Activity Concentrations Of 232Th Research Articles

Assessment of Natural Radioactivity and Associated Radiological Indicators in Water and Surface Soils Around Beta Glass Plc and Its Environs, Ughelli, Delta State, Nigeria

A radiometric assessment was conducted around Beta Glass plc using sodium iodide detector (3×3-inch NaI (TI)). The study collected 14 soil and 13 water samples from June to July 2022, analyzing radioactivity concentrations of 40K, 238U, and 232Th. The mean specific activity concentrations of 40K, 238U, and 232Th were 184.00±29.73 Bqkg-1, 14.55±2.50 Bqkg-1, and 8.60±1.04 Bqkg-1, respectively, in soil samples, but these elements' concentrations in water were 27.429±5.633 BqL-1, 6.661±1.421 BqL-1, and 2.518±0.361 BqL-1, respectively. The average activity concentrations of 40K, 238U, and 232Th were lower than the safe limit, and the corresponding radiation hazard indices for soil samples were all below the UNSCEAR-recommended acceptable limits. The mean activity concentrations of radionuclides in water samples were higher than the UNSCEAR's recommended international limits for 40K, 238U, and 232Th. Nonetheless, elevated radiological health hazards imply that cumulative dosages may cause cancer, even though these values might not pose an immediate health concern to the local community's people or the workforce.

Risk assessment due to natural radioactivity of stone dust and crushed stone Commercialized in construction stores in the state of Rio de Janeiro

A systematic study of the distribution of the Naturally Occurring Radioactivity in stone dust and crushed stone, has been carried out with an objective of establishing reliable baseline data on the radiation level and hence to evaluate hazard indices approach and the production of radioactive heat (RHP) due to radiation exposure to the workers and to the inhabitants of the studied area. Twenty-six samples have been collected from different locations in the State of Rio de Janeiro (Brazil). To calculate the specific activity, gamma ray spectrometry and a detector of High Purity Germanium (HPGe; Canberra, 30% relative efficiency) was used. The activity concentration of 238U, 226Ra 232Th and 40K ranged from 29.3 ± 18.6 to 206.8 ± 21.5 Bq kg−1, 30.3 ± 1.0 to 134.3 ± 1.8, 27.9 ± 0.7 to 86.2 ± 0.9 Bq kg−1, and 734.9 ± 35.1 to 1204.8 ± 53.5 Bq kg−1, respectively. The mean values of the Iex, Iin, Iγ, Iα, AUI, IRP112Rn, IPA, IPI and IYu indices were 0.68 ± 0.09, 0.92 ± 0.12, 0.93 ± 0.12, 0.43 ± 0.07, 0.88 ± 0.20, 1.25 ± 0.21, 0.34 ± 0.05, 0.75 ± 0.10, 0.63 ± 0.08 and 34. ± 6.31, respectively. The average radioactive heat production (RHP) of 2.01 ± 0.28 μ Wm−3 was above the values found in the literature, which may contribute to the heat flow in the study area because the raw materials that make up the samples showed a high value of environmental radioactivity. The Brazilian Hazard Index to assess the radiological risk of crushed stone and stone dust was created and the average value was 0.74 ± 0.10, a value below 1, which means only moderate control over the use of these materials, with no indication of restriction to the its use.

Natural Radionuclides Concentrations and Associated Radiation Hazard of Some Building Rocks Used in Taiz City, Yemen

