Radiological Hazard Research Articles

Soil-to-organic Sangyod rice grain transfer factors (TF values) of natural and anthropogenic radionuclides in Phatthalung province, Thailand

The specific activities of natural (40K 226Ra and 232Th) and anthropogenic (137Cs) radionuclides in paddy soil and organic Sangyod rice grain were measured and analyzed in this study with an aim to determine the soil-to-organic Sangyod rice grain transfer factors (TF values) of all required radionuclides in Don Pradu sub-district, Pak Phayun district in Phatthalung province in the south of Thailand. The high purity germanium (HPGe) detector and gamma-ray spectrometry analysis system which were installed and used in advanced laboratory at TINT were used to conduct experiments to measure and analyze of all required radionuclides in this research. The average concentrations of 40K 226Ra, 232Th, and 137Cs in paddy soil were found to have a value of 657.30 ± 23.03, 180.01 ± 4.39, 162.02 ± 3.84 and < 1.81 Bq/kg respectively while in organic Sangyod rice grain, their values were 24.11 ± 2.01, 0.28 ± 0.07, 0.17 ± 0.06 and 0.10 ± 0.03 Bq/kg respectively. For TF values were calculated and found to be 0.037, 0.002, 0.001, and 0.055 for 40K, 226Ra, 232Th, and 137Cs, respectively. Furthermore, four important radiological hazard indices which are gamma-absorbed dose rate (D), radium equivalent activity (Raeq), external hazard index (Hex) and annual external effective dose rate (AEDout) were also evaluated by using the average values of 40K, 226Ra and 232Th. In addition, by using the AEDout value, the excess lifetime cancer risk (ELCR (outdoor)) in paddy soil in the study area would be also studied, evaluated and presented. Moreover, the evaluated TF values of required radionuclides were higher than that reported by the International Atomic Energy Agency (IAEA) in 2010 but the values were much lower than those in the study in Malaysia.

Natural radioactivity level in graphite samples from the Cătălinul deposit, Parâng Mountains, Romania: sources identification and radiological risk assessment

Twenty graphite samples (amorphous and crystalline flake types of graphite) were collected from the ore storage of the Catalinul deposit and, the 238U, 232Th, 40K naturally occurring radionuclides have been investigated by gamma-ray spectrometry. The mineral contents of selected graphite samples were examined using a scanning electron microscope (SEM). The radiological hazard parameters: radium equivalent activity (Raeq), absorbed gamma dose rates in air (DR), and external hazard index (Hex) were calculated and compared with international safety limits. Radiometric data showed average specific activities for 238U, 232Th and, 40K of 80.40, 49.69 and, 124.21 Bq kg–1 for amorphous graphite respectively, 38.53, 76.25 and, 241.12 Bq kg–1 for flake graphite. Zircon, rutile, uraninite, coffinite, urano-thorite, and monazite are the main radioactive element bearing minerals. The mean of the radiological hazard parameters: Raeq – 262.22 (Bq kg–1), DR – 123.72 (nGy/h), and 0.7 – Hex do not exceed the recommended values by UNSCEAR.

In-situ radiological classification and characterization methodology of activated cables in particle accelerators

The estimation of induced radioactivity and radiological classification of activated material is necessary throughout the life cycle of the Large Hadron Collider (LHC) accelerator. As part of the upgrade to High-Luminosity LHC (HL-LHC), radiation protection assessments need to be performed in order to estimate the radiological hazard during the dismantling activities of the LHC cables. The proposed In-situ radiological classification and characterization of the activated cables relies on validated FLUKA.CERN Monte Carlo simulations and analytical computations. The objective is to establish a methodology that allows clearing the material from regulatory control according to the Swiss Radiation Protection Legislation using the total gamma counting (TGC) analysis technique for an envelope set of activation scenarios. The study also includes a preliminary benchmark of the FLUKA geometry model and physics models based on gamma spectrometry laboratory analyses of representative samples.

