Radioactivity measurements in epiphytic lichens of Uludaǧ Mountain in Western Anatolia

Abstract

Activity concentrations of gross-β, naturally occurring 226 Ra, 232 Th, 210 Pb, 7 Be and anthropogenic 137 Cs in epiphytic lichens collected from Uludaǧ Mountain are presented and discussed with the aim of evaluating potential usability of lichens as a biomonitor. The activity concentrations of gross-β, 137 Cs, 40 K, 226 Ra, 232 Th, 210 Pb and 7 Be in the lichen samples were found to be in the range of 177-707, 4.05-94.26, 86-211, below detection limit (BDL) - 19.2, BDL - 14.0, 229-872, and 72.1-220.7 Bq kg -1 in dry weight, respectively. 137 Cs content in collected epiphytic lichens was in descending order: Parmelia sulcata > Lobaria pulmonaria > Pseudevernia furfuracea > Usnea filipendula. The best biomonitor for 137 Cs among the lichen species used in this study was determined as Parmelia sulcata. Pearson's correlation coefficient was calculated between 137 Cs and 40 K activity concentrations using a statistical package program (SPSS ver. 17.0) and a negative correlation value (R = -0,323, p = 0,222) was obtained. The highest 226 Ra and 232 Th activity concentrations were found in Boǧazova YaylasI which has a geological structure including granitic rocks. It was found that 137 Cs and 7 Be activity concentrations in species demonstrated an inverse behaviour. The effect of mean annual precipitation and temperature on 7 Be activity concentration was determined using multi regression analysis. Also, correlations between the 137 Cs and 7 Be, and 40 K and 7 Be were investigated. © 2012 Akadémiai Kiadó, Budapest, Hungary.