Gross beta activities and Beryllium-7 concentrations in surface air

Background: were made each week during year 2002 from samples of atmospheric aerosols filtered from the air at Tehran Nuclear Research Center. Measurement of gross beta activities and cosmogenic Beryllium-7 concentrations Materials and Methods sampler at the Nuclear Research Center meteorological station in Tehran (40 contents of samples were determined with semiconductor gamma spectrometry. The long-lived beta activity, i.e. total beta activity measured four days after the end of sampling (after decay of : The aerosol samples were collected weekly with high-volume airo 35. N). The 7Be 220 The long-lived beta activity consists mainly of amount of artificial radionuclides in the air is negligible. Rn progeny and short-lived 220Rn progeny), was assessed with an automatic beta analyzer.210Bi, the daughter nuclide of 210Pb, as the Results: lognormal distribution during the study period 2002. The arithmetic mean of annual concentrations of The air concentrations of both the 7Be and the long-lived beta activity displayed a7Be and 210 Pb was 6.30 and 0.50 mBqm-3, respectively . Conclusion: beta activities are partially correlated. Both have maximum concentrations during warm mid-year months.