NATURAL RADIOACTIVITY LEVELS AND RADIOLOGICAL HAZARDS INDICES OF SOIL SAMPLES FROM SELECTED MINING SITES, DANGE-SHUNI, SOKOTO STATE, NIGERIA

Elevation of environmental radioactivity is a growing concern that requires monitoring and measurement via nuclear analytical procedures and have been conducted from Dange-Shuni in this study. The unabated mining activities whose motive is to constantly keep industries running on locally sourced minerals and raw materials often leave the host communities with heavy burden of radioactivity impacts that have be monitored in this study. this should explicitly and clearly state main objectives of the work. Hyper Pure Germanium detector coupled to a Multi-Channel Analyzer (MCA) was used for gamma-ray spectrometry to ascertain the activity concentration results of ,,in 15 packs of homogenized soil samples collected from mining sites, Dange-Shuni LGA, Sokoto State, Nigeria. Mutually exclusive and collectively exhaustiveness approach of sampling was adopted in order to overcome the limitations of large and diverse nature of mining localities terrain. Results obtained from gamma-ray spectroscopy reveals a range of 30.72.9 to 95.67.2, 30.72.9 to 95.67.2 and 499.2051.5 to 971.2421.5 for ,and respectively. The mean values were calculated to be 58.04, 54.5 and 767.62 respectively. The radiological hazards of , , , , , and were obtained for the results of activity concentration ascertained in this study. The results were found in elevations to the world mean values in comparison which is an implication of dangers of environmental radioactivity to the generality of the dwellings. These results are in good agreements with previous studies and hence, suggests for similar investigation to be conducted.

Assessment of radionuclide distribution and associated radiological hazards of soils in Mayo-Belwa, Adamawa state

Mayo-Belwa Local Government Area has been reported to have deposits of Uranium; hence this study was carried out to measure radionuclide activities in Mayo-Belwa soils and to monitor their potential impact on human health. Soils from a depth of 10 cm were collected from each location, using CANBERA NaI (Tl) detector, the activity concentration of radionuclides of 10 soil samples was measured. The radionuclide concentration ranged between 72.7069 - 116.8504 Bq.kg−1 for 238U (measured by 226Ra activity), 148.9168 -981.4994 Bq.kg−1 for 40K and 22.3332 - 108.5203 Bq.kg−1for 232Th. The gamma absorbed dose rate, annual effective dose rate, ranged between 61.3932138.1076 nGyh−1 , 0.0830 - 0.211 mSvy−1 with mean values of 95.1762 ± 21.5257 and 0.1216±0.0359 respectively. The values obtained were compared with the reported data from UNSCEAR, 2000 and ICRP 2005. The excess lifetime cancer risk ranged between 0.00026-0.00061 with an average value of 8.44×10−4. The gamma, internal and external hazard indices ranged between 0.4631-1.0975, 0.5969- 0.9978 and 0.3601-0.8087 respectively. However, dose rates recorded in all locations were above the 60 nGyh−1 recommended limits by UNSCEAR 2000. Furthermore, Ganglare had a gamma index above 1, implying a significant radiation hazard. Also, the average excess lifetime cancer risk (ELCR) of 0.844 × 10−3 was relatively high (t &lt; 0.05) and compared to the world average value of 0.29 ×10−3. With the help of this study, we were able to establish the fundamental facts about the levels of radioactivity and related radiological dangers that exist in the soil of Mayo-Belwa Local Government.

Evaluation of natural radioactivity in soils of Konya (Turkey) and estimation of radiological health hazards.

Surface soil samples were collected from Konya, Turkey and natural activity concentrations were determined using the ɤ-ray spectroscopy system with HPGe detector. The activity concentrations of 226Ra, 232Th and 40K were found to vary from 14.07 ± 0.71 Bq kg-1 dw to 67.27 ± 1.62 Bq kg-1 dw, 10.19 ± 2.60 Bq kg-1 dw to 46.09 ± 0.76 Bq kg-1 dw and 107.87 ± 13.32 Bq kg-1 dw to 605.95 ± 11.34 Bq kg-1 dry weight (dw), respectively. The radiological hazard parameters such as Raeq, D, AEDE, ELCR, AGDE, Hex, Hin, and Iɤ evaluated the radiological risk for the public and environment. The mean values of D, AEDE and ELCR are lower than the world average value of 57 nGy h-1, 70 μSv y-1, 0.29 × 10-3 respectively. The activity concentration distribution maps of 226Ra, 232Th and 40K and the radiological maps of the radiological hazard parameters were plotted using the Surfer programme. Cluster analysis was carried out to indicate the similarity between the variables.

