Naturally Occurring Radioactive Materials Research Articles

Regulatory requirements to support a specific regulation of oil norm waste in Brazil.

The oil and natural gas industry is one of the largest producers of Naturally Occurring Radioactive Material (NORM) worldwide. The scale and sludge are NORM wastes with the highest activity concentration levels, reaching 3500Bq per g of 226Ra (scale). As wastes (sludge, scale, and produced water) are constantly produced in routine activities, a specific regulation for these wastes is necessary. Therefore, this study presents the regulatory requirements that may serve as a basis for the responsible regulatory body to prepare a specific regulation for the NORM waste generated by the oil industry. As a study published showing that the disposal of bulk NORM waste (not packaged wastes) is viable in Brazil, requirements for the management of these wastes and the characteristics of the landfill for disposal were included.

A review of radiation doses and associated parameters in Western Australian mining operations (2020-23)

Government policies have stimulated the Western Australian (WA) mining industry to position itself as a significant global supplier of critical minerals, including lithium and rare earths. In WA the lithology that supports these minerals is often associated with elevated concentrations of naturally occurring radioactive materials (NORMs) and the increase in the number of mining operations pursuing the minerals has witnessed a commensurate increase in the number of workers potentially exposed to the radiation emitted from the NORMs. The regulatory framework for radiation protection in WA mining operations underwent significant change with the implementation of the Work Health and Safety Act 2020 and Work Health and Safety (Mines) Regulations 2022 which both came into effect on the 31 of March 2022. Under the new framework mining operations identified as having workers who were likely to receive annual effective doses (EDs) from NORMS above one mSvy-1are referenced asrelevant mines (RM). RMs are required to submit an annual report of the estimates of EDs)received by their workforce to the mining regulatory authority (WorkSafe WA: Mines Safety). This research provides an overview of the new legislative framework and updates the information in Ralph and Cattani (2022J. Radiol. Prot.42012501) to include data derived from annual occupational EDs submitted by RMs in the three-year period spanning 2020-21, 2021-22 and 2022-23. In 2022-23, 38 mining operations were identified as RMs, an increase of ten from 2021-22 which in turn had increased by six from the 2020-21 reporting period. The mean annual ED reported for the three-year period was 1.0 mSv, the level at which regulatory intervention should be considered. The maximum ED was 4.9 mSv, just below the threshold of 5 mSv above which exposed workers are considered Designated Workers and are subject to focused monitoring. The collective effective annual dose of the mine worker population reached an historical maximum of 2339 man mSv in 2022-23. Analysis of the three main exposure pathways confirms that inhalation of long-lived alpha emitting radionuclides in dust remains the most significant contributor to worker EDs. Inhalation of radon-222 and radon-220 and their short-lived progeny, once considered as a negligible contributor to worker annual EDs is the second most significant exposure pathway. A declining trend in the number of samples collected per worker is highlighted as requiring remediation to provide confidence in the reported annual EDs. The transition to the new legislative framework for radiation protection in mines has been supported by the publication of guidance materials which have been widely endorsed by the industry.

Analysis of Naturally Occurring Radioactive Material (NORM) in shifting earth layers in Piyungan, Bantul

In recent decades, understanding the correlation between radon gas emissions and geodynamic processes has been pivotal in enhancing geophysical monitoring. This study advances current methodologies by refining radon data analysis and employing mathematical models to further elucidate this relationship. We developed a radon well geometry for Piyungan using Finite Element Method principles, and conducted simulations via GNU Octave to assess normal and anomalous conditions. The results indicate a basal radon concentration of 2.2420 Bq/L at a depth of 14.2308 m. Notably, radon levels inversely correlate with the water volume and diffusivity, yet proportionally increase with soil moisture. These findings offer a nuanced understanding of radon behavior in response to geodynamic activity, paving the way for improved environmental monitoring.

