If a room has an equilibrium ratio of 0.6 and a radon concentration of 15 pCi/L, what is its Working Level?

To find the Working Level based on the given equilibrium ratio and radon concentration, you start with the understanding of what these terms mean. The equilibrium ratio indicates the fraction of radon decay products present in relation to the parent radon concentration.

In this case, the equilibrium ratio is 0.6, and the radon concentration is 15 pCi/L. The formula to convert radon concentration to Working Level is:

Working Level (WL) = Radon Concentration (pCi/L) × Equilibrium Ratio

Applying the values in this question, we calculate:

Working Level = 15 pCi/L × 0.6 = 9 pCi/L

Since 1 WL is defined as the concentration of radon decay products in equilibrium that would result in a 1 pCi/L concentration of radon, you express the Working Level in terms of pCi/L when calculating it from radon concentration. In a converted format for Working Level, we consider it in a scale appropriate for the context, leading to results where the Working Level is expressed in a decimal form.

The calculation directly supports that the Working Level corresponds to the choice that would round appropriately based on the key unit conversions usually adopted in reference discussions surrounding radon