No abstract

The activity concentrations of (226)Ra, (232)Th and (40)K in twelve different domestic and imported tiling rocks (granites) used as building materials in Turkey were determined by employing high-resolution γ-ray spectrometry. The samples were evaluated to assess the radiation hazard for people by comparing the results with the control values recommended by the European Commission. The measured activity concentrations ranged from 7 to 136 Bq kg(-1), 9 to 138 Bq kg(-1) and 541 to 1277 Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. Applying dose criteria recommended by the European Commission([15]), two of the samples showed higher Ra(eq) values than the limit dose of 370 Bq kg(-1), equivalent to a γ-dose of 1.5 mSv y(-1). The calculated gamma-index (I(γ)) values for all the 12 samples were lower than the recommended dose criterion. In some of the samples; however, the H(ex) and H(in) values were more than unity. The absorbed dose rates (D) for all the samples, except for four samples, were located within the range values recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)([3]). Annual effective dose (AED) values, except for one sample, were greater than the world average value of UNSCEAR([3]).

To evaluate the effect of radionuclide emission on the environment from Yatagan, Yenikoy and Kemerkoy coal-fired power plants which are located in southwestern Anatolia of Turkey, the concentrations of natural radionuclides such as (226)Ra, (232)Th and (40)K in coal, bottom ash and fly ash samples, have been measured, as well as the concentration of the same radionuclides in surface soils. The dose rate arises from the total radioactivity content of soil that the people living by the power plants are exposed to be assessed additionally. The average activity concentrations of (226)Ra for Yatagan CPP is 80 ± 22 Bq kg(-1) ranging from 56 to 131 Bq kg(-1), for Yenikoy CPP is 138 ± 20 Bq kg(-1) ranging from 115 to 189 Bq kg(-1), for Kemerkoy CPP is 238 ± 80 Bq kg(-1) ranging from 134 to 356 Bq kg(-1) in coal; average activity concentrations of (226)Ra in fly ash and in bottom ash for above-mentioned power plants are 334 ± 60 Bq kg(-1) ranging from 291 to 481 Bq kg(-1), 461 ± 33 Bq kg(-1) ranging from 398 to 511 Bq kg(-1), 815 ± 254 Bq kg(-1) ranging from 316 to 1260 Bq kg(-1), 276 ± 51 Bq kg(-1) ranging from 222 to 349 Bq kg(-1), 285 ± 69 Bq kg(-1) ranging from 213 to 409 Bq kg(-1), 743 ± 234 Bq kg(-1) ranging from 366 to 1098 Bq kg(-1), respectively. The radionuclides activity concentrations of surface soil in the vicinity of coal-fired power plants are 32 ± 9 Bq kg(-1) (18-53 Bq kg(-1)) for (226)Ra, 37 ± 16 Bq kg(-1) (17-89 Bq kg(-1)) for (232)Th, 455 ± 165 Bq kg(-1) (203-794 Bq kg(-1)) for (40)K relevant to Yatagan CPP; 42 ± 30 Bq kg(-1) (9-168 Bq kg(-1)) for (226)Ra, 32 ± 14 Bq kg(-1) (6-74 Bq kg(-1)) for (232)Th, 365 ± 151 Bq kg(-1) (117-937 Bq kg(-1)) for (40)K relevant to Yenikoy and Kemerkoy CPP. As a result, average dose rates in the vicinity of coal-fired power plants have been calculated to be 56 ± 16 nGy h(-1) ranging from 30 to 100 nGy h(-1) for Yatagan CPP, 54 ± 22 nGy h(-1) ranging from 15 to 126 nGy h(-1) for Yenikoy and Kemerkoy CPP. To sum up, the natural radionuclide activity concentrations of burnt coal and ashes thrown out from these three power plants are quite high relative to the world average UNSCEAR[1] data. In addition, the average (226)Ra, (232)Th and (40)K activity concentration values of surface soil samples and the calculated gamma dose rates in the vicinity of power plants were located within the worldwide intervals reported by UNSCEAR,[30] with some local differences.

In this study, epiphytic lichen Xanthoria parietina was applied as the biomonitor of air pollution to determine the environmental influence in the vicinity of Soma coal-fired power plant. Thalli of lichen Xanthoria parietina growing on olive, oak and poplar trees were collected with their substrate in 2004-2006. They were taken from 44 different stations located in 3×3 km grids within an area of 30 km in diameter around the Soma power plant near the town of Soma. Lichen samples were analyzed by using the ICP-MS for As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Se, Th, U, V and Zn elements and their concentrations were mapped. The sample analyses results were evaluated by using the statistical software (SPSS 11). Average element contents of samples were, in descending order, Fe > Zn > V > Pb > Cr > Cu > Ni > As > Co > U > Th > Se > Cd > Hg. Results obtained in the current study were generally found to be higher than the data reported in literature although some lower values exist for Cd, Co, Hg, Ni, Pb elements. The most polluted areas were found to be those in the vicinity of the coal-fired power plant, particularly along the direction of predominant wind and in the corridor which runs from west to southeast direction due to topographic conditions. We believe that this research which is conducted around a coal-fired power plant will shed light on future research on pollution.

In this study, the natural radioactivity level and its effects on the environment of Lake Van, which is the largest lake in Turkey, were investigated extensively. Initially, 254 soil samples have been collected from the districts (Tusba, Edremit, Gevas, Tatvan, Ahlat, Adilcevaz, Ercis) located around the coastline of Lake Van in eastern Turkey. A Na(TI) detector was used to detect activity concentrations of radium (226Ra), thorium (232Th) and potassium (40K) in each collected soil sample. The obtained average results were compared with available data from Turkey and international data base. The average activity in soil samples was measured as 28.0 ± 3.7–43.6 ± 2.2 Bq/kg for 226Ra, 27.3 ± 4.1–55.4 ± 4.8 Bq/kg for 232Th and 377 ± 42– 706 ± 40 Bq/kg for 40K. It was observed that the average concentrations of 226Ra, 232Th, 40K (43.6 ± 2.2, 55.4 ± 4.8, 706 ± 40 Bq/kg, respectively) for Tatvan district and (37.0 ± 3.5, 51.4 ± 4.2, 479 ± 41 Bq/kg, respectively) for Ahlat district were higher than both national and international average value. In addition, radiological effect parameters originating from terrestrial natural radionuclides for the study area; gamma dose rate (Dout), annual effective dose equivalent (AEDE), and lifetime cancer development probability (LCR) were calculated. The Dout, AEDE, LCR (83.0 ± 3.9 nGy/h, 0.102 ± 0.005 mSv/y, 0.36 ± 0.02 x 10–3, respectively) parameters in Tatvan district were found to be above the international allowable value.