Activity Concentrations Of Radionuclides Research Articles

Natural and Artificial Radioactivity Concentrations and Health Risks due to Radionuclides in the Soil of Nevşehir (Cappadocia)

Natural and artificial radionuclides in the surface soil samples collected from the Nevşehir (Cappadocia) region were analyzed using gamma spectrometry employing an HPGe detector. Activity concentrations of 226Ra, 232Th, and 40K range from 58.31 to 77.40 Bq kg−1, 60.56 to 90.97 Bq kg-1, and 796.42 to 1142.8 Bq kg-1, respectively. The values indicate that the activity concentrations of the natural radionuclides in the soil samples were higher than the world average. Since Turkey is a country greatly affected by the Chernobyl accident, 137Cs activity concentration was measured to determine whether its effect continues. The activity concentration of 137Cs ranges from Minimum Detectable Activity (MDA) to 6.88 Bq kg−1. In addition, the radium equivalent activity, the absorbed dose rate, the annual effective dose equivalent, and the excess lifetime cancer risk parameters were calculated to determine the radiological effect of natural and artificial radionuclides on the population in the study area. All values except the radium equivalent activity were found to be above the world average.

Natural Radionuclide Concentration in Kaolin Deposits and Dose Assessment Within Delta State, Nigeria

The assessment of natural radionuclide concentration in kaolin deposits and dose rate within Delta state, Nigeria has been carried out. Four kaolin mining sites within four Local Government Areas in the state were studied. Background Ionizing Radiation levels of each of the mining site was measured using a Gamma Scout handheld radiation meter and a GPS meter used to obtain the actual positions where the BIR levels were taken around each kaolin site. A total of twenty-five (25) samples were collected for Gamma spectrometry analysis at National Institute of Radiation Protection and Research, University of Ibadan. The mean BIR exposure rates for Ukwuani, Aniocha South, Ughelli North and Ughelli South LGAs were 0.01mRh -1 , 0.013mRh -1 , 0.013mRh -1 and 0.014mRh -1 respectively and were within the world’s recommended permissible limit of 0.013mRh -1 given by UNSCEAR. The mean activity concentrations of 238 U, 232 Th and 40 K in kaolin samples were estimated to be 137.028 ± 7.194, 13.532 ± 1.568 and 6.724 ± 0.396 Bqkg -1 respectively for Ukwuani; 425.494 ± 22.16, 18.63 ± 2.17 and 11.955 ± 0.71 Bqkg -1 respectively for Ughelli South; 596 ± 30.772, 18.728 ± 2.124 and 8.912 ± 0.526 Bqkg -1 respectively for Ughelli North and finally, 120.026 ± 6.235, 10.533 ± 1.182 and 15.024 ± 0.879 Bqkg -1 respectively for Aniocha South. These results compare quite well with the world’s average value of activity concentrations for natural radionuclides reported by UNSCEAR, except for 40 K which is higher than the world’s average at Ughelli North and South. The values of all the radiological hazard parameters for all the mining sites are less than the recommended limits. The calculated Excess Lifetime Cancer Risk also reveal that the values are all within the recommended limits, therefore, the risk of cancer inducement due to radiation exposure is within the acceptable limits for all the mining sites.

Natural radionuclides behaviour in drinking groundwaters from Castilla y León (Spain); radiological implications

Since the coming into force of the European Council Directive 51/2013 EURATOM and its transposition into the Spanish legislation, the presence of radioactive substances in drinking waters must be kept under surveillance to ensure that the health protection requirements are met. Driven by this regulatory framework, in an attempt to know the starting point from which to design surveillance plans, the groundwaters intended for human consumption of Castilla y León (Spain) have been radiologically characterised by using both low-level γ-ray and α-particle spectrometry to determine the activity concentration of the natural radionuclides needed to account for the indicative dose estimation. This extensive research has comprised the radiological characterisation of more than 400 drinking water samples from one of the European Union's largest regions. Furthermore, the gross α and gross β activities have been analysed. Results showed a high geographical variability that can be related to the hydrogeological formations where the groundwaters come from. The uranium isotopes, 234U and 238U, are the main radionuclides present in the analysed drinking waters reaching values up to 2000 mBq/L, in the southwestern and western of Castilla y León, where U-rich minerals are part of the host rock. High 210Pb and 226,228Ra occurrences are found in the low permeability igneous and metasedimentary hydrogeological formations of Salamanca province. From a public health protection point of view, 4.4% of the total drinking water samples from intakes exceeded the Indicative Dose parametric value of 0.1 mSv, which is a not negligible number of samples, being very likely related to granitic and metamorphosed host rock under specific local conditions. This fact highlights the need for research and consideration of special surveillance of the groundwaters from these areas.

