In the United States radon is the second leading cause of lung cancer with approximately 21,000 deaths related to radon each year. Approximately 16% of homes across the United States have an unsafe radon level above 4pCi/L. Some states and areas of the country have significantly higher and lower levels depending on their geology. Radon is an odorless gas that is formed from radioactive decay in the soil. It's present everywhere in the environment. The average outside level is below .4pCi/L so it's very low normally outside. Where radon tends to concentrate in higher levels is inside homes and buildings.
There are several methods to obtaining a radon measurement result ranging from charcoal canisters to continuous radon monitors which are the most common. Charcoal canisters are placed out and after a specific period of time are sent into a laboratory for testing. Charcoal testing takes much longer than using a continuous radon monitor as the samples have to be sent in and then there is a waiting period for the results. Continuous radon monitors take an hourly air sample and give an average level of radon based on all the hourly air samples collected. For residential real estate transactions the time period is normally 48 hours but can be longer if needed. The results are instant once the test is complete. They provide a big advantage to charcoal tests because they give an hourly level of radon and there is no waiting period for results. Also continuous radon monitors aren't affected by moisture. In addition, many continuous radon monitors often have security features, which prevent them from being moved without invalidating a test result.
Some states have licensing or certification requirements for residential radon testing. In Wisconsin there are no requirements. Make sure that whoever you hire that is measuring the radon level in your home is certified to do so by the National Radon Proficiency Program NRPP or another organization that certifies radon testing.
At Dairyland Home Inspection we perform radon measurements in Racine, Milwaukee, Kenosha, Waukesha, and Walworth counties as part of a home inspection or a home warranty inspection.