A Review of Radon Equilibrium Factors in Underground Mines, Caves, and Thermal SPAS.

Radon equilibrium factorF(eq)is an important factor in radon progeny dose assessment. A review of published measurements ofF(eq)shows a range of values from 0.1 to 1.0 reported in studies from more than 26 countries measured in 173 underground mines, and 136 show caves, tourist mines, and thermal spas. The average values ofF(eq)are 0.38 in underground mines and 0.39 for show caves, tourist mines, and thermal spas. The wide range ofF(eq)in those special workplaces suggests that location-, environment-, and operation-specific values are more appropriate than a recommended average value in the calculation of lung bronchial dose. This is especially important in mines or other typically high radon exposure locations becauseF(eq)can be used for recording an individual's occupational radon exposure or dose.