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ABSTRACT

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.

Despite the different origins, the concentrations of both the 7Be and the long.livedIran. J. Radiat. Res., 2005 2 (4): 211-213

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Background: Measurement of gross , gross activities, and cosmogenic beryllium-7 (7Be) concentrations were made both daily and weekly during the years 2001- 2004 from samples of atmospheric aerosols filtered from the air at Tehran Nuclear Research Center (35 41' N) and Zahedan (28 29' N). Materials and Methods: Weekly aerosol samples were collected with the high-volume air samplers on cellulose filters to determine the 7Be contents of samples, using a semiconductor gamma spectrometer. Airborne dust samples were collected on daily basis on fiber glass filters and used to determine the gross and gross activities with automatic beta analyzer and a ZnS(Ag) counter, respectively. In this study, the concentration and meteorological data were used to determine models for gross , gross and 7Be. Results: The air concentrations of gross and gross activities and 7Be concentrations displayed lognormal distributions during the study period. Both and 7Be had maximum activity concentrations during warm mid-year months. Conclusion: The models can be used to estimate the part of the trend in gross and in 7Be levels that can be accounted for by-trends in local meteorology. There has been a satisfactory agreement between the results of the model and the measurements.