The hot particles in the southern districts of Belarus: distribution, composition and properties

A complex study of hot particles (HP) distribution and the dynamics of its change has been made. The investigated area is situated within 40-250 km of Chernobyl Nuclear Power Plant (NPP). It is found that HP content in soil is in the range 104 102/m2 and decreases with the distance from NPP. A general decrease in the β-activity with time (1987 - 92) has been found and it is more prominent on remote cites. Some HP migration takes place in the near-surface soil layer (10 - 25 cm). In addition, environmental desegregation is taking place and causes mechanical destruction, increasing the finest fraction of HP. Data for HP distribution in air are based on lung tissue investigations. In samples taken in 1990/92 a decrease of HP number is observed as compared to 1987 - 8 samples. A similar trend of HP number decrease with the distance is reported. Within the lungs it was more probable to detect HP in the lower lung segments. Radionuclide and elemental composition show that the relative amount of Cs is increasing with the distance as opposed to Pu. Chemical solubility in acids is reported to increase with 5% a year. It is concluded that the mechanical and chemical stability of HP deteriorate with the distance from NPP. 4 figs., 3 tabs