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

摘要

The significant differences in the activities of ²¹⁰Pb, ²¹⁰Bi, ²¹⁰Po and cosmogenic ⁷Be and ²²Na 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 ²²²Rn decay in the air) to the total activity concentrations of ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Po radionuclides in the urban air, plays a substantial role (up to 97% of the total activity) only in the case of ²¹⁰Po.