Study of radioactive contamination of Eastern Poland

Studies of the contamination of soils of Eastern Poland with natural and artificial radionuclides lead to a conclusion that human activities have caused a visible increase of contamination with natural radionuclides. The fallout from ash from coal combustion is the main source. This factor also causes the irregular distribution of the radionuclides over the studied area. This effect is enhanced due to different sorption properties of the soils. The main radionuclide defining the radioactivity of the soils of eastern Poland is K-40 the contribution of which ranges from 55 to 70 and even 75% of the total radiodetivity. Some areas show an elevated concentration of Ra-226, Pb-214, Bi-214 and TI-208, higher than their natural contents in soils. After 1986 the contamination with Cs-137 and Cs-134 ranged from 0.5 to 10% of the total contents of radionuclides. The presence of cesium is chiefly due to the Chernobyl power plant accident.