Redistribution of radionuclides in wall material and its effects on the room dose rate

Here we investigate the annual effective dose rate obtained from gamma radiation emitted from radionuclides in construction materials in a model room with fixed dimensions. The dose rate is calculated on the whole room area at half the room height. We focus our analyses on a comparison of the annual effective dose rate between the room centre and the room average at half the room height and provide wall-wise quadratic index equations for both. We find that the annual effective dose rate based on the room average is larger than for the room centre due to increased annual effective dose rates for positions in the room closer to the walls. Furthermore, we evaluate the annual effective dose rate under a non-equal distribution of radionuclides in the three wall types (floor and ceiling, long walls, short walls). When considering the room average of the annual effective dose rate, our analysis indicates that it appears advantageous to use construction materials with a higher radionuclide activity concentration for floor and ceiling and the material with a lower radionuclide content for long and short walls, if there is a choice in the construction process.

Occupational radiological risk assessment and quantification of natural radionuclides present in Pakistani coal

ABSTRACT In this study, 47 coal samples from 16 selected coal mines from four provinces of Pakistan (Punjab, Sindh, Balochistan, and Khyber Pakhtunkhwa) were collected and analysed using a HPGe-based gamma spectrometry system. The objective of the study was to assess the occupational radiological risk from coal reserves in Pakistan. The 226Ra concentration values were found to be higher in coal samples collected from two locations in Meting-Jhumpir Coal Fields and one location of Chakwal Coal Field as compared to the recommended value by UNSCEAR (2000). The 232Th concentration values were found to be higher in coal samples collected from two locations in Padhrar Coal Field, one location in Dandot Coal Field and one location in Cherat Coal Field as compared to the recommended value by UNSCEAR (2000). The 40K values in all the analysed samples were found to be well below the recommended value by UNSCEAR (2000). From the radiological parameters, the values of the representative gamma index, which corresponds to an annual effective dose, were found to be higher than 1 Bq-kg−1 among the samples collected from Meting-Jhumpir coal fields, Chakwal coal field, Padhrar coal fields, Dandot coal fields, Hangu coal field, and Cherat coal fields. Excess lifetime cancer risk was estimated to be in the range of 0.07 × 10−3 − 0.34 × 10−3 with an average value of 0.18 × 10−3. The annual effective dose was estimated in the range of 0.01–0.07 µSv- y−1, which is below than the value established by the IAEA as the safe limit for the public in a planned exposure situation (1 mSv-y−1). It can be concluded that for some of the coal fields, the radionuclide concentration values and some of the radiological parameter values were found to be higher than the recommended values. Site-specific studies using direct radiation and radon measurement instruments are proposed for these coal fields to further investigate the radiological situation and its implications on workers and the public’s health. Furthermore, we have used a theoretical approach to estimate the occupational health hazard based on the activity concentration of radionuclides in the coal samples, which needs to be validated with the direct-dose measurement techniques.

Determination of Transfer Factor for Some Crops in Selected Cultivated Soils, Khidir City, Iraq

