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Determination of Lead-210 and its Progenies in Aerosol Fractions of Different Particles Sizes

Determinations of Pb in aerosol fractions of particle sizes between 0.015 — 16 μιτι have been carried out from air volumes of 35 —100 m by α-spectrometry via °Po after equilibrium has been established, i.e. one or more years later, or directly by liquid scintillation spectrometry using pulse shape analysis immediately after sample collection. In this way also the Bi/"'Pb and the "Po/Pb ratios have been obtained. Based on different models published in the literature aerosol residence times are discussed.