Biomonitoring of 210Po and 210Pb using lichens and mosses around a uraniferous coal-fired power plant in western Turkey

In Gökova region where Yata an is located there are three major uraniferous coal-fired power plants (CPPs) and they cause some pollution in the surroundings. Studies were realized over a wide area around the coal-fired power station located at Yata an to evaluate the possible increase of natural radioactivity level due to the operation of the plant. The lichens Rhizoplaca melanophthalma, Cladonia convoluta, Cladonia pyxidata and the mosses Grimmia pulvinata, Hypnum cupressiforme were investigated for potential use as bioindicators for 210Po and 210Pb deposition. The maximum 210Po and 210Pb activities were observed around the hill close to ash stacks. The capture efficiency was the highest in one of the moss species, G. pulvinata with the activity concentration ranges of 600±19–1228±36 and 446±15–650±21 Bq kg−1 for 210Po and 210Pb, respectively. Soil samples were also collected and analysed in order to investigate any possible contamination in soil profiles due to CPPs and to determine unsupported 210Pb flux. The 210Pb and 226Ra concentrations in uncultivated soil profiles varied between 58±2 and 258±6 Bq kg−1, 50±5 and 58±5 Bq kg−1, respectively. The unsupported 210Pb inventory in the core was calculated to be 3312 Bq m−2. The corresponding annual 210Pb flux of 103 Bq m−2yr−1 is high with compare to estimates of the atmospheric flux given in literature for the same region.