Whether your home is old or new, radon can be present. Homes with underground spaces frequently occupied with people are usually the primary concern. Humans cannot see, smell or taste this radioactive gas but they can test for it. Radon exposure has no immediate symptoms. The U.S. Environmental Protection Agency 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 a home. During the winter months, tightly sealed doors and windows limit the amount of fresh air brought inside a 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, and some government offices may provide them at no cost. Short-term test kits (2 to 3 day test) are used to get a preliminary idea of radon levels. The longterm test kits are for tests lasting three to 12 months.
Testers should 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, testers 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.
The main factors affecting radon exposure are geography, where someone spends 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 people typically spend most of their time at home and radon accumulates in buildings, inside is where they are likely to have the most exposure. Where people spend time indoors is important because higher concentrations occur where the radon enters a building (e.g., basements). Controlling the air flow in the home using good ventilation or by preventing radon from entering your home will reduce 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, if necessary.
The 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 homes for radon.
Radon concentration (pCi/L) and recommended actions:
20 to 200: Mitigate within one month or move the occupant
Source: Public Works Technical Bulletin 200-1-144: Oct. 30, 2014 based on the EPA action levels