Short term tests remain in the house for 2-90 days. For this reason they are the fastest method of determining radon concentrations. Charcoal canisters, electret ion chambers, and continuous monitors are the most common types of testing equipment.
Long term tests are conducted in a time period exceeding 90 days. Alpha Track and electret test are the most common types. Though this type of testing takes more time to gather information, it is also more likely to give you a more accurate result
Radon is measured in picocuries per liter of air (pCi/L), and this measurement indicates the concentration of radon gas in the home being tested. The Environmental Protection Agency recommends that homes with a level of 4 pCi/L or higher should have mitigation systems installed to reduce the high levels of radon. As the nation's second leading cause of lung cancer, radon is estimated to cause 22,000 deaths per year. That is why a radon mitigation system is a must for homes with high levels of radon.