Building materials comprise a diverse range of natural rocks that contain varying mineral components including radionuclides. Gamma spectrometry-based high-purity Germanium detectors were utilized to measure the activity concentrations of natural radionuclides: Radium-226 (226Ra), Thorium-232 (232Th), and Potassium-40 (40K) in various building rock samples found within and surrounding Taiz city. The activity concentrations of 226Ra, 232Th, and 40K vary from 27.79 ± 0.77 to 234.49 ± 3.13 Bq.kg-1, 25.82 ± 0.40 to 415.31 ± 2.47 Bq.kg-1, and 457.91±2.61 to 1139.56 ± 5.43 Bq.kg-1 with overall average value of 71.55 Bq.kg-1, 93.87 Bq.kg-1, 966.88 Bq.kg-1 respectively, these values were higher than the permissible thresholds. Furthermore, several radiation hazard indices were estimated including the radium equivalent (Raeq), the external hazard index (Hex), the internal hazard index (Hin), the gamma level index (Iɤ), the dose rate(Dɤ), the annual effective dose equivalent (AEDE), the excess lifetime cancer risk (ELCR), and the annual gonadal dose equivalent (AGDE). The findings illustrated that Basalt rocks have the minimum values of radiation hazard indices while the Himatite rocks have the maximum values of radiation hazard. The average values of radiation risks for most of building rocks fall below the recommended limits for safety. Based on the Radiation hazard indices of building rock samples, it can be concluded that with the exception of hematite rocks, all the examined rocks are considered safe for use in construction materials and pose non-significant radiation risks. The awareness about natural radioactivity levels of building rocks is critical for planning and performing strategies in radiation safety of buildings.

Assessment of radionuclides in the soil of Bonny Local Government Area Of Rivers State, Nigeria and evaluation of radiological risk

Twenty Samples each of soil from Bonny LGA, Rivers State, Nigeria were analyzed using NaI(IT) gamma detector to estimate radiation hazard due to the anthropogenic sources. The activity concentration of 232Th was found to be in the range 18.78 – 397.13 BqKg-1, 40K in the range 43.72 – 390.62 BqKg-1 and 226Ra in the range 10.77 – 57.84 BqKg-1 all in soil. These results were used to calculate the radiological hazard parameters including the Annual Gonadal Equivalent Dose. The calculated gamma exposure rates ranged between 10.00 – 270.79 nGyh-1 while the average value of the Excess Lifetime Cancer Risk (ELCR) was found to be 0.38 x 10-3 for soil which is higher than the world average of 0.29 x 10-3.

Geophysical survey and radiometric assessment of aquifer strata and vulnerable groundwater quality of Ukwuani Ommunities in Delta State

The study assessed the aquifer strata and groundwater quality of Obeti, Umuaja, and Ebedei communities of Ukwuani, Delta State, Nigeria using electrical resistivity technique and sodium iodide [Na(TI)] detector. The electrical resistivity technique revealed that lithology has five to six geoelectric strata, which ranged from topsoil to clay formations with thickness of 0.6 to 6.0 m sits and aquifer resistivity range of 182.1– 6032.0 Ωm with depth of 29–70 m. These ranges indicate significant changes in the aquifer level and sufficient reservoirs for groundwater. To assess the activity concentrations of 238U, 232Th and 40K at the aquifer depth of 29–70 m groundwater, a total of fifteen groundwater samples were collect for analysis and the mean results are 9.00±1.24Bql−1, 4.82±2.95Bql−1 and 57.93±4.20Bql−1 respectively. These results are all above world threshold limits. However, the computed mean radiological health risk values for radium equivalent (Raeq), representative index (Iy), external hazard index (Hin), internal hazard index (Hex), absorbed dose rate (D), annual effective dose equivalent (AEDE), outdoor and indoor, and excess lifetime cancer risk (ELCR) outdoor and indoor are 20.35±5.78 Bql−1, 0.15mSvy−1, 0.056mSvy−1, 0.08mSvy−1, 9.55μGyh−1, 11.71mSvy−1, 46.84mSvy−1and 0.04×10−3, 0.16×10−3 and 0.20×10−3 for the addition of (ELCR) outdoor and indoor respectively. The computed mean radiological values are below world threshold limits. Hence, the studied communities’ drinking groundwater is safe radiologically. It is advised that government, oil and gas operators and individuals should drill above 30 m depth for quality groundwater and should be treated before usage. These values will serve as baseline data.