The current study dealt with the activity concentrations of some radionuclides in several common plants and corresponding soils in Khidir City, Iraq. The radioactivity measurements are carried out for 226Ra, 232Th, and 40K in some consumable crops and their soils using gamma spectrometry with an HP germanium detector. The sampling process included 8 crops, averaging 7 samples for each plant and surrounding soils equally. The studied crops consisting of okra, onions, cucumber, tomatoes, eggplant, sweet potato, zucchini, and organic pepper showed obvious variability as follows: the activity levels of 226Ra varied from 0.16±0.1 Bq/kg (in eggplant) to 3.984±0.19 Bq/kg (in tomato), with an average of 1.57±0.14 Bq/kg. 232Th were found to be within the range of (0.023±0.01 - 2.93±0.19 Bq/kg) (in onions – in cucumber), and an average value of 0.80±0.12 Bq/kg. For 40K ranged between 87.801±2.24 Bq/kg (in cucumber) and 409.45±2.94 Bq/kg (in tomato), with an average of (273.53±2.43 Bq/kg). On the other hand, the radionuclides activity concentrations in the corresponding soils ranged between 4.644±0.24 Bq/kg, with an average of 16.124±0.50 Bq/kg for 226Ra, and from 1.315±0.11 Bq/kg to 22.783±0.61 Bq/kg, with a mean value of 8.32±0.32 Bq/kg for 232Th, and from 284.482±2.48 Bq/kg to 451.468±3.93 Bq/kg, with a mean value of 406.53±2.77 for 40K. The concentrations of 226Ra and 232Th in the plants and soil samples were lower than the permissible values reported by UNSCEAR. In contrast, the activity level of 40K exceeded the allowed level suggested by UNSCEAR. Moreover, the obtained data were statistically analyzed and discussed in detail. Furthermore, the soil-to-plant transfer factors were calculated for the crops under study. TF of 226Ra was found to be within the range of (0.056-0.143), with an average of 0.095, for 232Th ranged between 0.056 and 0.192, with an average of 0.101, while for 40K, it is found to be varied from 0.933 to 0.216, with an average of 0.669. transfer factors of all crops were lower than the unity value conducted by IAEA.

Dolphin-shaped island: Exploring the natural resources and radiological hazards of Wadi El Gemal Island

The objective of this study is to assess the natural resources and radiological risks of Wadi El Gemal Island by examining its topography, mineralogy, geochemistry, and radioactive distributions. This island, which is situated at the outlet of Wadi El Gemal in Egypt's southeastern Desert, has a unique shape resembling a dolphin based on Landsat imagery. It's a part of the Wadi El Gemal-Hamata Protectorate and is notable for its diverse environmental, geological, economic, and archeological features, including recent reefs, sandy deposits, Quaternary carbonate sediments, and mangroves. The main natural resources on the island are fauna, mangrove forests, and flora. Samples collected from the island were analyzed using a NaI detector to measure the concentrations of radionuclides such as 238U, 232Th, 226Ra, and 40K, which were found to be within acceptable levels according to UNSCAR guidelines. The radionuclide 238U, 232Th, 226Ra, and 40K activity concentrations of the collected samples were 32.55 ± 9, 12.63 ± 4, 12.49 ± 4, and 325 ± 34 Bq/kg, respectively. Regarding radiological hazard indices, the values of absorbed gamma dose rate (36.06 ± 5.42 nGy/h), radium equivalent activity (73.88 ± 14.4 Bq/kg), annual effective dose indoor (0.18 ± 0.03 mSv/y) and outdoor (0.04 ± 0.01 mSv/y), internal (0.29 ± 0.05) and external (0.2 ± 0.03) indices, and excess lifetime cancer index (0.15 ± 0.05 × 10−3).This is suggest that there is no significant risk associated with these sediments.

Evaluation of radiological hazards in lower zab river sediments

In this study, the activity concentrations of natural and artificial radionuclides in 18 sediment samples were investigated from Iraq’s Upper and Lower Dukan Dam using the high-purity germanium (HPGe) detector as a gamma-ray spectrometry technique. The results revealed that the values of the activity concentration of 226Ra, 232Th, 40K, and 137Cs sediment ranged from (2.85–24.60 Bq kg−1), (1.27–7.56 Bq kg−1), (42.14–346.60 Bq kg−1), and (0.14–3.62 Bq kg−1), respectively. The radiological risk parameters such as radium equivalent activity, absorbed dose rate, annual effective dose equivalent, and external hazard index were determined and found to be 30.98 Bq kg−1, 14.97 nGy h−1, 29.62 nGy h−1, 0.019 mSv y−1, 0.153 mSv y−1, 0.08, and 0.11, respectively. The observed mean values were comparable to internationally recommended values. The field dose rates were measured using the RIIDEye Handheld Radiation Isotope Identifier, and the range was 23.5 nsv h−1–80.6 nsv h−1. The data obtained in this study can be used as a baseline for future investigations of radioactivity background in the investigated area.

