Natural and anthropogenic radionuclides in airborne particulate samples collected in Barcelona (Spain)

Results for naturally occurring 7Be, 210Pb, 40K, 214Bi, 214Pb, 212Pb, 228Ac and 208Tl and anthropogenic 137Cs in airborne particulate matter in the Barcelona area during the period from January 2001 to December 2005 are presented and discussed. The 212Pb and 208Tl, 214Bi and 214Pb, 7Be and 210Pb radionuclide levels showed a significant correlation with each other, with correlation coefficients of 0.99, 0.78 and 0.69, respectively, suggesting similar origin/behaviour of these radionuclides in the air. Caessium-137 and Potassium-40 were transported to the air as resuspended particle from the soil. The 7Be and 210Pb concentrations showed similar seasonal variations, with a tendency for maximum concentrations during the summer months. An inverse relationship was observed between the 7Be, 210Pb, 40K and 137Cs concentrations and weekly rainfall, indicating washout of atmospheric aerosols carrying these radionuclides.