Evaluation of radioactivity and radiological parameters in soil samples in Isparta, Türkiye

In the city centre of Isparta, located in the southwestern part of Türkiye, indoor radon concentrations and gamma dose rate levels were observed above the world and country averages. For this reason, the determination of the natural radioactivity levels in soil samples of Isparta province is of great interest. In the present study, the activity concentrations of radionuclides (namely 226Ra,232Th, 40K and 137Cs) were investigated in the soil samples collected from 72 different points including the city centre and 12 towns of Isparta by using a gamma spectrometer with a high-purity germanium (HPGe) detector. The activity concentrations of 226Ra,232Th, 40K and 137Cs radionuclides in the samples were found in the range of 4.08 ± 0.39–69.84 ± 1.43 Bqkg−1, 2.63 ± 0.28–65.66 ± 1.41 Bqkg−1, 44.48 ± 3.17–452.38 ± 9.65 Bqkg−1 and 0.28 ± 0.18–19.10 ± 0.61 Bqkg−1 respectively. The averages of all the measurements were determined as 15.69 ± 0.72 Bqkg−1 for 226Ra, 15.40 ± 0.78 Bqkg−1 for 232Th, 210.60 ± 6.22 Bqkg−1 for 40K and 3.44 ± 0.31 Bqkg−1 for 137Cs. Although these values were below the country and world averages, it was revealed that the 226Ra and 232Th activity concentrations in the city centre exceeded the national and world averages. In addition, radiological risk maps of the analysed radionuclides were produced for the first time, covering all towns within the Isparta province. To evaluate the radiological hazards resulting from natural radionuclides, external hazard index (Hex), absorbed dose rate (D), annual effective dose equivalent (AEDE), male and female lifetime cancer risk (LCR) values were also calculated. The outcomes of this study revealed that all the radiological parameter averages for Isparta were lower than the world and country averages but the calculation results for the city centre displayed the opposite of this situation except for the external hazard index.

Assessment of natural radioactivity levels and hazard indicators in Tarakeshwor Municipality, Nepal through in-situ technique and multivariate analysis

The evaluation of primordial radionuclide concentrations in rapidly urbanized and concrete-laden areas through the importation of construction materials from various regions of Nepal is both important and essential. This study utilized a portable gamma-ray spectrometer (PGIS 2) to analyze the distribution of three natural radionuclides: uranium (238U), thorium (232Th), and potassium (40K) in Tarakeshwor Municipality, Kathmandu, Nepal. The measured dose rates ranged from 70.22 nSv hr−1 to 163.66 nSv hr−1, with an average of 124.65±20.29 nSv hr−1, surpassing the global average of 59 nSv hr−1. The activity concentrations of 40K, 238U, and 232Th exceeded global averages, indicating relatively higher natural radioactivity concentrations in the region. Specifically, the average values for 40K, 238U, and 232Th were 935.26±172.30 Bq kg−1, 80.47±15.53 Bq kg−1, and 80.44±18.58 Bq kg−1, respectively. The calculated radium equivalent (Raeq) ranged from 132.26 to 351.22 Bq kg−1, and the annual gonadal equivalent dose (AGED) varied from 372.61 to 1028.81 μSv yr−1. The annual effective dose rates for indoor and outdoor environments were 0.54±0.09 mSv yr−1 and 0.15±0.03 mSv yr−1, respectively, both exceeding the global average. The representative level index (RLI) within the study area averaged 1.96±0.32, indicating an elevated radiation risk. The excess lifetime cancer risk (ELCR) values for outdoor and indoor environments were 0.52×10−3 ±0.09 ×10−3 and 1.87 ×10−3 ±0.31×10−3, respectively, surpassing the world average. Additionally, external hazard indices (Hex) ranged from 0.36 to 0.59, while internal hazard indices (Hin) ranged from 0.38 to 1.20, both indicating values higher than UNSCEAR recommendations. These findings underscore the necessity for further experimental analysis employing ex-situ equipment. The data generated in this study can provide a valuable baseline for future assessments and interventions in radiation risk management guidelines within the country.

