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

The significant differences in the activities of Pb-210, Bi-210, Po-210 and cosmogenic Be-7 and Na-22 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 A center dot 25 days) and in the lower stratosphere (103 A center dot 205 days). The relative input of the additional sources (beside of the Rn-222 decay in the air) to the total activity concentrations of Pb-210, Bi-210 and Po-210 radionuclides in the urban air, plays a substantial role (up to 97% of the total activity) only in the case of Po-210.