title: Aerosol particle size distribution of atmospheric lead-210 in northern Finland.
abstract: Size-segregated aerosol samples were collected with a high-volume 6-stage cascade impactor at Sodankylä, Finland, 100 km north of the Arctic Circle. The210Pb content of the samples were determined with radiochemical separation of in-grown210Po followed by alpha spectrometry. Most of the210Pb activity was incorporated in accumulation mode aerosol particles. The activity median aerodynamic diameter (AMAD) ranged from 0.53 μm to 0.98 μm 38-61 per cent of210Pb activity was found to be associated with aerosol particles smaller than 0.69 μm. A slight downward tendency of210Pb activity median aerodynamic diameter was observed as a function of increasing210Pb activity concentration. This is related to the continental origin of airborne210Pb on one hand, and various aerosol particle growth processes on the other hand. Also a clear tendency towards a higher7Be/210Pb activity ratio as a function of increasing aerosol particle diameter was observed. This, in turn, reflects the different origin of210Pb, exhalation of222Rn from the soil into the air, and7Be, formation by cosmic radiation in the upper troposphere and the stratosphere.
authors.affiliation: Finnish Meteorological Institute, Observation Services, P.O.Box 503, FI-00101 Helsinki, Finland. Electronic address: jussi.paatero@fmi.fi.
authors.forename: Jussi
authors.initials: J
authors.lastname: Paatero
authors.affiliation: Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki, Greece. Electronic address: anta@auth.gr.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ioannidou
authors.affiliation: University of Helsinki, Laboratory of Radiochemistry, University of Helsinki, P.O.Box 55, FI-00014, Finland. Electronic address: jussi.ikonen@helsinki.fi.
authors.forename: Jussi
authors.initials: J
authors.lastname: Ikonen
authors.affiliation: University of Helsinki, Laboratory of Radiochemistry, University of Helsinki, P.O.Box 55, FI-00014, Finland. Electronic address: jukka.lehto@helsinki.fi.
authors.forename: Jukka
authors.initials: J
authors.lastname: Lehto
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry*; D005387:Finland; D007856:Lead Radioisotopes / Q000032:analysis*; D010316:Particle Size; D011834:Radiation Monitoring
chemical_list: D000336:Aerosols; D000396:Air Pollutants, Radioactive; D007856:Lead Radioisotopes