Determination of natural radioactivity using gamma spectrometry in used soils as construction materials in Qom province, Iran

The concentrations determination of natural radionuclides as radiation sources has an important role in reducing radiation risk and evaluating of non-nuclear activities impact. In this research, the concentrations of natural radionuclides 40K, 226Ra, and 232Th in the soil samples collected from 13 different locations in the Qom province (Delijan Cement Mine area) were measured by means of gamma-ray spectrometry using a shielded NaI (Tl) detector. For this purpose, the Nuclide master plus simulation program was used to evaluate the efficiency, and then the acquired data was validated. The activity concentrations of 40K, 226Ra, and 232Th varied within the ranges of 23.19 ± 1.95 to 287.19 ± 2.38, 3.04 ± 0.47 to 13.43 ± 0.56, 2.26 ± 0.37 to 4.63 ± 0.38 Bq.kg−1 with the mean values of 75.78, 8.69, and 3.30 Bq.kg−1, respectively. Radium equivalent activity, internal and external hazard indices were determined to assess radiological hazards. The mean Raeq was measured 19.26 Bq.kg−1 and Hex and Hin were calculated 0.052 and 0.075 which these quantities were lower than the world average. The results revealed that radiological risk due to natural radionuclides in this area was negligible and extracted soil samples as construction materials (cement) are safe.

Radiological hazard assessment for human from nuclear power plant effluent released under normal operation scenario (hypothetical case study)

This paper presents an assessment of the radiological hazard for humans from nuclear power plant effluent released into a river under normal operation scenarios (NOS). A hypothetical case study was conducted to estimate the annual effective dose (AED) received by the general public due to the discharge of effluent from the nuclear power plant. The results indicate that the radiological hazard for humans from nuclear power plant effluent released under (NOS) is minimal. The estimated AED received by the general public was found to be below 0.1 mSv/year, which is well below the annual dose limit of 1 mSv/y set by the International Commission on Radiological Protection (ICRP). The excess lifetime cancer risk (ELCR) detected remained within acceptable limits. These results estimated that nuclear power can be a safe and reliable source of energy when operated in accordance with established safety protocols. The study revealed that the concentration of 137Cs in sediments was higher than that of other radionuclides studied, leading to increased potential hazards over time. Overall, this study provides valuable information on the radiological hazard associated with nuclear power plant effluent released into a river under (NOS), which can be useful in the development of radiation protection strategies for nuclear power plants and in the communication of the risks associated with nuclear power to the public.

Behavior of 222Rn, 220Rn and their progenies along a daily cycle for different meteorological situations: Implications on atmospheric aerosol residence times and Rn daughters' equilibrium factors

The correct assessment of the radiological hazard from radon and daughters, external and internal doses, residence times and equilibrium factors, implies the need to properly determine 222Rn (radon), 220Rn (thoron) and their respective short-lived progenies (214Pb and 214Bi, and 212Pb and 212Bi, respectively), where the precise measurements of both progenies are quite complex due to their very short half-lives. In addition, it is important to study the temporal behavior of all these radionuclides along daily cycles. Therefore, the aim of this study was to analyze the temporal evolution of radon, thoron and their progenies, and of their activity ratios along daily cycles for two different meteorological situations (synoptic and mesoscale processes). Radon and thoron were measured using a radon monitoring system, while their respective progenies were collected onto atmospheric filters using an ASS-500 sampler, and then measured by gamma-ray spectrometry. Furthermore, the different relationships between the concentrations of radionuclides and the different meteorological variables of interest (temperature, ABL height, and speed and direction of the wind) were found. Finally, the atmospheric aerosol residence times and Rn daughters’ equilibrium factors were estimated for each sampling carried out along the two daily cycles, finding results consistent with previous studies.

