Question: are home radon tests reliable?
Answer: Findings show radon tests of less than 90 days are imprecise up to 99 percent of the time. ... A new study finds the only reliable way to measure exposure to radon gas is with a long-term testing kit, 90 or more days. Researchers placed two test kits, a short term (five-day) and long term (90-day) in the same homes.