Gamma ray spectrometric analysis and assessment of radiation hazards in soils of Mbeere North region, Kenya.

This study used gamma ray spectrometry to determine the radiological safety of construction soil sampled randomly from Mbeere North region, Kenya. The mean activity concentration of 232Th, 238U, and 40K was 149.7±2.8 Bqkg-1, 88.3±2.4 Bqkg-1, and 490±35 Bqkg-1, respectively. These averages exceed the world average for all the radionuclides. The radionuclides were non-uniformly distributed, with higher concentrations along the slopes and on the feet of the hills. The mean absorbed dose rate, indoor and outdoor annual effective dose, radium equivalent, external hazard index, and internal hazard index were 157.9±4.4 nGh-1, 0.58±0.02 mSvy-1, 0.39±0.01 mSvy-1, 340.7±9.2 Bqkg-1, 0.92±0.02 and 1.14±0.03, respectively. Among the radiation safety indicators, only the average internal hazard index exceeded slightly the acceptable safe limit. Therefore, soils of Mbeere North region are radiologically safe for use in brick making and construction of human habitats.

Investigation of natural radionuclides and radiation shielding potential of some commonly used building materials in Northwestern Nigeria

This study assessed the gamma-ray shielding potential of clay, sand, gypsum and kaolin commonly used as a building material in Northwestern, Nigeria. The radiological status of the samples was first evaluated by determining the activity concentrations of 238U, 232Th and 40K using NaI (Tl) detector after which elemental composition and mass density were determined using Neutron Activation Analytical Technique. After which the mass attenuation coefficients (MAC), linear attenuation coefficients (LAC), half value layer (HVL), tenth value layer (TVL), and effective atomic number (Zeff) were determined experimentally and theoretically using standard point sources of 137Cs and 60Co photon peaks (0.662 and 1.332, 1.173) MeV and Py-MLBUF software. The activity concentrations were found to range from 51 to 59 Bq kg−1 with a mean value of 59 Bq kg−1 for 238U, 24 to 27 Bq kg−1 with a mean value of 29 Bq kg−1 for 232Th, and 219 to 247 Bq kg−1 with a mean value of 247 Bq kg−1 for 40K which were about within the world recommended values of 33, 45 and 420 Bq kg−1 respectively. The results of the elemental compositions show that Si, Al, K, Fe, and Ba in clay and sand samples have concentrations in the range of 36.83–78.48%, 1.92–26.05%, 6.33–21.96%, 2.39–19.09%, and 0.09–1.44%, respectively, while in kaolin and gypsum, results revealed that Si, Al, K, Fe, and Ca range between 0.34 and 65.52%, 1.14–35.82%, 0.00–12.12%, 0.00–5.77%, and 0.00–96.6%, respectively. However, the concentrations of other elements such as Mg, Ti, Mn, Zn, Na, and Ba varied significantly with the samples. The results showed that clay has an average density of 1.96 g/cm3, sand has 2.32 g/cm3, kaolin has 2.63 g/cm3, and gypsum has the highest density with a value of 2.66 g/cm3 compared to other samples. During the measurements, a thallium-activated sodium-iodide NaI (TI) detector was used. A narrow beam transmission geometry condition was adopted for the measurements to ensure minimal scattered radiation. Absorption and attenuation of gamma beams as a function of sample thickness against gamma energy generally exhibit an increasing gamma ray behaviour as the sample thickness increases from 1 to 3 cm. The results showed that the gypsum, kaolin, sand, and clay were capable of attenuating 63.5%, 61.5%, 58.4%, and 44.2 of gamma-ray photons of energy 0.662 MeV at 3 cm thickness %, respectively, and 40.6%, 32.9%, 30.6%, and 27.3% of gamma energy 1.332 MeV at 3 cm thickness, respectively. The results showed that MAC, LAC, and Zeff of all the samples decreased with an increase in photon energy, while those of HVL and TVL increased. The experimental results for all the gamma-ray shielding parameters were found to be in good agreement with the theoretical values obtained using Py-MLBUF. The results have shown that all the samples have similar photon attenuation behaviours; however, gypsum has the best shielding potential than kaolin and this is attributed due to its highest density value.

