Gross alpha, gross beta activities and Be-7 concentrations in surface air:analysis of their variations and prediction model

Measurements of gross alpha, gross beta activities and cosmogenic beryllium -7 (Be-7) concentrations were made each week during the years 1992, 1993, 1 994 and 1995 from samples of atmospheric aerosols filtered from the air. Th e data are sufficiently numerous to allow us to examine variations in time and through these measurements we have established several parameters that should be of importance in understanding any trends in radionuclides concen trations in the atmosphere. The weekly variation is discussed in relation t o various meteorological factors. Seasonal variation of Be-7 concentration in the atmosphere was measured and there was a tendency for a maximum in th e spring and summer and a minimum in fail and winter. It can be said for th is radionuclide that our results showed a prevailing influence of weekly av erage of the daily maximum temperature. In this work, the data on concentra tions and meteorological data have been made use of in order to determine a model for gross alpha, gross beta and Be-7, respectively. The model can be used to estimate that part of the trend in gross alpha and gross beta acti vities and in Be-7 levels that can be accounted For by trends in local mete orology. A. satisfactory agreement between the results of the model and the measurements was highlighted. (C) 1999 Elsevier Science Ltd. All rights re served.