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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.
The results of studies of radioactive contamination of Borne Sulinowo military range is presented. Until 1991, this area was occupied by the former Soviet Army. No serious contamination with natural or artificial radionuclides has been found in the studied area. The activity of natural radionuclides such as 214Bi, 226Ra, 234Th, 224Ra, 228Ac and 214Pb in the soils ranges from 6-8 Bq/kg of soil, which is low when compared to industrial regions of Poland, where 18-36 Bq/kg of these radionuclides have been found. Also, contamination by 137Cs is considerably lower than in Eastern Poland. In about 70% of the studied samples, post-Chernobyl radiocesium contributed less than half of the total amount of this nuclide. It follows that post-Chernobyl fallout was low in the studied area. Moreover, the high level of l37Cs from global fallout in the examined samples manifests strong bonding of cesium in the surface layer of the soil.
This paper encloses results of field tests carried out on two types of organic soils. Activities of caesium, originating from global fallout as well as from the Chernobyl power plant breakdown, were measured for these two soils. Radioactive caesium is present to a depth of 40 and 70 cm, in black soil and in peat, respectively, although the highest activity was found in the topmost layers. Caesium originating from the Chernobyl accident constitutes about 70% of the total activity in the 0-10 cm layers of the soils. The vertical migration rates of caesium from both sources were also measured. In the case of peat soil the migration rate of the Chernobyl caesium as well as that from global fallout were found to be similar and amounted to 0.2 cm/year. In the case of black soil the differences were more pronounced (0.34 and 0.14 cm/year, respectively). Results of the physicochemical analysis of both tested soils are also included in this work.
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