Estimation of Background Radiation from A Soil Sample from A Barley Farm Area and Malt Factory in East Arsi, Ethiopia

The aim of this work is to estimate the background radiation of a soil sample from the barley farm area and Malt factory in East Arsi, Ethiopia. The technique of gamma-ray spectrometry with a high-purity germanium (HPGe) gamma-ray detector and a PC-based MCA was used. The activity concentration levels due to 40K, 137Cs, 238U, and 232Th were measured within the study area at a depth of 30 cm. The soils of the study region are used as construction material by many farmers. The measured specific activity of those radionuclides was compared with the data reported worldwide. The specific activity of radionuclides was estimated in both study locations. The specific activity 238U of soil samples ranged from 41.0 Bq kg-1 to 30.7 Bq kg-1 in the barley farm, with a mean value of 37.7 Bq kg-1, and for malt ranged from 23.8 Bq kg-1 to 40.6 Bq kg-1, with a mean value of 32.5 Bq kg-1. The specific activity of 232Th in soil samples ranged from 89.9 Bq kg-1 to 156.0 Bq kg-1, with a mean value of 118.6 Bq kg-1, whereas for the Malt factory ranged from 121.0 Bq kg-1 to 128.0 Bq kg-1, with a mean value of 123.7 Bq kg-1. In barley soil samples, the specific activity of 40K ranged from 401.0 Bq kg-1 to 530.0 Bq kg-1 with a mean value at the Malt plant ranged from 518 Bq kg-1 to 598.0 Bq kg-1, with a mean value of 553.6 Bq kg-1. Similarly, the specific activity of 137Cs was determined in both the barley farm and the malt Factory. In barley farm soil samples, it ranged from 3.3 ±0.6 Bq kg-1 to 5.34±0.6 Bq kg-1, and with a mean value of 4.3 Bq kg-1 whereas, in the Malt factory it varied from 3.1 ±0.7 Bq kg-1 to 5.3 ±0.7 Bq kg-1, and with a mean value of 4.5 Bq kg-1. The absorbed dose rate within the barley farm ranged from 24.6 ±2.9 nGyh-1 to 34.1 ±2.9 nGy h-1, and with a mean value of 30.6 nGyh-1, whereas, in the Malt factory, it varied from 31.3 ±1.3 nGy h-1 to 35.5 ±1.3 nGyh-1, and with a mean value of 33.5 nGy h-1. The annual effective radiation dose for BSS and MFSS was calculated to be 37.6 mSv y-1and 41.1mSv y-1. This study revealed that this region lies within a medium radiation background when compared with the world's average. The marginal value of dose is higher within the Malt factory area because of fertilizer consumption for cultivation. Since these estimated background and radiological impact factors are below the recommended values, it seems that there is no potential radiological health hazard related to the soils from both BSS and MFSS in Arsi Asella, Oromia, Ethiopia.

Assessment of Radiological Hazards in Drinking Water (Mineral Water) Consumed by the Malian Population Using Gamma Spectrometry

Assessment of Radiological Hazards in Drinking Water (Mineral Water) Consumed by the Malian Population Using Gamma Spectrometry

Assessment of radioactivity levels and radiation hazards in building materials in Egypt

Different degrees of natural radioactivity found in quartz can have negative consequences on health. Quartz vein along the investigated Abu Ramad area, Egypt, had its natural radioactivity assessed. The HPGe spectrometer was used to determine the role played by the radionuclides 238U, 232Th, and 40K in the gamma radiation that was emitted, and the results showed that these concentrations are 484.64 ± 288.4, 36.8 ± 13.1 and 772.2 ± 134.6 Bq kg−1 were higher than the corresponding reported global limits of 33, 45, and 412 Bq kg−1 for each radionuclide (238U, 232Th, and 40K). Among the radiological hazard parameters, the excess lifetime cancer risk (ELCR) is estimated and it's mean value of ELCR (1.2) is higher than the permissible limit of 0.00029. The relationship between the radionuclides and the associated radiological hazard characteristics was investigated based on multivariate statistical methods including Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). According to statistical research, the radioactive risk of quartz is primarily caused by the 238U, 232Thand 40K. Finally, applying quartz to building materials would pose a significant risk to the public.

