No abstract

The activity concentrations of (40)K, (238)U, (232)Th and (137)Cs have been measured using a gamma spectrometric method in different samples from the environment of two mountains in Serbia (altitude 1000-1100 m), during the period 2002-2007. The mountains Maljen and Tara (popular tourist destinations) are near Belgrade. On mountain Maljen, samples were taken at 4 different altitudes (200 m, 650 m, 1000 m and 1100 m), and on mountain Tara at altitudes of 1000 m and 1100 m. On mountain Maljen it was found that the level of (137)Cs activity increased with altitude in samples of soil, grass, hay and cow, sheep and goat milk. On the contrary, (40)K activity decreased with altitude in samples of soil, grass and hay. The highest activity concentrations of (137)Cs were found in bioindicators: sheep meat, venison, wild boar meat, moss and mushrooms. These results indicate that (137)Cs is present in mountain region of Serbia even 20 years after the nuclear accident in Chernobyl. Deposition of (137)Cs was almost two times higher on the Maljen mountain compared to Tara mountain. An average annual dose arising from (137)Cs was 7.4 microSv due to ingestion of cow milk and 6.3 microSv due to ingestion of mushrooms at the Maljen mountain.

By gamma spectroscopic measurement a content of natural radio-nuclides (40K, 238U, 226Ra, 232Th) and 137Cs was determined in samples of soil, alfalfa, maize and moss on six sites in the surroundings of Belgrade. Natural radionuclides in the soil were at the level characteristic for Serbia, whereas a relatively high level of activity of 137Cs (around 30 Bq kg-1) was determined. On the other hand, in plant samples mostly used as feed (such as alfalfa and maize) the concentration of natural radio-nuclide activity and 137Cs was relatively low, i.e. below the range of detection. The content of natural radio-nuclides in moss was within the standard range of values specific for Serbia. However, the activity level of 137Cs in moss gathered from the wider area around Belgrade, was high, the highest measured level being in the Avala-Zuce area (158-221 Bq kg-1). Our results show that this radio-nuclide is still present in the living environment of Belgrade even 20 years after the Chernobyl disaster, and that moss is a good indicator of living environment 137Cs contamination

The objective of this study was to evaluate the 137 Cs binding capacity of clinoptilolite.In the first in vitro experiment we investigated sorption of 137 Cs to natural and modified forms of clinoptilolite in highly acid solution,prepared to be similar to that of the gut of pigs (pH =2 3)at 37 ºC.In the second in vivo experiment 137 Cs binding to a modified form of clinoptilolite was studied in orally contaminated broiler chickens.137 Cs sorption in the high acidity solution depended on clinoptilolite concentration and varied between 30 85 %of the initial activity.In the chickens,three hours after 137 Cs administration,there was 67%and 63%lower accumulation of 137 Cs in meat and edible organs (respectively)and seven hours after 137 Cs administration,there was 69% and 49% lower accumulation of 137 Cs in meat and edible organs (respectively)compared to the controls with no clinoptilolite added in food. Natural and modified forms of clinoptilolite have been shown to high sorption efficiency towards 137 Cs ions and could be recommended as possible radiocaesium binders in domestic animals.;

No abstract