Measurement of radioactivity levels and assessment of radioactivity hazards of soil samples in Karaman, Turkey

Radiological hazard assessment of natural radioactivity in Avcilar region, Turkey: a case of Istanbul University-Cerrahpasa Avcilar Campus

Radionuclides 226Ra, 232Th, and 40K can be found in various concentrations in the surface soil. High concentrations of radionuclides in the surface soil may cause radiological risks. This study investigated natural radioactivity levels and artificial radionuclide (137Cs) levels in the Istanbul University-Cerrahpasa, Avcilar region, Istanbul, Turkey. Radioactivity concentrations were analyzed using the gamma-ray spectrometer. The mean activity concentration of 226Ra, 232Th, 40K, and 137Cs is 28.55, 29.57, 385.72, and 3.09 Bq kg-1, respectively. Radiological parameters radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, and excess lifetime cancer risk were calculated using activity concentrations. The radiological parameters values were lower than UNSCEAR values, except for the annual gonadal dose equivalent (approximately 10% higher). There is a strong correlation between radiological parameters and radionuclides. Generally, the activities of radionuclides in the region fall within the recommended limits, thus Istanbul-Avcilar region can be considered safe for settlement.

Measurement of natural radioactivity in several sandy-loamy soil samples from Sijua, Dhanbad, India

The activity concentrations of natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in soil samples collected from Sijua Dhanbad, India were measured by using a gamma-ray spectrometer with a NaI(Tl) detector. The average activity concentration of ²²⁶Ra, ²³²Th, and ⁴⁰K was found as 60.3, 64.5 and 481.0 Bq. kg−1, respectively. Average radium equivalent activity, absorbed dose rate, outdoor dose, external hazard index and internal hazard index for the area under study is determined as 189.5 Bq. kg−1, 87.2 nGy h−1, 0.4, 0.5 and 0.6 mSv. y−1, respectively. The annual effective dose to the general public is found 0.4 mSv. y−1. This value lies well below the limit of 1 mSv. y−1. Measured values have found safe for the environment and public health of the study area.

Study on gamma ray shielding performance of concretes doped with natural sepiolite mineral

Gamma ray attenuation coefficients for various concrete types containing natural sepiolite mineral and B4C have been experimentally investigated at different gamma energies. In order to obtain the gamma rays, the four radioactive point-isotropic sources 133Ba, 137Cs, 60Co and 22Na which energies ranged from 80.9 to 1332.5 keV have been utilized. The measurements have been carried out by using HPGe detector and MCA equipped with a personal computer. The morphological structure and elemental compositions of the concretes have been measured with scanning electron microscope (SEM) and energy-dispersive X-ray (EDX) analyses. Linear attenuation coefficient (μ), mass attenuation coefficient (μ m ), half value layer (HVL) and mean free path (MFP) have been calculated for all concretes. The obtained results have been compared to the other materials such as Pb and Al.

Computation of gamma radioactivity of natural rocks in the vicinity of Antalya province and its effect on health

The aim of this study is to determine uranium (238U), potassium (40K) and thorium (232Th) in the radioactive elements by measuring the natural rocks in the vicinity of Antalya province by using High-purity Germanium (HPGe) Detector with gamma spectrometry 69. At the end of the measurements, total absorbed dose rates of the rock samples have been found to be within the normal range of values between 3.10 nGy/h and 117.35 nGy/h. While the minimum value of Raeq has been determined to be 6.36 Bq/kg at sample S8, the maximum value has been determined as 250.15 Bq/kg at sample S4. All of the values obtained at the end of the study have been determined to be lower than the maximum Raeq value (370 Bq/kg) and the limit values for industrial products which ranges between 370 – 740 Bq/kg. ARa, ATh and AK; 232Th, 40K and 226Ra of radionuclides are the activity concentrations in terms of Bq/kg. The hex value should be less than 1. The value is based on the upper limit of Raeq (370 Bq/kg). All of the results obtained are less than the limit value of 1.

