The Radon-222 Concentration in the Atmospheres of Mines As a Function of the Barometric Pressure

Investigations in three European mines showed that the radon content of the atmosphere in the mines rises as the barometric pressure drops and decreases when the pressure rises or when it remains constant. It is shown how to calculate supply and removal of radon. The supply consists of a permanent and a variable component. The permanent supply comes from the surface of the rock and depends on its Ra 226 content and its nature. The variable supply originates from within the rock and is a function of the suction effect of decreasing barometric pressure, but of course also depends on the nature (e.g. porosity and fissures) of the rock. The radon removal depends on the natural and artificial ventilation rates, apart from the natural radioactive decay. Such calculations can be useful in order to determine the ventilation requirements, thus permitting regulation according to the variation of barometric pressure.