Average Radioactivity Research Articles

Radiological characterisation of freshwater fish species from strategic locations in Bangladesh

A radiological assessment of inland freshwater fishes of wetland haor zones, near a uranium mine and Rooppur Nuclear Power Plant (RNPP) areas, was performed. Gamma spectrometric analysis showed the accumulation of 226Ra, 228Ra, and 40K in all studied fishes, with varying degree levels of concentrations. The average radioactivity levels of 226Ra, 228Ra and 40K in haor fish samples ranged from 2.76 ± 1.51 to 22.02 ± 3.81 Bq kg−1, 1.78 ± 0.69 to 21.53 ± 1.40 Bq kg−1 and 405.51 ± 22.04 to 749.80 ± 42.65 Bq kg−1, respectively. Conversely, the respective values for Bata fish samples of Rooppur Nuclear power plant sites varied from 2.66 ± 0.80 to 6.62 ± 0.81 Bq kg−1, 2.31 ± 0.62 to 5.18 ± 49.81 Bq kg−1 and 342.00 ± 4.98 to 461.45 ± 18.00 Bq kg−1, respectively. Activity levels of Taki fish (Channa punctatus) from haors zones were almost 3–4 times higher than the Meni fish (Nundus nundus) of the same locations and Bata fish (Labeo bata) of the RNPP site. The general public may attain doses of 244.54 µSv from the consumption of haor fish and 84.02 µSv from the fish of the RNPP sites yearly. The chance of an increase in cancer risk from intake of haor fish was higher than the ICRP values of 2.9 × 10−4. Univariate statistics showed that 226Ra and 228Ra radionuclides do not normally distribute, whereas 40K is normally distributed in the studied fish species. Multivariate statistical analysis demonstrated that the radioactivity and estimated radiological parameters are strongly positively correlated with 226Ra and 228Ra, and also positively correlated with 40K. Hence, it indicated that the contents in the freshwater fish species are usually controlled and influenced by similar geogenic sources and occur together. It is presumed that the radiological risk is mostly associated with and dominated by the uranium and thorium series and non-series 40K radionuclides in the freshwater fish species.

Assessment of natural radioactivity concentration in the soil samples from the Churchandpur and Ukhrul districts of Manipur, India.

The natural radioactivity concentration was studied for 40 soil samples of the Churchandpur and Ukhrul districts of Manipur, India, by using gamma-ray spectroscopy. The average radioactivity concentration of 226Ra, 232Th and 40K in Churchandpur was found as 39.9 (range: 30-56), 72.1 (range: 57-93) and 564.1 (range:360-867) Bqkg-1 respectively, whereas, in Ukhrul, average radioactivity for the same was found as 30.3 (range: 16-54), 54.2 (range:24-89) and 637.1(range:103-901) Bqkg-1, respectively. The calculated radioactivity parameters were compared with the world average values. The measured radium equivalent activity (Raeq), absorbed dose rate ($\dot{\mathrm D}$), annual effective outdoor dose(Ė) and the external hazard index (Hex) were observed as 165 (range: 63.7-234.8) Bqkg-1, 77.6 (36.9-108.0) nGyh-1, 0.11 (0.05-0.13) mSvy-1 and 0.5 (0.1-0.6), respectively. This study aims to provide baseline data for radionuclide present in the Churchandpur and Ukhrul districts of Manipur.

Radioactivity of Technosols on thermal power station ash disposal sites: Assessment of potential radiological human‐health risk