Evaluation of radioactivity concentration in farm fresh milk and concomitant dose to consumer

In this study, activity concentrations of natural radionuclides in 28 raw milk samples collected from different dairy farms in Dhaka city of Bangladesh were measured using a high-purity germanium (HPGe) detector for the first time. The activity concentration of 226Ra, 232Th, and 40K in the investigated fresh milk samples ranged from BDL (Below detection level) to 26 ± 1.6 Bq/kg, BDL to 11.7 ± 3.3 Bq/kg and 101 ± 17 to 384 ± 32 Bq/kg, respectively. No artificial radionuclides were found in the investigated samples. Present results show inline within the range of available data in the literature. Annual committed effective doses were estimated following the consumption characteristics of raw milk by city population, values are found within the limiting range recommended by international organizations due to consumption of foodstuffs. Additionally, real-time gamma-ray dose rate in the farms/sampling locations was found in the range of 0.12 ± 0.01–0.20 ± 0.01 μSv/h by using a digital gamma survey meter (Gamma Scout) and the calculated maximum annual effective dose due to outdoor absorbed dose was found to be 0.25 mSv/y, which shows lower than the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended limit of 2.4 mSv/y. This study indicates that the concentration of radionuclides in the farm fresh milk of Dhaka city does not pose any unwanted risk to public health, and it is safe to consume by both children and adults with the current intake level.

Radiological Assessment and Potential Health Risks of Tailings from Komu, Southwestern Nigeria

There are reports that radionuclides found in mining tailings pose significant challenges to the natural environment and cause health risks to humans. The study investigated the levels of activity concentrations of 226Ra, 232Th and 40K radionuclides, as well as radiological hazard indices in tailings sourced from Komu, a community emblematic of mining activities in the Southwest of Nigeria. Thirty (30) tailing samples were collected and analysed by a High-purity Germanium (HpGe) detector. The results revealed high activity concentrations of these radionuclides exceeding global averages and indicating potential health risks. The activity concentration of 226Ra ranged between 312.07 and 851.14 Bq/kg, with an average of 652.86 Bq/kg. Similarly, the activity concentration of 232Th ranged between 33.31 and 160.10 Bq/kg, with an average of 116.26 Bq/kg. In addition, the activity concentration of 40K ranged between 96.11 and 1184.65 Bq/kg, with an average of 717.53 Bq/kg. The radiological hazard indices considered in this study exceeded the internationally accepted safety limit for building construction materials. These findings indicate heightened exposure risks, emphasizing the need for regulatory measures to mitigate hazards associated with tailings sourced from Komu, particularly for building construction purposes.

Assessing the radiological hazards due to radionuclides in sediments and tailings around Kilembe copper mines, Western Uganda

ABSTRACT Copper mining in Kilembe Valley, Western Uganda, between 1956 and 1982 resulted in multiple tailing sites, raising concerns about potential increases in the natural background radiation. In this study, the radioactivity concentrations of 226Ra, 232Th, and 40K in 31 sediments and tailing samples from the Kilembe copper mines area were determined using HPGe-based gamma spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K in sediment samples were 38.6 ± 8.9, 37.4 ± 7.8, and 708.0 ± 147.3 Bq kg−1, respectively. While in tailing samples, the mean values were 171.3 ± 31.7, 34.8 ± 14.9, and 792.4 ± 208.2 Bq kg−1, respectively. These values exceeded global averages of 35, 30, and 400 Bq kg−1 for 226Ra, 232Th, and 40K, respectively. To assess the radiological hazards due to radionuclides in sediments and tailings, several parameters such as the radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), gamma representative index (Iγ), absorbed dose rate (D), total annual effective dose (Etot), and total excess lifetime cancer risk (ELCRtot) were determined. In sediments, most of these hazard parameters were above the world’s average values, except Raeq, Iγ, Hex, and Hin. While in tailings, all the hazard parameters surpassed the global average values except Raeq and Hex. Pearson correlation coefficient and hierarchical cluster analysis showed that 226Ra was the main contributor to the assessed radiological hazards. The study suggests potential radiological risks linked to natural radioactivity from sediments and mine tailings, especially when used as building materials.