Development of a novel low-pressure scintillation cell with ZnS(Ag)-coated clapboard for Rn-220 measurement

The high-precision measurement of Rn-220 is essential for assessing and preventing thoron radiological hazards. Prior research has revealed that employing a scintillation cell without a clapboard improves the detection efficiency for both Rn-222 and Rn-220 by reducing air pressure, and the Rn-220 calibration factor is established at an atmospheric pressure of 0.4. However, the decrease in air pressure leads to a corresponding reduction in Rn-220 concentrations within the scintillation cell, resulting in lower counts and larger statistical fluctuations. For the purpose of addressing this issue, a ZnS(Ag)-coated clapboard was added to the low-pressure scintillation cell for measuring Rn-222 and Rn-220. Several experiments were conducted in conjunction with Monte Carlo simulations. The results of these simulations, along with experiments using the standard radon chamber, provide valuable references for establishing the Rn-220 calibration factor. The experimental findings demonstrate that saturated detection efficiency of Rn-222 and Rn-220 can be maintained at below 0.7 atmospheric pressure. Therefore, the Rn-220 calibration factor, determined with the detection efficiency of 0.73 ± 0.04 at an atmospheric pressure of 0.7, was determined to be 31.98 ± 1.83 Bq·m−3·min−1 (k = 1).

Helical magnetic micromotors decorated with nickel ferrocyanide for the active and rapid adsorption of radiocesium in water

Separating radioactive cesium from nuclear waste and contaminated environments is critical to mitigate radiological hazards. In response to this need, remote-controllable and Cs-selective micromotor adsorbents have been considered as a promising technology for rapid in-situ cleanup while minimizing secondary waste and radiation exposure to workers. In this study, we demonstrate the active and rapid removal of a radioactive contaminant from water by leveraging the magnetic manipulation capabilities of a helical and magnetic Ni micromotor coated with Cs-selective nickel ferrocyanide (NiFC). The use of polyvinyl alcohol fibers as a template enables the straightforward preparation of the helical wire structure, allowing for precise control over the diameter and pitch of the helix through simple twisting with Ni wires. By harnessing Ni2+ ions eluted from the Ni micromotor in an acid solution, we successfully fabricate NiFC-coated Ni (NiFC/Ni) micromotors that exhibit a selective removal efficiency greater than 98% for 137Cs, even in the presence of high concentrations of competing Na+ ions. Under the influence of an external magnetic field, the NiFC/Ni micromotor demonstrates rapid motion, achieving a pulling motion (100 body lengths per second) through a magnetic gradient and a tumbling motion (46 body lengths per second) induced by a rotating magnetic field. The tumbling motion of the NiFC/Ni micromotor substantially improves the Cs adsorption rate, resulting in a rate that surpasses that achieved under nonmoving conditions by a factor of 21. This improved adsorption rate highlights the considerable potential of magnetically manipulated micromotor self-propulsion for efficient water-pollution treatment.

Assessment of radioactivity levels and radiological hazard indices in phosphate and phosphate mine waste samples from Algeria.

Phosphate ore is the starting raw material for production of all phosphate products including fertilisers phosphate waste. It can be of sedimentary, volcanic or biological origin. Like any other geological material found in nature, it contains various amounts of naturally occurring primordial radionuclides, such as 238U series, 232Th series and 40K. Gamma-ray spectrometry was used to assess natural radioactivity levels and radiological hazard indices in phosphate samples. In this paper, the specific activity concentrations of 226Ra, 232Th and 40K of phosphate ores, merchant and mine waste samples were determined. Based on the activity concentrations, the radiation hazard indices (Raeq, Hex, Hin and I𝛾𝑟), and the radiation doses (D, AED and ELCR) were calculated. The results were discussed and compared with those from other studies as well as recommended safety limit values.

