Determination of the mean aerosol residence times in the atmosphere and additional (210)Po input on the base of simultaneous determination of (7)Be, (22)Na, (210)Pb, (210)Bi and (210)Po in urban air

The significant differences in the activities of (210)Pb, (210)Bi, (210)Po and cosmogenic (7)Be and (22)Na radionuclides in the urban aerosol samples collected in the summers 2010 and 2011 in the Lodz city of Poland were observed. Simultaneous measurement of these radionuclides, after a simple modification of the one compartment model, allows us to calculate both: the corrected aerosol residence times in the troposphere (1 ÷ 25 days) and in the lower stratosphere (103 ÷ 205 days). The relative input of the additional sources (beside of the (222)Rn decay in the air) to the total activity concentrations of (210)Pb, (210)Bi and (210)Po radionuclides in the urban air, plays a substantial role (up to 97% of the total activity) only in the case of (210)Po.