Evaluation of Radioactivity Levels in Soil Samples from Assosa City in Benishangul Gumuz Region, Ethiopia

The specific activity concentrations of naturally occurring radionuclides in soil samples collected from suburban areas of Assosa City was measured using a High purity Germanium (HPGe) detector. The average specific activity concentrations of 238U and 232Th exceed the recommended safe value of 35.0 and 30.0 Bq kg−1, respectively. For 40K, the average activity concentration is below the recommended safe value of 400.0 Bq kg−1. The calculated mean value of the absorbed dose rate is 72.8 ± 3.72 nGy h−1 which exceed the recommended safe value of 59 nGy h−1. The calculated mean annual effective dose equivalent values for indoor and outdoor are 2.11 ± 0.1 mSv y−1 and 0.52 ± 0.02 mSv y−1, respectively. The calculated mean values of the internal hazard index, external hazard index, and gamma index are 0.43 ± 0.013, 0.56 ± 0.01, and 0.5 ± 0.01, respectively, and those values are below the recommended safe value of one. The mean value of excessive lifetime cancer risk is above the threshold value of 0.29 × 10−3. From this study, it is recommended that Assosa soil needs further investigations.

Natural radionuclides and radiological risk assessment in the stream and river sediments of a high background natural radiation area Kanyakumari, India.

The Kanyakumari coast is known to be a high background natural radiation area due to the placer deposits of heavy minerals such as ilmenite, monazite, and rutile. The Kanyakumari river sediments that could be the source of the elevated amounts of natural radionuclides in the coastal sands have been studied in this paper. The activity concentrations of primordial radionuclides 226Ra, 232Th, and 40K were determined using high-purity germanium (HPGe) gamma-ray spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K were found to be 75Bqkg-1, 565Bqkg-1, and 360Bqkg-1, respectively. The mean absorbed dose rate was 395 nGy h-1. Radiological hazard parameters were studied and compared with the world average values. The contribution of 232Th to the total dose rate was found to be higher than that of the two other radionuclides. The high mean ratio of 232Th/226Ra suggested an enrichment of 232Th and the occurrence of 226Ra leaching due to an oxidizing environment. Principal component analysis (PCA) was carried out for the radionuclides in order to discriminate the source of the sediments. This study provides new insights into the distribution of natural radionuclides in sediments of rivers and streams.

Survey of Natural Radioactivity of Soil and Rock Samples and their Radiological Implications to Human Health in Ugwuele Quarry Mining Site, Uturu, Abia State, Nigeria

This work measured the activity concentration of natural radionuclides 238U, 232Th and 40K in soil and rock samples collected in Ugwuele mining site and it surrounding communities in Uturu, Abia state, Nigeria. Fifteen different samples collected were analyzed. A NaI (Tl) spectrometry detector system was adopted for this research. The results obtained were used to estimate the radiological implication of the quarry mining in the study area. The average gamma activity obtained for 238U, 232Th and 40K in soil were 53.39 ± 3.08, 76.79 ± 9.66 and 1061.02 ± 15.72 Bq/kg respectively and 55.09 ± 5.71, 90.96 ± 16.10 and 1281.78 ± 6.38 Bq/kg respectively for rock samples. The calculated radiological hazard indices from Absorbed dose rate, Annual effective dose, Radium equivalent, internal hazard index and External hazard index gave 120.25 nGy/h, 0.147 msv/yr, 247.5 Bq/kg, 0.833 and 0.687 respectively. The average dose rate was higher than the recommended limit. Therefore, soil and rock materials found in Ugwuele could increase the radiological hazards on miners and residents of the area due to long time cumulative exposure.

