BE-7 as tracer for size distribution of particulate at different locations and under different meteorological conditions

The aerosol particles in the atmosphere are liquid or solid particles, with sizes from fraction of μm to several hundreds of μm. Atmospheric aerosols may be emitted by both natural and anthropogenic sources. Airborne radionuclides that absorbed on the surface of aerosol particles form the radioactive aerosols and their behaviour is determined by the behaviour of their carrier aerosol particles. Beryllium-7 is a cosmogenic radionuclide that decays with a 53.3 day half-life: once it is formed is attached to aerosol particles, transported by winds and removed by wet and dry deposition in the troposphere. The particle composition and size distribution of radioactive aerosols and their carrier aerosol particles at a site affected by a number of factors like their source, fog and cloud droplet formation, evaporation and condensation, washout, rainout, dispersion conditions, the season of the year and the local meteorological conditions. We study the size distribution of aerosol particles at different locations during the four seasons of a year by mean the Be-7 activity. Since local meteorological conditions might affect strongly the AMAD (Activity Median Aerodynamic Diameter) of 7Be aerosols and disappear any fluctuation due to the location, all measurements under different seasons and under different environments were carried out with a parallel measurement at a reference station, thanking to that we can use two compatible 1ACFM cascade impactors.