EN
The contamination of the city of Lublin by gamma emitters and contents of radionuclides in the ground layer of air were studied. A heterogeneous distribution of radiocesium was found in soils, due chiefly to the Chernobyl power plant accident The contribution of afiter-Chernobyl radiocesium to the total amount of this radioelement in the surface layer of the soil averages 85%. Compared with so-called uncontaminated areas, there is an elevated level of the natural nuclides Ra-226, Ra-224, Ac-228, Pb-212 and Bi-212 in the city. However, potassium-40, whose contribution averages about 65% of total activity, is the main gamma emitter found in Lublin soil. In grass samples, the contribution of K-40 averages as high as 85%. Substantial amounts of Ra-226 and Ra-224 were also found in grass. Radiocesium activity in grass ranges from 0.6 to 11 Bq/kg of dry matter and the transfer factor of Cs-137 from soil to grass ranges from 0.07 to 0.85. The radioactivity of the ground layer of air was as low as 1.2 — 3.4 mBq/m3.