Using radial basis artificial neural networks to predict radiation hazard indices in geological materials.

The estimation of exposures to humans from the various sources of radiation is important. Radiation hazard indices are computed using procedures described in the literature for evaluating the combined effects of the activity concentrations of primordial radionuclides, namely, 238U, 232Th, and 40K. The computed indices are then compared to the allowed limits defined by International Radiation Protection Organizations to determine any radiation hazard associated with the geological materials. In this paper, four distinct radial basis function artificial neural network (RBF-ANN) models were developed to predict radiation hazard indices, namely, external gamma dose rates, annual effective dose, radium equivalent activity, and external hazard index. To make RBF-ANN models, 348 different geological materials' gamma spectrometry data were acquired from the literature. Radiation hazards indices predicted from each RBF-ANN model were compared to the radiation hazards calculated using gamma spectrum analysis. The predicted hazard indices values of each RBF-ANN model were found to precisely align with the calculated values. To validate the accuracy and the adaptability of each RBF-ANN model, statistical tests (determination coefficient (R2), relative absolute error (RAE), root mean square error (RMSE), Nash-Sutcliffe Efficiency (NSE)), and significance tests (F-test and Student's t-test) were performed to analyze the relationship between calculated and predicted hazard indices. Low RAE and RMSE values as well as high R2, NSE, and p-values greater than 0.95, 0.71, and 0.05, respectively, were found for RBF-ANN models. The statistical tests' results show that all RBF-ANN models created exhibit precise performance, indicating their applicability and efficiency in forecasting the radiation hazard indices of geological materials. All the RBF-ANN models can be used to predict radiation hazard indices of geological materials quite efficiently, according to the performance level attained.

Radiometric survey of sediments and health risk assessments from the southern coastal area of Delta State, Nigeria

Over the years, the release of potential radiological components around the oil exploration environment has increased with potential health implications.Yet; the mechanism and health associated assessment have remained fuzzy to most experimental scientists. The current study determines the activity concentration of radionuclides in sediments and the corresponding health risk assessments from the hydrocarbon exploration environment of the southern coastal area of Delta State, Nigeria. A Sodium-iodide NaI(Tl) detector, with a well-calibrated multichannel analyzer (MCA) to ensure efficiency and energy was utilized. A total of seventy-five sediment samples (Five sediment samples each per community) were collected from the southern coastal area of Delta State, Nigeria. The mean activity concentrations of 40K, 238U, and 232Th of the sediment samples were 3361.48 ± 194.26 Bqkg−1, 40.11 ± 16.17 Bqkg−1, and 45.73 ± 19.27 Bqkg−1 respectively. The obtained mean values exceeded the world standard limit of 400 Bqkg−1, 35 Bqkg−1, and 30 Bqkg−1 respectively. Also, the computed mean radiological health hazard risk of radium equivalent activity (Raeq), representative level index (Iyr), external hazard index (Hex), internal hazard index (Hin), absorbed gamma dose rate (D), annual effective dose equivalent outdoor and indoor (AEDE) and lifetime cancer risk (ELCR) values are 363.94 ± 32.37 Bkgl−1, 2.9657 Bkgl−1, 0.9839, 1.0919, 175.82 nGyh−1, 2.1556 mSvyr−1, 0.8625 mSvyr−1, and 7.5447 mSvyr−1 respectively. The values were found to be slightly higher than the world standard limit. Therefore, the residents that are using the sediments of the southern coastal area for the construction of buildings as well as dwelling in houses built with such sediments are exposed to these radiological materials. This may pose a radiological health risk concern. The obtained results will serve as radiation and radiological baseline data for sediments of the southern coastal area of Delta State, Nigeria.

