What is the minimum duration for a long radon test?

A long-term radon test is typically conducted over a minimum period of 90 days, with the standard duration being at least 91 days. This extended testing period is essential because radon levels can vary significantly based on seasonal changes, weather conditions, and other factors. A longer test duration allows for a more accurate representation of the average radon concentration in the environment, as it captures fluctuations over time.

Shorter testing durations, such as 30 or 60 days, may not adequately reflect the true average radon levels and could lead to either false positives or negatives. These shorter tests are typically classified as short-term tests and are not sufficient for making definitive assessments of radon exposure.

Therefore, selecting a testing duration of 91 days aligns with the established guidelines for accurately gauging radon levels, ensuring that the results are robust and reliable for evaluating potential health risks associated with radon exposure.