Indoor radon seasonal variability at different floors of buildings

Indoor radon concentrations have been measured with the α track etch integrated method in public buildings in the town of Pietramelara, north-western Campania, Southern Italy. In particular, our measurements were part of an environmental monitoring program originally aimed at assessing the range of seasonal fluctuations in indoor radon concentrations, at various floors of the studied buildings. However, subsequent analysis of the data and its comparison with the meteorological data recorded in the same period has shown an unexpected pattern at the different floors. In this report we present data suggesting that, besides the well-known medium and longterm periodicity, there could also be a differentiation in major meteorological controlling factors at the different floors of the buildings, a fact that does not appear to have been reported previously. While the lower floors proved to be markedly affected by rainfall, for the upper floors, instead, a different behaviour has been detected, which could possibly be related to global solar radiation.