Outdoor ~(222)Rn-concentrations in Germany - part 1 - natural background

摘要

To determine the natural radiation exposure due to outdoor radon (~(222)Rn) and its short-lived decay products in Germany, the Federal Office for Radiation Protection (BfS) conducted a measuring programme over three years. The annual mean radon concentration at 1.5 m above ground level was measured with solid-state track etch detectors at 173 measuring points in an even grid with a grid length of approx. 50 km. Furthermore, annual mean values of the equilibrium-equivalent radon concentration (EEC) and the equilibrium factor were estimated on the basis of the activity concentrations of ~(214)Pb and ~(214)Bi measured at 27 stations of the German Meteorological Service (DWD). Our study yielded a spatial mean outdoor radon concentration for Germany of 9 ± 1 Bq m~(-3) (median: 8 (-0.5/+1.0) Bq m~(-3)), with regional means varying from 4.5 Bq m~(-3) in Hamburg to 14 Bq m~(-3) in Bavaria. The determined EEC are in a range from 1.4 to 11 Bq m~(-3).