To detect radon, use long-term tests (3–7 days) or short-term tests (2–90 days) placed in high-risk areas like basements. Check certified devices from the Environmental Protection Agency (EPA) and ensure proper placement and sealing. Convert readings to picoCuries per liter (pCi/L) and compare to the EPA’s action level of 4 pCi/L.

Long-term tests are preferred because radon levels fluctuate daily, and prolonged exposure provides more accurate results. The EPA’s 2021 report found that 6.9 million U.S. homes exceed the 4 pCi/L threshold, with 1 in 15 homes at dangerous levels. Short-term tests, while quicker, may miss peaks, as shown in a 2019 study by the National Radon Safety Board, which found short-term devices underestimated levels by up to 50% in some cases. Radon is the second leading cause of lung cancer, responsible for 21,000 annual deaths in the U.S., according to the American Lung Association. The EPA recommends installing mitigation systems if levels exceed 4 pCi/L, which can reduce concentrations by 80–99%. Regular testing is critical, as EPA data indicates 38% of homes in high-risk zones remain undetected due to infrequent testing.