In calculating Working Level, the unit of measurement for radon concentration is typically expressed in what?

The unit of measurement for radon concentration is typically expressed in picocuries per liter (pCi/L). This unit quantifies the amount of radon gas present in one liter of air. Understanding radon concentration is crucial in evaluating exposure risks, as radon is a radioactive gas that can accumulate in homes and buildings, leading to potential health hazards such as lung cancer.

In radon measurement and assessment, pCi/L is widely used in the United States and is recognized as a standard unit to communicate levels of radon. It provides a clear and understandable figure for both professionals and the public regarding indoor air quality and radon levels.

Other units mentioned, like Bq/m³, are used in different contexts but are less common in the U.S. for direct communication of radon levels in indoor air. WL (Working Level) specifically refers to the concentration of radon decay products rather than radon itself, while uSv/h relates to the measurement of radiation dose rate rather than concentration of radon gas. Thus, pCi/L is the most appropriate and standardized unit for this purpose.