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

Measurements of gross α, gross β activities and cosmogenic beryllium-7 (7Be) concentrations were made each week during the years 1992, 1993, 1994 and 1995 from samples of atmospheric aerosols filtered from the air. The 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 concentrations in the atmosphere. The weekly variation is discussed in relation to various meteorological factors. Seasonal variation of 7Be concentration in the atmosphere was measured and there was a tendency for a maximum in the spring and summer and a minimum in fall and winter. It can be said for this radionuclide that our results showed a prevailing influence of weekly average of the daily maximum temperature. In this work, the data on concentrations and meteorological data have been made use of in order to determine a model for gross α, gross β and 7Be, respectively. The model can be used to estimate that part of the trend in gross α and gross β activities and in 7Be levels that can be accounted for by trends in local meteorology. A satisfactory agreement between the results of the model and the measurements was highlighted