals or check the "Consumer's Guide to Radon Reduction" available from the EPA Web site https://www.epa.gov/radon for more information about testing your home for radon.