Determination of the Sr/Ca ratio of tooth samples by photoactivation analysis in Southern Turkey

A nuclear analytical technique, namely instrumental photon activation analysis (IPAA), was used to determine Sr and Ca concentrations in human teeth. This work was conducted using the first accelerator facility, an off-shelf clinical linear accelerator (cLINAC), in Turkey. The tooth samples supplied by the Akdeniz University Faculty of Dentistry were analyzed for determination of the Sr/Ca element ratio. The results were obtained to demonstrate the impact of socioeconomic changes on dietary habits. A calibration material (CM; a mixture of calcium and strontium oxides) was required for quantification of the analytical results. The tooth samples, together with the CM, were exposed to 18 MeV end-point energy bremsstrahlung photons from the cLINAC. Thereafter, the γ-ray spectra of the samples and the CM were obtained using high resolution γ spectroscopy. Variations in the Sr/Ca ratio in the teeth of patients fed with beef and fizzy beverages were investigated in this study.

Attenuation properties of radiation shielding materials such as granite and marble against γ-ray energies between 80 and 1350 keV

In this study, the γ-ray energy-dependent mass and linear attenuation coefficients of various granite and Turkish marble species have been experimentally obtained. Radionuclides (133Ba, 137Cs, 60Co and 22Na) with point geometry were used as γ-ray sources. The absorption capacity of each sample at nine γ-ray energies was measured using a high resolution γ-ray spectrometer equipped with a high purity germanium (HPGe) detector. To obtain the precision of the results (1σ standard deviation of the single value), this procedure was repeated six times for each species of granite and marble, respectively. The energy-dependent mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), the half (HVL) and the tenth value layer (TVL) were calculated following that the MAC and LAC results were compared to the literature values.

Determination of self-attenuation correction factor for lichen samples by using gamma-ray spectrometry

In this study, we determine the self attenuation correction factor for lichen samples collected from Erzurum, a city located in the eastern region of Turkey by using gamma-ray spectrometry. The self attenuation correction factor is calculated for 17 lichen samples with densities ranging from 0.683 g/cm3 to 0.886 g/cm3. The transmission method has been used to obtain self-attenuation correction factors. Self attenuation correction factor versus energy fit curve is presented. It is observed that self attenuation correction factor changes with density. At lower energies the self-attenuation correction factor has higher values. At higher energies it has smaller values and tends to become stable.

Multielemental analysis of some soils in Karaman by PAA using a cLINAC

In this analytical work, some components (Sr, Ni, Mg, Fe, Zr, Cd, As, Ca, Br, Rb, Mn, I, Zn, Pb, Tl, U and Ba) of soil samples collected in different locations in the surroundings of Karaman, Turkey were determined by photon activation analysis (PAA). This method is based on photonuclear reactions. (γ,n), (γ,2n), (γ,γ') and (γ,p)-type reactions have been observed. The samples were irradiated with bremsstrahlung photons produced by a clinical electron linear accelerator (cLINAC) for up to about 85min. The PAA results were compared with those obtained by X-ray fluorescence (XRF).

Determination of activity concentration of natural and artificial radionuclides in sand samples from mediterranean coast of Antalya in Turkey

In this paper, we attempt to determine the activity concentration of natural and artificial radionuclides in 37 sand samples from the Mediterranean coast of Antalya in Turkey by using a high purity Germanium (HpGe) detector. 238U, 232Th, 40K and 137Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard index of sand samples are determined res-pectively. The average values are 13.43 ± 0.21 Bq/kg, 6.96 ± 0.06 Bq/kg and, 122.46 ± 18.58 Bq/kg, for 238U, 232Th and 40K respectively. Most of the activity concentration values are less than below minimum detection limit for 137Cs. The average values of the absorbed dose rate D (nGy/h), annual effective dose equivalent AEDE(μSv/y), radium equivalent activity Raeq (Bq/kg), external hazard index Hex and internal hazard index Hin are 15.52 nGy/h, 19.03 μSv/y, 32.81 Bq/kg, 0.09 and 0.12 respectively. It is observed that 238U, 232Th, 40K and 137Cs activity concentrations, absorbed dose rate, annual effective dose equivalent, radium equivalent activity are in the limit of the published values, external and internal hazard index values are less than unity.