Natural radionuclides and 137Cs in moss and lichen in eastern Serbia

• Published in: Nuclear Technology and Radiation Protection Vol. 27; no. 1; pp. 44 - 51
• Main Authors: Cuculovic, Ana, Popovic, Dragana, Cuculovic, Rodoljub, Ajtic, Jelena
• Format: Journal Article
• Language: English
• Published: VINCA Institute of Nuclear Sciences 2012
• Subjects: Eastern Serbia; lichen; moss; radionuclides
• ISSN: 1451-3994; 1452-8185
• DOI: 10.2298/NTRP1201044C

The paper presents the results of radionuclides determination in moss (Homolothecium sp., Hypnum Cupressiforme sp., and Brachythecium sp.) and lichen (Cladonia sp.) sampled in the region of Eastern Serbia during 1996-2010. The activities in moss are in the range of 100-500 Bq/kg d. w. for 40K, and 5-50 Bq/kg d. w. for 226Ra and 232Th, while the ?soil-to-moss? transfer factors are 0.45 for 40K, 3 for 226Ra, and 0.3 for 232Th. The spatial distribution of the 137Cs activities is highly non-uniform; some values reach 500 Bq/kg d. w., with less than 10% of the samples, mainly the ones taken prior to 2000, with the activity above 1000 Bq/kg d. w. The variations in the content of natural radionuclides among the moss species are not significant. The frequency pattern of the activities of natural radionuclides in lichen is similar to the one in moss, but the activities in lichen are to some extent lower. The mean activity of 137Cs in lichen is below 400 Bq/kg d. w. The mean activities of 7Be in moss and lichen sampled in 2006 and 2008 are in the range of 41-122 Bq/kg d. w., with pronounced variations between the sampling sites. U radu su predstavljeni rezultati odredjivanja radionuklida u mahovinama (Homolothecium sp., Hypnum Cupressiforme sp. i Brachythecium sp.) i lisaju (Cladonia sp.) koji su uzorkovani u regionu istocne Srbije tokom 1996-2010 godine. Aktivnosti u mahovinama iznose 100-500 Bq/kg suve materije za 40K, i 5-50 Bq/kg suve materije za 226Ra i 232Th. Dobijeni su transfer faktori ?zemljiste-mahovina?: 0.45 za 40K, 3 za 226Ra i 0.3 i 232Th. Prostorna distribucija aktivnosti 137Cs je izrazito neuniformna; manje od 10% uzoraka, uglavnom onih pre 2000. godine, ima aktivnost vecu od 1000 Bq/kg suve materije. Varijacije sadrzaja prirodnih radionuklida u mahovinama nisu znacajne. Frekvencione krive aktivnosti prirodnih radionuklida u lisaju slicne su onima u mahovinama, dok su aktivnosti izmerene u lisaju nesto nize. Srednja aktivnost 137Cs u lisaju manja je od 400 Bq/kg suve materije. Srednje aktivnosti 7Be u mahovinama i lisaju, koji su uzorkovani tokom 2006. i 2008. godine, iznose 41-122 Bq/kg suve materije, sa izrazenim varijacijama izmedju lokacija. PR Projekat Ministarstva nauke Republike Srbije, br. 43009: New Technologies in the Environmental protection i br. 43007: Studying climate change and its influence on the environment: Impacts, adaptation and mitigation