Mode-driven explainable artificial intelligence approach for estimating background radiation spectrum in a measurement applicable to nuclear security

This study introduces an explainable artificial intelligence (XAI) approach designed to estimate background spectra in unknown spectral measurements. The approach combines kernel-modeled Gaussian processes (GP) for naturally occurring radioactive material (NORM) estimation with fuzzy logic inference for isotopic photopeak identification. Recognizing the diverse interpretations of background radiation, the paper’s objective is to propose a multi-mode driven approach, with each mode implementing a distinct set of fuzzy rules, thus modeling different backgrounds. Importantly, each mode includes rules associated with nuclides expected to be present in specific locations, such as medical isotopes in a hospital setting. A key innovation of the method is the additional step of providing explanations for the estimated contributions that accompany the estimated background spectrum. Results obtained from a range of gamma-ray spectra representing different locations demonstrate the framework’s potential in estimating background radiation and aiding decisions in the nuclear security domain, particularly for identifying potential nuclear threats in unknown measurements.

Environmental Radiological Impact and Risk Assessment of Natural Radioactivity at the Heap Leach Facility of Tarkwa Goldmine, Ghana: Radiotoxicity and Public Exposure

In this study, a comprehensive investigation was conducted to determine the radioactivity levels of naturally occurring radioactive materials (NORMs) in heap pads/soil and water samples within and around the operational area of Tarkwa Gold Mine in Ghana. Gamma-ray spectrometry was used to determine the activity concentrations of 238U, 232Th, and 40K in heap pads/soil, and 226Ra, 228Th, and 40K in water samples. The average activity concentrations of 226Ra and 228Th in all water samples were below the World Health Organisation (WHO) recommended guidelines for drinking water. Similarly, the average activity concentrations of measured radionuclides in heap pads/soil samples taken from depths of 0–20 cm and 20–50 cm were found to be below the worldwide average reported values. The annual effective dose to the public was estimated to be around 0.16 mSv, which is below the recommended limit. The values of the hazard indices are also below the recommended limits, implying that if heap pads/soils are used for building purposes and construction, they will not pose any significant radiation hazard. The results of this study indicate that radiation levels are within the natural background radiation levels reported in the literature and are consistent with findings from similar studies conducted in Ghana.

Uranium mining effluents: What about the re-use of mining wastes to improve the bioproduction of industrially relevant bioactive compounds?

The shift towards a circular economy, where waste generation is minimized through waste re-use and the development of valorization strategies, is crucial for the establishment of a low carbon, sustainable, and resource-efficient economy. However, there is a lack of strategies for re-using and valorizing specific types of waste, particularly those containing naturally occurring radioactive materials (NORM), despite the prevalence of industrial activities that produce such waste due to their chemical and radiological hazards.Living organisms, including fungi, are valuable sources of bioactive compounds with various industrial applications. In this study, we assessed the growth and metabolic profile changes of three white rot fungi species in response to low concentrations of a uranium mine effluent containing NORM and metals to explore their potential for producing biotechnologically relevant bioactive compounds. The growth rate was assessed in three different culture media, with and without the uranium mine effluent (1% V/V)), and the metabolic profile was analyzed using FTIR-ATR spectroscopy.Results suggested an improvement in growth rates in media containing the uranium mine effluent, although not statistically significant. T. versicolor showed promise in terms of bioactive compound production. The production of droplets during growth experiments and significant metabolic changes, associated with the production of bioactive compounds like laccase, melanin, and oxalic acid, were observed in T. versicolor grown in mYEPDA with the uranium mine effluent. These findings present new research opportunities for utilizing waste to enhance the biotechnological production of industrially relevant bioactive compounds and promote the development of circular economy strategies for re-using and valorizing NORM-containing waste.