Dating of groundwater using uranium isotopes disequilibrium in Siwa Oasis, Western Desert, Egypt

Data on the recent migratory history of radionuclides as well as geochemical circumstances can be obtained from the disequilibrium of the uranium series, which is often brought on by groundwater flow and host rock. Groundwater from the Siwa Oasis is a vital source of water for many uses, and it is distributed widely throughout the Western Desert. Groundwater in Siwa Oasis was dated using measurements of uranium in the water. In water samples that exhibited disequilibrium behavior, the activity concentrations of radionuclides from the 238U, 235U and 232Th series were measured. Therefore we conclude that the measured waters are rich in the 234U and 230Th. The secular equilibrium between 234U and 230Th indicates that colloidal transport could be the mechanism for the mobility of 230Th in groundwater. Higher 230Th levels in the samples show that the aquifer is deep and may have a large amount of thorium-bearing minerals. The lake and groundwater estimated ages showed that the time of uranium migration happened between 60 and 130 ka ago. This aquifer is rich in mineral deposits, as evidenced by the extraordinarily high content of radionuclides. The 230Th/232Th activity ratio of the samples, indicating pure carbonate minerals, ranged from 12.58 to 20.86.

Transfer of 137Cs and 90Sr from soil-to-potato: Interpretation of the association from global fallout in Aomori to accidental release in Fukushima and Chornobyl

Ceasium-137 and 90Sr are major artificial radionuclides that have been released into the environment. Soil-to-plant transfer of radionuclides is an important route to food contamination. The radionuclide activity concentrations in crops must be quantitatively predicted for estimating the internal radiation doses from food ingestion. In this study, soil and potato samples were collected from three study sites contaminated with different sources of 137Cs and 90Sr: Aomori Prefecture (global fallout) and two accidental release areas (Fukushima Prefecture and the Chornobyl exclusion zone). The 137Cs activity concentrations in the soil and potato samples widely ranged from 1.0 to 250,000 and from 0.048 to 200,000 Bq kg−1 dry weight, respectively. The soil-to-potato transfer factor of 137Cs also ranged widely (0.0015–1.1) and decreased with increasing concentration of exchangeable K. Meanwhile, the activity concentrations of 90Sr in the soil and potato samples were 0.50–64,000 and 0.027–18,000 Bq kg−1 dry weight respectively, and the soil-to-potato transfer factor of 90Sr was 0.023–0.74, decreasing with increasing concentration of exchangeable Ca. The specific activity ratios of 137Cs/Cs and 90Sr/Sr in the exchangeable fraction were similar to those in potatoes, with a factor of 3 in the ±95 % confidence intervals over six orders of magnitude and a factor of 2 in the ±95 % confidence intervals over five orders of magnitude, respectively. According to the data, the accuracy of predicting the activity concentrations of 137Cs and 90Sr in potatoes can be improved by applying the specific activity ratios of 137Cs/Cs and 90Sr/Sr in the exchangeable fraction. This approach accounts for variable factors such as the effects of K and Ca fertilization and soil characteristics. It also emphasizes the benefit of determining the stable Cs and Sr concentrations in potatoes and other crops prior to possible future contamination.

Modeling Radionuclide Transfer from Pasture to Milk in Kisoro, South-western Uganda

Determination of radionuclide transfer from animal feeds to animal products and ingestion transfer rates is important in assessing internal radiation risk to humans who consume the animal products. Seventy-nine (79) pasture samples and milk samples were collected from cattle farms in seven sub-counties. Activity concentrations of radionuclides in the samples were determined using gamma spectroscopy. Transfer ratios of radionuclides to from pasture to milk were calculated. Ingestion transfer rates of radionuclide from pasture to cow were also determined. Radionuclide accumulation to the body of the cow was modeled. Contributions to radiological effects due to accumulation of radionuclides in the body were estimated. Transfer ratios of uranium and thorium from pasture to milk varied from 0.07 to 0.17, and 0.05 to 0.17, respectively. The ingestion transfer rates of uranium varied from 3.110-6 to 7.6 10-6 y l-1 while for thorium, the ingestion transfer rates varied from 2.2 10-6 to 7.5 10-6 y l-1. The contribution to radium equivalent (Bq l-1), annual effective dose equivalent (mSv y l-1), and excess lifetime cancer Risk due to the radionuclide transfer were 0.074, 0.002, and 0.0061 10-3, respectively. Comparing with the safe values of annual effective dose equivalent in foodstuffs of 0.14 mSv y l-1 which translates to excess cancer risk of 0.42 10-3, these contributions to radiological effects only account for about 1.5% of the total safe value of excess lifetime cancer risk, therefore, radionuclide transfer from pasture to milk causes a minimal radiation hazard to the milk consumers in Kisoro District.