Risk assessment and rare metals mineralization associated with alteration aspects of Rhyolite flow tuffs, Egypt

Argillic alteration and hematitization are the two extensive alterations that affected Um Safi rhyolite flow tuffs. Rare metal mineralization including radioactive minerals (thorite, uranothorite), Nb-bearing minerals (columbite, yettrocolumbite, Nb-rutile), zircon, REE-minerals (LREE-carbonate, xenotime) as well as molybdite, pyrite, fluorite, hematite and ilmenite have been identified by using Energy Dispersive Spectrometer (EDS) and are well recorded in argillic and hematitized samples. The investigated rhyolite flow tuffs show that the activity concentration of radionuclides changed from 1.2 to 453.2 Bq kg−1 for 238U, from 3.2 to 489.6 Bq kg−1 for 232Th, and from 31.3 to 88954.6 Bq kg−1 for 40K. The mean values of 238U, 232Th, and 40K activity concentrations are 90.8 ± 84.5, 122.9 ± 90.5 and 6286.7 ± 1562.2 Bq kg−1, respectively. The hazard factors are estimated. Their results exceeded the recommended limit. Thus, the investigated rhyolite flow tuffs are not safe to use in building materials and other construction industries. A multi-statistical approach is performed to show the correlation between the radioactive concentration and radiological hazard factors. This approach illustrates the positive correlation between uranium and thorium due to their contribution from the natural radioactive series—moreover, a strong correlation was obtained between potassium and all radiological parameters. Thus, the radioactive hazards impact in the present study is related to the presence of radioactive minerals such as thorite and uranothorite in addition to other accessory minerals.

Quantification of radiological hazards associated with natural radionuclides in soil, granite and charnockite rocks at selected fields in Ekiti State, Nigeria

Assessment of activity levels of radionuclides that exist in soil, granite, and charnockite rock samples is very crucial because it exhibits an enhanced elemental concentration of uranium (U) and thorium (Th) contributing higher natural background activity than usual in the environment and it may cause health risk to human health through the external and internal exposure. This study determined the radioactivity levels of 238U, 232Th, and 40K radionuclides in soil, granite, and charnockite rock samples collected from selected fields in Ekiti State, Nigeria using Caesium iodide CsI(Tl) scintillation gamma spectrometer. It also evaluated indices of the radiological parameters consisting of radium equivalent activity (Raeq), absorbed dose rate (DR), annual effective dose equivalent (AEDE), internal hazard index (Hin), and excess lifetime cancer risk (ELCR). The calculated average activity concentrations of 238U, 232Th, and 40K are 30.40 ± 0.71 Bq kg−1, 3.31 ± 0.05 Bq kg−1, and 222.25 ± 14.72 Bq kg−1, respectively, which were lower than their respective world average values. Comparatively, potassium concentrations in these collected samples have a higher value than concentrations of uranium and thorium (40K > 238U > 232Th). All the evaluated values of the radiological parameters (except DR) of the appraised radionuclides were below the global permissible limits. The granite rocks, charnockite rocks, and soils from Ekiti State in Nigeria do not pose any hazardous risk to humans, but continued monitoring is necessary when these materials are used as building materials, which cause long-term radiation exposure.

Assessment of natural and anthropogenic radioactivity levels and their radiological hazards in surface soil samples around oil refinery, Little Aden City, Yemen

The activity concentration of global fallout of 137Cs and naturally- occurring radioactive materials (NORM), which primarily due to the geological and geographical condition of soil. and maybe occur from oil and gas burring processes and consequently accumulate on surface soil around the oil refinery in Aden Assoghra city, Yemen were studied by use the gamma-ray spectrometer equipped with a high purity germanium (HPGe) detector and specially designed shield. The average concentrations of 226Ra, 232Th, and 40K expressed in (Bq kg−1) of the studied samples were (13 ± 0.44) Bq kg−1, (22.1 ± 0.64) Bq kg−1 and (509 ± 9) Bq kg−1, respectively. Low concentrations of 137Cs were noted from some sample in the study area, where ranged from (0.3 ± 0.2) to (1.7 ± 0.2) Bq kg-1. The average values of calculated radiological hazard indices were 40.6 nGy h−1 (absorbed dose rate outdoors), 0.05 mSv y−1 (annual effective dose outdoors), 0.279 mSv y−1 (annual effective dose indoors), 83.7 Bq kg−1 (radium equivalent), 0.23 (external hazard index), 0.26 (internal hazard index), 0.65 (representative level index), 0.174×10-3 (the excess lifetime cancer risk ELCR) and 0.292mSv y−1 (annual gonadal equivalent dose, AGED).

