Radiometric analysis of volcanic tuff stones used as ornamental and structural building materials in Turkey and evaluation of radiological risk

Volcanic tuff stones are widely used to coat the interior and exterior surfaces of buildings for ornamental purposes in the construction industry in Turkey, and are also used as structural material in the construction of masonry buildings, especially in the Cappadocia region, which is a popular tourist destination. In this study, seventy-six volcanic tuff stone samples collected from different quarries located in different geographical regions in Turkey were surveyed for radiometric analysis, and the radiological risk to human health caused by ionizing radiation from natural radionuclides in the volcanic tuff stone samples was evaluated. The activity concentrations of 238U, 232Th, 226Ra and 40K analyzed in volcanic tuff stone samples were very variable, ranging from 3 to 389, 8 to 401, 2 to 263 and 99 to 2107 Bq kg-1, respectively. The emanation coefficient and mass exhalation rate of 222Rn measured for the volcanic tuff samples ranged from 2 to 68% with an average of 34%, and 1 to 194 μBq kg-1 s-1 with an average of 43 μBq kg-1 s-1, respectively. The external (gamma) and internal (alpha) hazard indices, indoor absorbed gamma dose rate and the corresponding annual effective dose were estimated to evaluate the potential radiological risk to human health. The results showed that all of the surveyed volcanic tuff stone samples can be used as covering building materials for ornamental or insulating covering purposes. However, the use of some volcanic tuff stone samples as structural building materials should be restricted

Natural and fallout radioactivity levels and radiation hazard evaluation in soil samples

The present study aims to obtain the baseline data on natural and fallout radioactivity and to evaluate radiation hazards caused by ionizing radiation emitted from 226Ra, 232Th, 222Rn, 40K and 137Cs in surface soil samples collected from Mersin province and Akkuyu nuclear power plant region. The activity concentrations of 226Ra, 232Th, 40K and 137Cs were measured using a gamma spectrometer with HPGe detector. The activity concentrations of 226Ra, 232Th, 40K and 137Cs varied from 14.1 ± 0.7 to 65.4 ± 2.9, 12.0 ± 0.8–51.7 ± 2.1, 172.2 ± 15.8–511.1 ± 37.8 and <MDA to 86.2 ± 1.4 Bq kg-1, respectively. The average concentrations of radon in soil and air were estimated as 23.9 kBq m-3 and 76 Bq m-3. The radiological parameters such as absorbed gamma dose rate in outdoor air (DRout), annual effective dose rate from external exposure (EExt), annual effective dose rate from inhalation of radon (EInh) and lifetime cancer risk (LTCR) were calculated to evaluate radiological hazards. The average values of DRout, EExt, EInh and LTCR were found to be 51 nGy h-1, 62 µSv year-1, 715 µSv year-1 and 2.2 × 10-4, respectively. © 2016, Springer-Verlag Berlin Heidelberg

Determination of tritium activity concentration in natural water samples

This study aims to measure tritium activity concentrations in tap, well, and spring water samples from Mersin province in Turkey using a liquid scintillation counting (LSC) system and to evaluate the corresponding radiological hazards due to the ingestion of water samples. The tritium activity concentrations measured in the water samples varied from < 1.9 (detection limit) to 14.1 ± 1.0 Bq L-1 (119.5 ± 8.5 TU) with an average of 6.2 ± 0.6 Bq L-1 (52.5 ± 5.4 TU). The tritium activities in the water samples were significantly lower than the limit of 100 Bq L-1 for water intended for human consumption. The annual effective doses estimated for different age groups of the members of the public due to the intake of the tritium varied from 0.009 to 0.185 µSv y-1. © 2017 Taylor & Francis