AbstractSoil radioactivity is a poorly recognized form of land degradation; however, there are regions all around the world where it can be dangerous to the environment and human health. The aim of the study was to analyze the radioactivity of Technosols developed on thermal power station (TPS) ash disposal sites. Total concentration of uranium (U), thorium (Th), and cesium (Cs), as well as the radioactivity of select radionuclides in Technosols were determined to recognize the level of radioactivity and to assess the potential radiological health risk. Total U, Th and Cs concentrations in Technosols were in ranges 1.5 to 11.3, 4 to 22.9, and 0.2 to 21.3 mg·kg−1, respectively. The radioisotope activities in Technosols (in Bq·kg−1) were in the 1.6–25.5 (137Cs); 29.2–1265 (40K); 26.2–99.9 (228Th); 27.9–100 (228Ra); 20.5–134. (226Ra); 32.8–177 (210Pb); 23.9–144 (238U); 1.2–7.0 (235U) ranges. The activity concentrations were slightly higher than the activities of non‐contaminated soils. Technosols developed from bituminous coal ash had higher 40K, 228Th, and 228Ra activity concentrations than soils developed from lignite ash. Artificial 137Cs occurred in surface horizons of Technosols due to fall of atmospheric dust enriched in 137Cs. Annual effective dose (AED) in Technosols amounted 0.07–0.16 mSv·a−1 and was somewhat higher than the global and Polish average (0.06 and 0.07 mSv·a−1, respectively) for outdoor external terrestrial radiation. The radioactivity of the investigated Technosols is slightly above the average radioactivity of native soils. The radiological human‐health risk related to the analyzed soils is low.

Assessment of natural radioactivity in the RCC building materials used in the valley region of Manipur, India.

An assessment of radioactivity concentration of reinforced cement concrete types of house was conducted in the valley region of Manipur, India. The average radioactivity concentration of 226Ra, 232Th, and 40K of portland cements are 39 (range: 32-52) Bqkg-1, 36 (range: 22-62) Bqkg-1, and 1812 (1254-2424) Bqkg-1; for concrete are 36 (range: 26-45) Bqkg-1, 65 (range: 45-86) Bqkg-1, and 660 (639-681) Bqkg-1; for sand are 45 (30-61) Bqkg-1, 114 (range: 55-212) Bqkg-1, and 1859 (range: 1413-2232) Bqkg-1; and for bricks are 30 (range: 24-37) Bqkg-1, 148 (range:79-184) Bqkg-1, and 1444 (range: 1093-2103) Bqkg-1, respectively. The annual effective dose was observed with an average value of 1.9 (range: 0.9-3.3) mSvy-1. However, gamma index was observed with an average value of 1.1 (range: 0.5-2.0).

Determination of natural and artificial radioactivity levels and radiation hazard indices for soil samples in Kırşehir

Abstract The aim of this study is to create a radiological map of Kırşehir province in Turkey by analyzing the radioactivity levels of soil samples and environmental radiation measurements. 226Ra, 232Th, 40K and 137Cs radionuclides were analysed in soil samples collected from 47 locations using gamma spectrometry with an HPGe detector. According to the results obtained, gamma radioactivity concentration ranges and mean values for 226Ra, 232Th, 40K and 137Cs were determined as 133 ± 15–1515 ± 128 Bq/kg (599.40 Bq/kg), 0.3 ± 0.09–21.1 ± 1.7 Bq/kg (4.61 Bq/kg), 8.7 ± 0.9–128.5 ± 8.5 Bq/kg (29.66 Bq/kg) and 11.6 ± 8.6–273.8 ± 19.9 Bq/kg (48.80 Bq/kg) respectively. Average radioactivity levels for 40K and 232Th are above the world average. The mean radium equivalent activity (Raeq), gamma dose rate (D), annual effective dose equivalent (AEDE), external hazard index (H ex ), and the excess lifetime cancer risk (ELCR) were calculated as 145.45 Bq/kg, 122.13 nGy/h, 0.15 mSv/h, 0.39 and 0.29 × 10−3 respectively.

Effects of Natural Radioactivity of Some Chemical and Organic Fertilizers on Gonads in Iraqi Kufa Markets

