Atmospheric deposition patterns of ~(210)Pb and ~7Be in Cienfuegos, Cuba

摘要

The radiometric composition of bulk deposition samples, collected monthly for one year, February 2010 until January 2011, at a site located in Cienfuegos (22° 03′ N, 80° 29′ W) (Cuba), are analysed in this paper. Measurement of ~7Be and ~(210)Pb activity concentrations were carried out in 12 bulk deposition samples. The atmospheric deposition fluxes of ~7Be and ~(210)Pb are in the range of 13.2-132 and 1.24-8.29 Bq m~(-2), and their mean values are: 56.6 and 3.97 Bq m~(-2), respectively. The time variations of the different radionuclide have been discussed in relation with meteorological factors and the mean values have been compared to those published in recent literature from other sites located at different latitudes. The annual average flux of ~(210)Pb and ~7Be were 47 and 700 Bq m~(-2) y~(-1), respectively. Observed seasonal variations of deposition data are explained in terms of different environmental features. The atmospheric deposition fluxes of ~7Be and ~(210)Pb were moderately well correlated with precipitation and well correlated with one another. The ~(210)Pb/~7Be ratios in the monthly depositions samples varied in the range of 0.05 -0.10 and showed a strong correlation with the number of rainy days.