Assessment of natural radionuclides in powder milk imported to Erbil Governorate, Kurdistan Region-Iraq

In this study, the activity concentrations of 40K, 232Th, and 226Ra radionuclides were estimated in imported milk powder samples from 40 brands available in local markets in Erbil Governorate, Iraq. The measurements were performed using High Purity Germanium (HPGe) detector. The results indicated that the average activity concentrations of 40K, 232Th, and 226Ra were 241, 0.476, and 1.23 Bq kg−1, respectively, and comparisons were made based on the typical consumption characteristics of powdered milk by Kurdistan residents. In all investigated age groups (2–17 years), the average annual effective doses were below the ICRP-recommended limit of 1 mSv y−1 for public exposure. Radiological hazard parameters were determined based on the measured radioactivity concentrations. The relation between all the determined activities of natural radionuclides and radiological parameters was examined using multivariate statistical analysis techniques such as histograms, descriptive statistics, and Pearson correlation analyses. The cancer risk in all samples was lower than the allowable value of (2.5 × 10−3), while the ingestion dose in two samples was higher than the worldwide acceptable value of (0.29) mSv y−1.

Assessment of Radiological Hazards in Some Foods Products Consumed by the Malian Population Using Gamma Spectrometry

Background: Food consumption is one of the most important routes for radionuclide intake for the public; therefore, there is the need to have a comprehensive understanding of the amount of radioactivity in food products. Consumption of radionuclide-contaminated food could increase potential health risks associated with exposure to radiation such as cancers. The present study aims to determine radioactivity levels in some food products (milk, rice, sugar, and wheat flour) consumed in Mali and to evaluate the radiological effect on the public health from these radionuclides.Materials and Methods: The health impact due to ingestion of radionuclides from these foods was evaluated by the determination of activity concentration of radionuclides <sup>238</sup>U, <sup>232</sup>Th, <sup>40</sup>K, and <sup>137</sup>Cs using gamma spectrometry system with high-purity germanium detector and radiological hazards index in 16 samples collected in some markets, mall, and shops of Bamako-Mali.Results and Discussion: The average activity concentrations were 9.8±0.6 Bq/kg for <sup>238</sup>U, 8.7± 0.5 Bq/kg for <sup>232</sup>Th, 162.9±7.9 Bq/kg for <sup>40</sup>K, and 0.0035±0.0005 Bq/kg for <sup>137</sup>Cs. The mean values of radiological hazard parameters such as annual committed effective dose, internal hazard index, and risk assessment from this work were within the dose criteria limits given by international organizations (International Commission on Radiological Protection and United Nations Scientific Committee on the Effects of Atomic Radiation) and national standards.Conclusion: The results show low public exposure to radioactivity and associated radiological impact on public health. Nevertheless, this study stipulates vital data for future research and regulatory authorities in Mali

Public exposure in the Orenburg region due to natural sources of ionizing radiation. Part 2: Doses to the population of the eastern districts of the Orenburg region

The paper presents the estimated doses to the population of six eastern districts of the Orenburg region, Russia, based on the results of a comprehensive radiation survey conducted in 2019 in 34 settlements with previously found elevated levels of activity concentration of natural radionuclides in tap water from groundwater sources of drinking water supply. It is shown that the average individual annual effective dose due to all natural sources of ionizing radiation in 18 of 34 settlements corresponds to ‘elevated level’ of exposure due to natural sources according to established classification (from 5 to 10 mSv/year), and in another 7 settlements to ‘high level’ (over 10 mSv/year) with radon being the main contributor to the dose. Four settlements of Kvarkensky and Adamovsky districts, where the highest indoor radon concentrations had been found, were selected for a detailed survey, which included measurements of density of radon flux from the soil, radon concentration in soil gas, activity concentration of natural radionuclides in samples of building materials and in soil samples, and activity concentration of radon in tap water from groundwater sources of drinking water supply. Results of the detailed survey proved that the main source of radon in the buildings was the soil gas infiltration; compared to it, the contribution of waterborne radon release was insignificant.