This study assessed the hazard indicators of common chemical and organic fertilizers widely available in the markets of Najaf Governorate, Iraq. The concentrations of natural radionuclides were measured in thirteen types of fertilizers by Gamma spectrum using NaI(Tl) (3*3) detector. The average radioactivity of the nuclides 226Ra, 232Th, and 40K was (48.91, 37.04, and 702.4675) Bq.kg-1, respectively, for (Di-Aluminum Phosphate) the chemical fertilizers of the type (DAP) and the (nitrogen, phosphorus, and potassium) chemical fertilizers of the type (NPK) the average radioactivity of the nuclides 226Ra, 232Th, and 40K were (35.78, 42.356 and 1519.653) Bq.kg-1, respectively, while the average radioactivity of the organic fertilizers (Orga.) were 55.153, 23.148 and 1451.258 for the three studied nuclei. As for the average values for radium equivalent were 155.967, 213.363, and 200.0023 (Bq.kg-1) for (DAP), (NPK) and organic fertilizers, respectively. The values of the external severity index (Hex), gamma radiation hazard index (Iγ), and representative alpha index (Iα) were within the permissible limits determined by the UNCEAR 2000. The highest value of total annual effective dose equivalent(TAED) was 1.468 mSv.y-1, the lowest value was 0.302 mSv.y-1, and the mean values were 0.722 mSv.y-1. In contrast, the highest value for annual gonadal dose equivalent(AGED) was 1392.527 μSv.y-1, the lowest value was 275.361 μSv.y-1, and the average values for all models were 672.135 μSv.y-1. The Excess Lifetime Cancer Risk (ELCR), the highest value was 4.039 × 10-3, the lowest value was 0.833× 10-3, and the average value was 1.988× 10-3 for all fertilizers. The Pearson correlation between radioactive variables and cluster analysis was recognized for the three types of fertilizer samples despite it not being widely accepted. The study can be considered preliminary data for subsequent studies.

Radiosynthesis and Analysis of (S)-4-(3-[18F]Fluoropropyl)-L-Glutamic Acid

Purpose(S)-4-(3-[18F]Fluoropropyl)-L-glutamic acid ([18F]FSPG) is an L-glutamate derivative used as a PET biomarker to assess intracellular redox status in vivo through targeting of the cystine/glutamate antiporter protein, xc− transporter. In this report, we describe a radiosynthesis of [18F]FSPG for use in PET studies that address specific challenges in relation to the radiotracer purity, molar activity, and quality control testing methods.ProceduresThe radiosynthesis of [18F]FSPG was performed using a customised RNPlus Research automated radiosynthesis system (Synthra GmbH, Hamburg, Germany). [18F]FSPG was labelled in the 3-fluoropropylmoiety at the 4-position of the glutamic acid backbone with fluorine-18 via substitution of nucleophilic [18F]fluoride with a protected naphthylsulfonyloxy-propyl-L-glutamate derivative. Radiochemical purity of the final product was determined by radio HPLC using a new method of direct analysis using a Hypercarb C18 column.ResultsThe average radioactivity yield of [18F]FSPG was 4.2 GBq (range, 3.4–4.8 GBq) at the end of synthesis, starting from 16 GBq of [18F]fluoride at the end of bombardment (n = 10) in a synthesis time of 50 min. The average molar activity and radioactivity volumetric concentration at the end of synthesis were 66 GBq µmol−1 (range, 48–73 GBq µmol−1) and 343–400 MBq mL−1, respectively.ConclusionStability tests using a 4.6 GBq dose with a radioactivity volumetric concentration of 369 MBq mL−1 at the end of synthesis showed no observable radiolysis 3 h after production. The formulated product is of high radiochemical purity (> 95%) and higher molar activity compared to previous methods and is safe to inject into mice up to 3 h after production.

Natural radioactivity and its radiological implications from soils and rocks in Jaintiapur area, North-east Bangladesh.

Natural radioactivity concentrations in recent alluvial soils from swampy areas and Tertiary rocks from Jaintiapur were measured using gamma-ray spectrometer equipped with HPGe detector. The average radioactivity concentration of 226Ra, 232Th and 40K were 47 ± 6, 64 ± 5 and 762 ± 40 Bqkg−1 in soils, whereas, 25 ± 2, 37 ± 4 and 884 ± 41 Bqkg−1 in rock samples, respectively. Average radioactivity concentrations of studied soil and rock samples exceeded the world average except 226Ra for rocks. Radio-elemental ratios suggest that an oxic depositional environment with low uranium and high thorium content. Regarding radiological hazard indices, radium equivalent activities (Raeq), external hazard index (Hex) and internal hazard index (Hin) was found to be below the world permissible limits. Whereas, absorbed dose rate (D), and annual effective dose equivalent (AEDE) averages exceeded the world admissible values. Statistical studies show that radioactivity for 226Ra and 232Th linked to a source enriched in radioactive minerals and 40K related to a different sources high in K enriched minerals.