Hematological and neurological impact studies on the exposure to naturally occurring radioactive materials

Naturally Occurring Radioactive Materials (NORM) contribute to everyone's natural background radiation dose. The technologically advanced activities of the gas and oil sectors produce considerable amounts of radioactive materials as industrial by-products or waste products. The goal of the current study is to estimate the danger of long-term liability to Technologically Enhanced Naturally Occurring Radioactive Materials (TE-NORM) on blood indices, neurotransmitters, oxidative stress markers, and β-amyloid in the cerebral cortex of rats' brains. Twenty adult male albino rats were divided into two equal groups (n = 10): control and irradiated. Irradiated rats were exposed to a total dose of 0.016 Gy of TE-NORM as a whole-body chronic exposure over a period of two months. It should be ''The results showed no significant changes in RBC count, Hb concentration, hematocrit percentage (HCT%), and Mean Corpuscular Hemoglobin Concentration (MCHC). However, there was a significant increase in the Mean Corpuscular Volume of RBCs (MCV) and a significant decrease in cell distribution width (RDW%) compared to the control. Alteration in neurotransmitters is noticeable by a significant increase in glutamic acid and significant decreases in serotonin and dopamine. Increased lipid peroxidation, decreased glutathione content, superoxide dismutase, catalase, and glutathione peroxidase activities indicating oxidative stress were accompanied by increased β-amyloid in the cerebral cortex of rats' brains. The findings of the present study showed that chronic radiation liability has some harmful effects, that may predict the risks of future health problems in occupational radiation exposure in the oil industries. Therefore, the control of exposure and application of sample dosimetry is recommended for health and safety.

Assessment of Natural Occurring Radioactive Materials and Radiological Hazards Exposure in Soil of Ohia in Umuahia South Abia State Nigeria, Using High Purity Germanium (HPGe) Gamma Ray Spectrometry

Evaluation of natural occurring radioactive materials (NORMs) and radiological exposure are important. The main goal of this work was to determine the NORMs level and radiological exposure risk in Umuahia, using High Purity Germanium Gamma Ray Spectrometry at IPEN, Brazil. The radionuclides (RDNs) such as: 40K, 226Ra and 232Th and radiological parametric indices (RPIs) such as: Absorbed Dose Rate in Air (D), Outdoor and Indoor Annual Effective Dose Equivalent (AEDE), Radium Equivalent Activity (Raeq), Annual Gonadal Equivalent Dose (AGED) and Activity Concentration Index (I) were determined. The mean values of 40K, 226Ra and 232Th in Bq kg-1 were: 147, 28, and 31 while the RPIs mean values for D, ,, AGED, Raeq, and I are: 37 nGy h-1, 0.05 mSv y-1, 0.18 mSv y-1, 260 y-1, 83 Bq kg-1 and 0.29 respectively. Mean value of RDNs were found to be lower than 412 Bq kg-1, 32 Bq kg-1 and 35 Bq kg-1 average value while RPIs were also lower than 59 nGy h-1, 0.08 mSv y-1 for , 0.42 mSv y-1, 300 y-1 for AGED, 370 Bq kg-1 for Raeq, and 1 mSv y-1 respectively global safe limit or mean values. It is concluded that the soil is radiological safe for agriculture, building and construction purposes.

Assessment of Natural Occurring Radioactive Materials and Radiological Hazards Exposure in Soil of Ohia in Umuahia South Abia State Nigeria, Using High Purity Germanium (HPGe) Gamma Ray Spectrometry

Evaluation of natural occurring radioactive materials (NORMs) and radiological exposure are important. The main goal of this work was to determine the NORMs level and radiological exposure risk in Umuahia, using High Purity Germanium Gamma Ray Spectrometry at IPEN, Brazil. The radionuclides (RDNs) such as: 40K, 226Ra and 232Th and radiological parametric indices (RPIs) such as: Absorbed Dose Rate in Air (D), Outdoor and Indoor Annual Effective Dose Equivalent (AEDE), Radium Equivalent Activity (Raeq), Annual Gonadal Equivalent Dose (AGED) and Activity Concentration Index (I) were determined. The mean values of 40K, 226Ra and 232Th in Bq kg-1 were: 147, 28, and 31 while the RPIs mean values for D, ,, AGED, Raeq, and I are: 37 nGy h-1, 0.05 mSv y-1, 0.18 mSv y-1, 260 y-1, 83 Bq kg-1 and 0.29 respectively. Mean value of RDNs were found to be lower than 412 Bq kg-1, 32 Bq kg-1 and 35 Bq kg-1 average value while RPIs were also lower than 59 nGy h-1, 0.08 mSv y-1 for , 0.42 mSv y-1, 300 y-1 for AGED, 370 Bq kg-1 for Raeq, and 1 mSv y-1 respectively global safe limit or mean values. It is concluded that the soil is radiological safe for agriculture, building and construction purposes.