The uncertainty of estimation of doses to the bone marrow from <sup>89,90</sup>Sr due to the variability of the chemical composition and bone density

Dosimetric modeling of radiation transport in skeletal bone tissues using computational phantoms provides the doses of internal exposure to active marrow. Computational phantoms of ICRP are created for reference people with anatomical and physiological characteristics typical of an average individual. The doses calculated with such phantoms will correspond to certain population-average values. Individual variability will introduce a stochastic component of uncertainty into the dose estimation. The objective of this study is to assess the influence of variability of chemical composition and bone density on the results of dosimetric modeling. The phantoms are represented by simple geometry figures filled with trabecular structures and bone marrow and covered with a cortical layer. Radiation transport was simulated using the Monte Carlo method. The dose factors to convert the radionuclide activity concentration to absorbed dose rates in active marrow were calculated assuming uniform radionuclide distribution in the volume of the trabecular and cortical bone. As a result of the numerical experiments, it has been shown that variations in chemical composition do not introduce an error of more than ± 4% into dosimetric modeling. The effect of bone density on active marrow dose formation depends on the size of a phantom. For computational phantoms with linear dimensions exceeding two electron free path lengths (~ 0.44 cm), variability of bone density within ± 3% leads to a similar relative uncertainty of the dose conversion factor. However, for smaller phantoms, bone density variability leads to uncertainties of 6% or 13% for a source deposited in the trabecular or cortical bone, respectively. The results obtained will be used to assess the uncertainty of bone marrow dosimetry, taking into account the uncertainty of all parameters including the variability of morphometric characteristics of bones, the variability of the active marrow distribution in skeletal sites, as well as the uncertainties introduced by model approximations.

Activity concentration of natural radionuclides and transfer factors from soil to vegetable in parts of South South Nigeria

Naturally occurring radionuclide materials are known to exist in soils and is transferred into vegetables and eventually gets into food chain. This work was aimed at determining the activity concentration of these radionuclides in soils and vegetable (fluted pumpkin) and the internal exposure due to the consumption of these materials in the vegetable in parts of South South Nigeria particularly Etim Ekpo Local Government area. The activity concentrations of twenty (20) soil samples and 20 vegetable samples from the farmlands were determined using gamma spectrometry. The activity concentration for 40K ,232Th and 238U from the soil samples ranged from 6.69±0.35 (Bqkg-1) to 168.19 ±8.82 (Bqkg-1) ,0.23 ±0.01 (Bqkg-1) to 5.91 ±0.35 (Bqkg-1) and BDL to 21.53±2.5 (Bqkg-1) respectively. The activity concentration of 40K, 232Th and 238U in the vegetable ranged from (584.23±27.71) Bqkg-1 to (958.67±48.46) Bqkg-1, from (1.84±0.11) Bqkg-1 to (9.72 ±0.56) and from (BDL) to (38.34±3.74) Bqkg-1 respectively. Transfer factors obtained ranged between 12.07±4.7 to 35.35 ±27.9 for 40K, 1.80±0.125 to 5.76 ± 4.31 for 232Th and BDL to 21.05 for 238U. Effective ingestion dose due to the consumption of vegetable from the study area obtained as 0.0021mSvy-1. This value is less than the 0.29mSvy-1 recommended dose limit for the general public; therefore, the consumption of this vegetable could not cause a radiological health effect on its consumers. However negligible or low risk could be minimised when the vegetable is washed and cooked before being consumed. Hence, the results obtained in this study indicate that the activity concentration of the farmland soils and crops represent no significant health risk on the farmers and the consumers of the vegetables.