Experimental Study on the Localization and Estimation of Radioactivity in Concrete Rubble Using Image Reconstruction Algorithms

To reduce a large amount of contaminated concrete rubble stored in the Fukushima Daiichi Nuclear Power Station site, recycling low-radioactivity rubble within the site is a possible remedy. To promote recycling while ensuring safety, not only the average radioactivity but also the radioactivity distribution of concrete rubble should be efficiently evaluated because the details of rubble contamination caused by the accident remain unclear and likely include hotspots. However, evaluating inhomogeneous contamination of thick and/or dense materials is difficult using previous measurement systems, such as clearance monitors. This study experimentally confirmed the potential applicability of image reconstruction algorithms for radioactivity distribution evaluation in concrete rubble filled in a chamber. Radiation was measured using plastic scintillation fiber (PSF) around the chamber ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$50\times 50\times40$ </tex-math></inline-formula> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ). Localized hotspots were simulated using standard sources of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">137</sup> Cs, which is one of the main nuclides of contaminated rubble. The radioactivity distribution was calculated for 100 or 50 voxels (voxel size: (10 cm) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> or 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times 10\times20$ </tex-math></inline-formula> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) constituting the chamber. For 100 voxels, inner hotspots were undetected, whereas for 50 voxels, both inner and surface hotspots were reconstructible. The distribution evaluated using the maximum likelihood expectation–maximization (ML-EM) algorithm was the most accurate; the average radioactivity was estimated within 70% accuracy in all seven cases.

Measurement and Analysis of the Distribution of Pb-214 Lead Isotope in Baghdad Soil using Remote Sensing Techniques

The present research aims to measure concentration of lead Pb214 in soil using remote sensing and GIS, associated radiological hazards in Baghdad, Iraq. Concentration of specific radioactivity of radioactive elements was measured and analyzed naturally and artificially in 48 soil samples for separate sites from Baghdad, Iraq using crystalline spectroscopy to detect germanium. The average radioactivity concentrations of lead were found, as it was found to have varying values ​​from one site to another, as most of them exceeded the international permissible limit, as the highest concentration was recorded at 180 Bq in the sample H28 in Waziriyah district. Battery Lab (1), and the lowest concentration value is 40Bq in (H4, H15, H45) which represents (Dora Expressway, Mansour Street, Fuel Express, and Mahmoudiya Road 2).&#x0D; Remote sensing data techniques, and Global Positioning System (GPS) have been used to analyze the effect of the isotopic distribution of heavy bullets for the city of Baghdad. Using Geographic Information Systems (GIS), concentrations were measured and observed. Results of interpolation maps showed isotope of lead is concentrated in the center and west of Baghdad, and then graded with fewer values in other sites.

Determining the minimal ultra-low dose CT for reliable attenuation correction of 18F-FDG PET-CT: a phantom study.

To investigate minimal required sub milli-Sievert (mSv) ultra-low dose CT and corresponding tube current and voltage for reliable attenuation correction and semi- quantitation in 18F-FDG PET-CT in an effort for radiation dose reduction. Methods: We performed a PET-CT investigational study using a NEMA torso phantom containing six spheres (diameter: 10, 13, 17, 22, 28, 37 mm) filled with a fixed concentration of 60 kBq/ml and a background of 15 kBq/ml of 18F-FDG. Two sets of PET images, separated by 2 hours, were acquired for 3 minutes in a single bed position using 3-D mode with and without time-of-flight in a GE D-690 scanner. Several sets of CT images were acquired for attenuation correction with different combinations of tube voltage (80, 100, 120 kVp) and effective mAs (tube current-time product divided by pitch), using the maximum beam collimation (64 x 0.625 mm). The lowest CT acquisition technique available on this scanner is 10 mA, 0.4 s and 1.375 for the tube current, tube rotation time and pitch, respectively. The CT radiation dose was estimated based on the computed tomography dose index volume (CTDIvol) measurements performed following the standard methodology and the Imaging Performance Assessment of CT Scanners (ImPACT) calculator. Each of the CT techniques was used for attenuation correction to the same PET acquisition, using ordered-subset expectation maximum (OSEM) algorithm with 24 subsets and 2 iterations. The maximal and average radioactivity (kBq/ml) and standardized uptake values (SUV) of the spheres were measured. The minimal ultra-low dose CT for attenuation correction was determined by reproducible SUV measurements (±10%) compared to our reference CT protocol of 100 kVp and 80 mA for 0.5 s rotation. Results: The minimal ultra-low dose of CT for reproducible quantification in all spheres (<10% relative difference) was determined to be 0.3 mSv for a combination of 100 kVp and 10 mA at 0.5 s rotation, 0.984 helical pitch (0.26 mGy measured CTDIvol) . Based on these results we could confidently determine the CT parameters for reliable attenuation correction of PET images while significantly reducing the associated radiation dose. Conclusion: Our phantom study provided guidance in using ultra-low dose CT for precise attenuation correction and semi-quantification of 18F-FDG PET imaging, which can further reduce CT dose and radiation exposure to patients in clinical PET-CT studies. Clinical application: Based on the data, we can further reduce the radiation dose to sub-mSv using an ultra-low dose CT protocol for reliable attenuation correction in clinical 18F-FDG PET-CT studies.