Radiological risk assessment of beaches from volcanic oceanic islands: A case study of the Eastern Canary Islands (Spain)

This work constitutes the first survey that allows the establishment of baseline levels of environmental radioactivity in beach sands from the volcanic oceanic islands of La Graciosa, Lanzarote, Fuerteventura and Gran Canaria. Activity concentration values of 226Ra, 232Th and 40K were measured by gamma spectroscopy in 108 samples, collected from 39 beaches across the whole study region. The radiological hazard risks associated with these sands were studied. The mean absorbed dose rate in the study region was 20 nGy h−1, which is below the world average value. The mean outdoor annual effective dose for the beaches studied was 0.025 mSv y−1, which is within the internationally accepted safe limit. Additionally, the assessment of the radium equivalent showed that all samples from the Eastern Canary Islands are below the safe limit of 370 Bq kg−1. Despite not posing any radiological risk to the human population, the radiological hazard indices obtained in Gran Canaria were significantly higher than those of other islands. These significant differences seem to be related to the presence of sediments in the beaches of Gran Canaria that have their origin in lithologies with higher activity concentration values of 226Ra, 232Th and 40K that are not present in the rest of the islands.

Analysis of the radiological dose and hazards assessment around swampy agricultural soil in Keffi, Nasarawa State, Nigeria

The present study analyzes radiological dose and hazard around the swampy agricultural soil in Keffi Local Government Area of Nasarawa State, using determined activity concentration (AC) of 238U, 232Th and 40K obtained from swampy agricultural soil samples, systematically collected from Ten (10) sampled points. Samples collected were further analyzed using a sodium iodide detector for activity concentrations of 238U, 232Th and 40K. The average AC of 238U, 232Th and 40K were 26.73±4.64, 9.77±2.57 and 1115.52 ±67.43 Bq/kg, respectively. The gamma absorbed dose rate (Dabs) ranges from 6.37E-01 to 2.33E+01 nGy/hr with a mean value of 6.10E+00 nGy/hr. The annual effective dose equivalent (AEDE) ranges from 8.12E-03 to 2.97E-01 mSv/yr with an estimated mean value of 7.77E-02 mSv/yr. The annual gonadal dose equivalent ranges from 4.48E-02 to 1.72E+01 mSv/yr with a mean value of 4.49E-01 mSv/yr. The calculated radium equivalent activity ranges from 1.44E+01 to 4.49E+02 Bq/kg with a mean value of 1.18E+02 Bq/kg, which falls below the recommended standard value of 3.7E+02 Bq/kg. The external and internal hazard index ranges from 3.89E-02 to 1.21E+00 mSv/yr with a mean value of 3.20E-01 mSv/yr, and 3.90E-02 to 1.41E+00 mSv/yr with a mean value of 3.70E-01 mSv/yr. The gamma hazard index ranges from 5.24E-02 to 1.84E+00 mSv/yr with a mean value of 4.83E-01 mSv/yr. The activity utilization index ranges from 8.65E-02 to 1.34E+00 mSv/yr with a mean value of 3.82E-01 mSv/yr, excess life cancer risk (ELCR) for both adult and child was found to be 1.94E-01 and 2.72E-01, respectively, higher than the recommended world average value of 0.29E-03. The high value of ELCR implies that residents around the study area have a high chance of developing cancer over a lifetime. Hence periodic radiological dose and hazard analysis is recommended to keep the exposure as low as reasonably achievable.