Gamma Ray Spectroscopy Analysis of Sediments of Coastal Areas in Ennore, Tamil Nadu

Objectives: This research focuses on the determination of the natural radionuclides radium, thorium, and potassium in the twenty-six sediment samples collected at the sea, beach, and creek regions of Ennore Port. Methods: The activity concentrations of 226Ra, 232Th, and 40K were determined using gamma ray spectrometry with a high-purity germanium (HPGe) detector. Findings: The average activity concentrations of 226Ra, 232Th, and 40K were in the descending order of 40K (397.58 Bq kg-1) > 232Th (65.83 Bq kg-1) > 226Ra (18.28 Bq kg-1). The estimated average values of radiological parameters such as radium equivalent activity (143.04 Bq kg-1), absorbed dose rate (64.91 nGy h-1), annual effective dose equivalent (0.32 mSv y-1), and external hazard index (0.39) were lower than the respective world average values, reported by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000). Moreover, the representative level index and annual gonadal dose equivalent were slightly higher than the world average value. Hence, this research proved that the study area is radiologically safe for humans and the environment. Novelty: A location and sample collection-based novelty is approached to carried out the work. Sea sediments were also collected along with samples from creek and beach regions in order to examine the dispersion of natural radionuclides from land to marine environments. The samples from the beach and creek regions were collected using a Peterson grab sampler. Especially in the sea region, the samples were collected using a Van Veen grab sampler at a depth of 4 m and a distance of 10 m parallel to the shoreline. Keywords: Natural radioactivity, Sediment, Ennore, Gamma ray spectrometry, HPGe detector, Radiological parameters

Naturally occurring radioactive materials (NORM) concentration and health risk assessment of aerosols dust in Nicosia, North Cyprus

This study was carried out to evaluate the distribution of naturally occurring radioactive materials (NORM) and radiological risk indexes in aerosol dust in Nicosia, Cyprus utilizing a high-resolution HPGe gamma-spectrometry. The activity concentrations of 226Ra, 232Th, and 40K in the selected aerosol dust samples ranged from 25.9–52.4, 21.7–46.3, to 471–1302 Bq kg−1, respectively. The average activity concentrations of 40K were found to be above the Earth's crust average. The internal and external hazard indexes are well below the acceptable limit in most dust samples. All investigated samples met the exemption dose limit of 0.3 mSv y−1.

Assessment of Activity Concentrations and Soil-to-Plant Transfer Factors of Natural Radioactivity in Rice Plant Components grown in Kano State, Nigeria

Transfer Factor (TF) depicts the percentage or fraction of natural radioactivity in the soil that is absorbed by different parts of a plant which are eventually transferred, directly or indirectly, to man during ingestion. Activity concentrations of primordial radionuclides were determined in farm soil and rice plant components (root, stem, leaf and seed) in six Local Government Areas (Bagwai, Bunkure, Dambatta, Garko, Kura and Wudil) renowned for production of rice in Kano State, Nigeria, using gamma-ray spectrometry method with sodium iodide scintillation detector. The mean activity concentrations of 40K, 238U and 232Th were: 509.51, 27.75, and 12.26 Bq.kg-1 correspondently in soil; 227.40, 14.24, and 5.19 Bq.kg-1 correspondingly in seed; 935.53, 32.73, and 7.29 Bq.kg-1 accordingly in leaf; 803.65, 16.72, and 6.76 Bq.kg-1 respectively in stem; and, 408.91, 30.03, and 10.31 Bq.kg-1 correspondingly in root. The mean concentrations of 40K reported in soil were greater than the world average of 400 Bq.kg-1, while those of 238U and 232Th were less than the world mean values of 35 Bq.kg-1 and 30 Bq.kg-1 respectively. The estimated mean of TFs of 40K, 238U and 232Th were: 0.52, 0.61, and 0.43 respectively in the seed; 1.95, 1.45, and 0.69 respectively in leaf; 1.72, 0.75, and 0.64 correspondingly in the stem; and, 0.85, 1.27, and 0.76 accordingly in the root. Except for a few plant samples where BDL were recorded for 238U and 232Th, all values of TFs were greater than the recommended values of 4.9 x 10-3 and 2.1 x10-4 given for 238U and 232Th...