Radiological Risk to Human and Non-Human Biota Due to Radioactivity in Coastal Sand and Marine Sediments, Gulf of Oman.

Natural and 137Cs radioactivity in coastal marine sediment samples was measured using gamma spectrometry. Samples were collected at 16 locations from four beaches along the coastal area of Muscat City, Gulf of Oman. Radioactivity in beach sand was used to estimate the radiological risk parameters to humans, whereas the radioactivity in marine sediments was used to assess the radiological risk parameters to non-human biota, using the ERICA Tool. The average radioactivity concentrations (Bqkg−1) of 226Ra, 232Th, 40K, 210Pb and 137Cs in sediments (sand) were as follows: 16.2 (16.3), 34.5(27.8), 54.7 (45.6), 46.8 (44.9) and 0.08 (0.10), respectively. In sand samples, the estimated average indoor () and outdoor () air absorbed dose rates due to natural radioactivity were 49.26 and 27.4 and the total effective dose (; µSvy−1) ranged from 150.2 to 498.9 (average: 275.2). The measured radioactivity resulted in an excess lifetime cancer risk (ELCR) in the range of 58–203 (average: 111) in and an average gonadal dose (AGD; µGy.y−1) ranged from 97.3 to 329.5 (average: 181.1). Total dose rate per marine organism ranged from 0.035 µGy h−1 (in zooplankton) to 0.564 µGy h−1 (in phytoplankton). The results showed marine sediments as an important source of radiation exposure to biota in the aquatic environment. Regular monitoring of radioactivity levels is vital for radiation risk confinement. The results provide an important radiological risk profile parameter to which future radioactivity levels in marine environments can be compared.

Biological role of postoperative low level laser therapy in preventing hydroxyapatite orbital implantation exposure: A case report.

Conjunctival sac stenosis is the contraction of the conjunctival sac as a result of trauma or disease. The aim of the present study was to observe the clinical effects of low-level laser therapy (LLLT) combined with hydroxyapatite (HA) orbital implantation as a treatment strategy for conjunctival sac stenosis. A total of 10 patients with conjunctival sac stenosis were treated with scleral graft transplantation in conjunction with HA implantation and postoperative LLLT. In addition, a rabbit model was used to investigate the biological mechanism underlying the effects of LLLT with the aim of preventing and treating orbital implantation exposure. The right eyeball was removed, orbital implantation performed and LLLT applied to experimental groups. 99mTc-Methyl diphosphonate scanning methods were performed at different timepoints to compare the average radioactivity count of the region of interest between surgical (right) and control (left) eyes (R/L). Histopathological examination was performed 8 weeks post-surgery, followed by analysis of fiber vascularization. Following LLLT, moderate conjunctival wounds were completely healed within 2 weeks and severe stenosis wounds healed within 3 weeks. Following prosthesis implantation in the rabbit model, a significantly elevated R/L ratio was observed after 4 weeks, whereas no significant difference was observed compared with the control group at 6 and 8 weeks postoperatively. Histopathological examination revealed that all implants were fibrotic. Overall, the present study demonstrated that LLLT promoted the survival of conjunctival grafts, stimulated conjunctival incision healing and promoted early vascularization of HA implants. Clinical trial registration no: ChiCTR-DDT-12002660 (www.chictr.org/cn/).

