| NUKLEONIKA 2002, 47(2):87-91
DETERMINATION OF RADIOACTIVITY IN AIR FILTERS BY ALPHA
AND GAMMA SPECTROMETRY
Henryk Bem1, Ewa M. Bem2, Małgorzata Krzemińska1, Monika Ostrowska1
1 Institute of Applied Radiation Chemistry, Technical University of Lodz,
116 Zeromskiego Str., 90-924 Lodz, Poland
2 Department of Environmental Engineering, Technical University of Lodz,
213 Wolczanska Str., 93-005 Lodz, Poland
Combination of alpha and gamma spectrometry for air filtres measurement allows a simple determination of all short-lived 222Rn and 220Rn daughters as well as cosmogenic 7Be and anthropogenic 137Cs in the air. Solid radionuclides in the atmosphere, attached to aerosol particles, were collected on filters of High Volume Air Sampler. After the desired collection period, the activity of deposited radionuclides was measured by g-spectrometry for 7Be, 212Pb, 212Bi, 214Pb, 214Bi and by a-spectrometry for 212Po, 214Po, and 218Po. Spectrometric methods do not require additional sample preparation and allow one to find aerosol activity by a simple filter measurement. A special measurement and calculation procedure was applied in the case of radionuclides from the uranium and thorium series. A technique of liquid scintillation counting (LSC) was used to determine the activity of the long-lived radon daughters 210Pb, 210Bi, 210Po after leaching into HCL solution and a two-step pre-concentration. Simultaneous determination of 210Pb and 210Bi enables one to find aerosol residence times.
Close X |