Analysis of 7Be and 210Pb concentration and 7Be/210Pb activity ratio in ground level air in Palermo (Italy)

A series of measurements of particulate samples collected on paper filters in Palermo (Italy) during 1995–2005 has been performed to detect 210Pb air activity concentration and, along with previous similar data on 7Be, to evaluate their activity ratio. Average values for the daily activity concentrations of 7Be and 210Pb are found to be 4.7 and 0.6 mBq/m3 , respectively, 9.8 being the average activity ratio. Data confirm a seasonal behavior for both radionuclides. A correlation between 7Be and 210Pb air activity concentrations seems to exist, despite their different origins. The time behaviors of both 7Be and 210Pb air concentrations and 7Be/ 210Pb activity ratio have been compared with some meteorological parameter time series. The analysis of the data shows a weak correlation with rainfall, while no correlation can be established with other parameters. Monthly and weekly average values have been reconstructed taking into account missing data, in order to carry out homogeneous comparisons with available data from other geographical areas. Data series correlations and the frequency analysis show the importance of atmospheric transport processes and the influence of meteorological and climatic parameters (in particular rainfall) in determining the concentrations in air of both radionuclides.