Isolation, characterization and source analysis of radiocaesium micro-particles in soil sample collected from vicinity of Fukushima Dai-ichi nuclear power plant

Radioactive caesium was released during the accident of Fukushima Dai-ichi nuclear power plant (FDNPP) into the surrounding environment. In the current work, radiocaesium micro-particles (CsMPs) and radiocaesium-rich soil particles were selectively separated from soil particles as well as from each other using autoradiography-based procedure. The applied separation scheme is based on water dilution followed by drying of the soil sample prior to imaging plate autoradiography. The SEM/EDS investigation of the individual CsMPs showed that these particles have a silicate glass structure and vary in shape with a diameter less than 10 μm. For the first time, a two-stage formation mechanism was suggested for a CsMP based on shape and structure heterogeneity of its two parts. Perfect spherical core might be formed in the first stage with a remarkable lower content of Al, and relatively higher concentrations of Si and K than an outer angulated structure, which might be attached to the core sphere during a late stage.The radiocaesium-rich soil particles have bigger size than CsMPs and have a plate-like structure with cleavages inside the grains, which suggest that these particles might be a weathered biotite. The average radioactivity ratio of 134Cs/137Cs (dated March 11, 2011) in the investigated particles was found to be 1.05 ± 0.01, which confirmed that the radiocaesium in CsMPs and in the contaminated soil particles has the same source of origin, which could be unite 3 of FDNPP.

Estimation of Natural Radionuclides’ Concentration of the Plutonic Rocks in the Sakarya Zone, Turkey Using Multivariate Statistical Methods

The study aimed to determine the natural radioactivity levels of 226Ra, 232Th, and 40K by the Gamma-Ray spectrometry method, and radiological hazard parameters of the plutonic rocks in the Western and Central Sakarya Zone and to analyze the data using multivariate statistical methods. The average radiological values of samples were determined as 40K (1295.3 Bq kg−1) &gt; 232Th (132.1 Bq kg−1) &gt; 226Ra (119.7 Bq kg−1). According to the skewness values of the distributions of the examined radionuclides, 226Ra (2.1) and 232Th (0.7) seemed to be positively right-skewed while 40K (−0.2) had a negatively right-skewed histogram. On the other hand, the following kurtosis values were calculated for the distributions: 226Ra (5.8 &gt; 3), 232Th (−0.7), and 40K (−0.8). Kolmogorov–Smirnov and Shapiro–Wilk tests were applied to the data to test their normality. Therefore, Spearman’s correlation coefficient method was performed. The radionuclides of 226Ra and 232Th were found to have a positive correlation with radiological hazard parameters of the samples. 2 (two)-related factors identified, and the cumulative value was calculated to be 98.7% on the basis of the Scree Plot. According to the hierarchical cluster analysis, the samples that are grouped with those from Camlik region are prominent. The average radioactivity values of Camlik, Sogukpinar, Karacabey, and Sogut (except for 232Th) regions were detected to be higher than the world averages while the value of 40K was also found to be higher than the average values of various countries in the world.

Determination of radioactivities in gamma vulcanized natural rubber latex (GVNRL) for the assessment of radiological safety

Due to great potentials of utilizing products made from gamma vulcanized natural rubber latex (GVNRL) in applications that require less use or less release of hazardous chemicals during rubber vulcanization, the radiological health risks in rubber producers/users caused by radioactivities from natural radioisotopes containing in GVNRL must be thoroughly determined and evaluated. As a result, this work determined the activity concentrations of 226Ra, 232Th, and 40K in GVNRL samples that were pre-vulcanized with 12-kGy and 24-kGy gamma irradiation using gamma spectroscopy. The results showed that the average radioactivity concentrations (± standard deviation) of 226Ra, 232Th, and 40K in 12-kGy (24-kGy) GVNRL were 30.8±1.5 (31.2±2.7) Bq kg-1, 89.1±0.6 (89.7±0.4) Bq kg-1, and 95.4±1.6 (93.2±2.2) Bq kg-1, respectively. These results implied that GVNRL vulcanized with 12-kGy and 24-kGy gamma irradiation had statistically similar radioactivity concentrations and higher gamma doses did not result in increasing radioactivies. Furthermore, when compared these results with the values from nonvulcanized natural rubber latex (NRL), of which the activity concentrations of 226Ra, 232Th, and 40K were 29.9±1.2 Bq kg-1, 95.2±1.1 Bq kg-1, and 96.2±1.0 Bq kg-1, respectively, it could be concluded that the use of gamma irradiation for rubber vulcanization did not statistically increase or change activity concentrations of the mentioned radioisotopes, thus, it is radiologically safe for related personnel to work or use GVNRL products.

