To what decimal place should the results of a radon test be rounded?

The results of a radon test should be rounded to one digit after the decimal. This level of precision is appropriate for radon measurements, as it reflects the variability and uncertainty intrinsic to radon detection methods while still providing a clear and actionable reading.

Rounding to one digit after the decimal allows for a straightforward interpretation of results without overwhelming detail that may not significantly impact decision-making. In practice, radon concentrations are often reported in picocuries per liter (pCi/L), and this rounding is consistent with standard reporting practices within the field.

Providing results to one decimal place balances the need for accuracy with the practicality of understanding and communicating results effectively. Using a whole number may lead to a loss of important data, while rounding to two or more digits could complicate discussions on necessary mitigation actions.