Assessment of radiation hazard indices due to naturally occurring long-life radionuclides in the coastal area of Barra de Valizas, Uruguay.

The Uruguayan east coast has several mineral resources, which include black sand ores in the Barra de Valizas-Aguas Dulces area. Cancer in Uruguay shows non-homogeneous geographical distribution, with the highest standardized mortality ratio (SMR) in the northeast and east region, which includes the aforementioned area and the town of Barra de Valizas. The activity concentration of natural radionuclides (226Ra, 232Th and 40K) in Barra de Valizas´soil was determined by gamma spectrometry in order to evaluate the radiological hazard for inhabitants and tourists. The outdoor annual effective dose (AEDE), excess lifetime cancer risk (ELCR), and annual gonadal dose equivalent (AGDE) were evaluated for inhabitants with a life expectancy of 77.7years, a 0.2 and 0.5 occupancy factor, and using the conversion coefficients recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The annual effective dose was also evaluated for both summer and fortnight tourists. The radiological hazard indices for Barra de Valizas inhabitants are higher than the worldwide mean and recommended values. This may contribute to Rocha's higher SRM value, although a direct correlation cannot be assured with the epidemiological information currently available. Social, medical and anthropological studies will be carried out in future to provide data and verify this correlation.

Natural radioactivity in select metamorphic and sedimentary rocks of the Opava Mountains (Poland): A comparison between laboratory and in situ measurements of 232Th, 238U, and 40K activities

rocks from the Opava Mountains region (Eastern Sudetes, Poland) as measured in the laboratory and under in situ field conditions. Activity concentrations for 232Th, 238U, and 40K were obtained using an HPGe gamma-ray spectrometry system. Activities for 232Th ranged from 2 to 39 Bq kg−1 as measured in the laboratory and from 5 to 38 Bq kg−1 measured under in situ field conditions. For 238U, the activity concentrations ranged from 4 to 37 Bq kg−1 in the laboratory and from 7 to 42 Bq kg−1 under in situ field conditions. For 40K, activity concentrations ranged from 12 to 820 Bq kg−1 in the laboratory and from 60 to 826 Bq kg−1 under in situ field conditions. Measured activity concentrations were compared with average activity concentrations of radionuclides in similar types of rocks from different global localities. The in situ field measurement and laboratory measurements did not show significant differences indicating that both methods provide reliable 232Th, 238U, and 40K results for different lithologies.

Interpretation of natural radionuclides with respect to the petrological aspects: A study along the coastal region of Azhithala, Southwest coast of India

In the present study the activity concentration of natural radionuclides viz. 40K, 226Ra, and 232Th in the sand samples of coastal regions of Azhithala, Kerala measured using the 5″ × 5″ flat type NaI (Tl) detector. The radiological parameters such as absorbed dose rate (indoor and outdoor), annual effective dose, radium equivalent activity, and excess lifetime cancer risk were measured and compared with the Indian and World average values. The activity concentration of all natural radionuclides is well within the Indian and world average values except for the activity concentration of 232Th. The higher concentration of natural radioactivity in the study area is due to the deposition of weathered zircons or monazites from charnokite rocks. The charnokite group is the predominant lithology of the south the of Kasaragod district. The active erosion by the rivers might be the reason for the presence of the zircons or monazites in the study area. The results of the study are discussed in detail in this manuscript.

137Cs in Soils from İstanbul (Turkey) Sampled 35 Years After Chernobyl

The artificial 137Cs radionuclide dispersed into the atmosphere as a consequence of the Chernobyl accident. As a result of the explosion, radioactive pollution occurred in the Black Sea and Thrace region. In the present study, to assess the risks associated with the exposure due to Chernobyl fallout, artificial 137Cs radionuclide was analyzed in collected surface soil samples from the Anatolian region of Istanbul, in Thrace Region of Turkey by a gamma-ray spectrometer equipped with HPGe. The artificial 137Cs radionuclide activity concentrations range from <0.07 to 9.95 ± 0.19 Bq kg−1 d.w. in soil samples. To estimate the radiological hazard resulting from fallout 137Cs were calculated. The annual effective dose rate ranges from 0.003 to 0.37 μSv y−1. Statistical analyses were carried out to understand the distribution of 137Cs activity concentration.