Evaluation and assessment of 7 years of radioactivity monitoring data for Th232, Ra226, K40 on surface soil and the impact of the construction of mass rapid transit stations around pasar jumat nuclear area

Evaluation and assessment of 232Th, 226Ra, and 40K as natural radioactivity in surface soil in Pasar Jumat Nuclear Facility (PJNA) are important and are a routine activity to monitor the impact of human activities on changes in the level of natural radioactivity in soils. The monitoring data over 7 years period (2012 – 2018) was evaluated to show the time trends, the ratio concentration, and correlation between the outside of PJNA of natural radioactivity level on surface soils. The average radioactivity trend over 7 years monitoring of 232Th, 226Ra, and 40K concentration have varied data. While the mean ratio of 40K/232Th is range from 0.732 to 2.178. The average level of radioactivity concentration at surface soil during the pre-construction, construction, and operation of the MRT project for 232Th, 226Ra, and 40K are 23.34, 21.64, 21.56 bq/kg, then 19.30, 16.73, 18.93 bq/kg, and 27.47, 26.05, 22.26 bq/kg, respectively. The evaluation result state during the MRT project that only the concentration of 232Th on before construction period has a significantly different the mean. There was no influence of MRT construction on surface soil concentration.

Radioactive cesium concentrations in coastal suspended matter after the Fukushima nuclear accident

Radioactive cesium concentrations in the suspended matter of the coastal waters around the Fukushima Daiichi Nuclear Power Plant (FDNPP) were investigated between January 2014 and August 2015. The concentrations of radioactive cesium in the suspended matter were two orders higher in magnitude than those determined in the sediment. In addition, we discovered highly radioactive Cs particles in the suspended matter using autoradiography. The geometrical average radioactivity of particles was estimated to be 0.6 Bq at maximum and 0.2 Bq on average. The contribution ratio of highly radioactive Cs particles to each sample ranged from 13 to 54%, and was 36% on average. A major part of the radioactive Cs concentration in the suspended matter around the FDNPP was strongly influenced by the highly radioactive particles. The subsequent resuspension of highly radioactive Cs particles has been suggested as a possible reason for the delay in radioactive Cs depuration from benthic biota.

The determination of concentrations of radioisotopes in some granite samples in Turkey and their radiation hazards

ABSTRACTThe primordial radionuclides activity concentrations (226Ra, 40K and 232Th) are measured in some granite samples in this study. The collected granite materials are analyzed with NaI(Tl) gamma-ray spectrometry. The specific activity of 226Ra, 232Th and 40K values are in range 2.60 ± 0.10 to 178.9 ± 0.6 Bq kg−1, 1.46 ± 0.10 to 162.50 ± 0.75 Bq kg−1 and 19.8 ± 0.3 to 579.7 ± 2.8 Bq kg−1 respectively. The radium’s equivalent activity, annual effective dose, absorbed dose rate, hazard index, radioactivity level index, activity utilization’s index and exposure rate are calculated for determination of radiological risk. The concentration of 226Ra (in the 71.4% of samples), 232Th (in the 71.4% of samples) and 40K (in the 14.3% of samples) in the granite samples are higher than average radioactivity concentrations of this radio-isotopes defined by ICRP (35.0, 30.0 and 400.0 Bq kg−1, respectively).

210Po Radioactivity in Tobacco and Smoke Inhalation Effective Dose Estimation

In this study, 210 Po radioactivity in tobacco and effective dose estimation from smoke inhalation were investigated. 14 most frequently used cigarette brands in Turkey were used for this purpose. 210 Po average radioactivity in tobacco was found to be 25.4 ± 2.0 Bq/kg. 210 Po mean annual effective dose was found to be 181.8 µSv/y.