Akademik Veri Yönetim Sistemi
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, cilt.80, sa.5, ss.475-479, 2008 (SCI-Expanded)
After the Chernobyl nuclear accident in 1986, 14 lichen specimens collected from Trabzon and Rize in 1995 were used to detect the amount of the fallout radionuclides. In this paper, radioactivity levels in the same species from the same localities were re-detected to compare with those of 1995. According to the results of the two studies, the radioactivity levels that this paper found for 137 Cs and 40 K are significantly lower than those of 1995 ( about 5.5 - 127 folds for Cs-137, 5-17 folds for (40) K). The level of Pb-212 was acceptably small. The highest activities of the lichen species are seen in the locality of Helvaci ( Trabzon, 100 m) and Camlihemsin ( Rize, 1850 m) while the activities are medium in Bozdogan ( Trabzon, 150 m), Kemaliye ( Trabzon, 750 m) and Camlihems, in ( Rize, 900 m). The activity values generally increase significantly depending on the altitudes. Since the measurements were performed 20 years after the Chernobyl accident in 1986, radionuclides of 134 Cs having short half-life ( 2.062 y) have not been detected. All data was obtained with a coaxial high purity Ge detector of 15% relative efficiency and resolution 1.9 keV at the 1332 keV gamma of (60) Co ( Canberra, GC 1519 model).