Radiation protection for Gabes phosphate area residents: Assessing natural radioactivity in soil and potable water samples

Phosphate mining activities are recognized to be one of various industrial processes generating enhanced Naturally Occurring Radioactive Materials (NORM) by introducing natural radionuclides into the surrounding soils and water bodies, posing a risk to human health.This study was carried out to assess the level of natural radionuclides in soils and potable waters collected from the phosphate area of Gabes city, located in southeastern Tunisia, and to evaluate radiation protection measures by estimating radiological health hazard parameters. Gamma spectrometry system employing an HPGe detector was used in this study to assess 40K, 232Th and 226Ra activity concentration in soils. The average values were found to be 163.7, 14.5, and 7.7 Bq kg−1, respectively, which were lower than worldwide average values. The radiological hazard parameters assessed in this study were radium equivalent activity (Ra-eq), external hazard index (Hex), external gamma absorbed rate (GDR), external annual effective dose (Deff) and excess lifetime cancer risk (ELCR). The calculated average values of the above-mentioned parameters were of 41 Bq kg−1, 0.1, 20.2 nGy h−1, 24.8 μSv y−1 and 8.7 × 10−5 all of which were found to be below their permissible standards.For potable water samples, the activity concentrations of radium were analyzed using an HPGe detector and those of uranium were determined by alpha spectrometry. The average activity concentrations of uranium and radium isotopes in underground water samples were found to be higher than those obtained in tap water samples. For both types of water, the average values for all radionuclides were found to be below their respective reference limits.The annual ingestion effective doses were also estimated in this study. The estimated average values for infant and children for underground water samples were higher than the permissible limit of 100 μSv y−1 set by WHO. The 226Ra was the main contributor to the effective doses for different age categories, followed by 228Ra.

Construction and validation of parametric models to predict radium sorption in soils

Elucidating the factors affecting the transfer of naturally occurring radionuclides (NOR) between environmental compartments is a key part of the assessment of ecosystem's exposure to naturally occurring radionuclide materials (NORM). For that, the sorption and desorption solid-liquid distribution coefficients (Kd) of radium (Ra) were quantified in a collection of 31 soil samples with contrasting edaphic properties under controlled conditions in laboratory batch experiments. Ra sorption was demonstrated to be moderate to high, with Kd (Ra) values ranging from 102 to 103 L kg−1. Ra sorbed was mostly irreversible, as evidenced by desorption percentages lower than 2 %. An exploratory analysis with partial least squares (PLS) regression identified the soil properties that correlated with Kd (Ra) and discarded those that were not relevant for describing Kd variability. A dataset of the sorption Kd (Ra) values and associated soil properties was built from our own data and from the literature after performing an in-depth review of similar Ra sorption studies. For the first time, Kd (Ra) parametric prediction models were constructed using univariate linear regression (ULR) and multivariate linear regression (MLR). Ra sorption in soils was mostly explained by the soil properties directly or indirectly related to the available exchange sites, such as the levels of water-soluble and exchangeable Ca and Mg as well as the pH of the contact solution. The most promising models explained around 80 % of the Kd (Ra) data variance, only needing Kd (Ca + Mg) or additional soil descriptors such as pH, Mn content, and the specific surface area. The validation of the proposed models confirmed that Kd (Ra) can be predicted with only a few soil properties that can be characterised in routine analysis. Thus, the proposed models could be used to estimate the interaction of Ra in soils in risk assessment.

Measurement of Naturally-Occurring Radioactive Materials (NORM) using a scintillator-based alpha detector

It is important to differentiate between natural and artificial radioactive materials such as plutonium in nuclear facilities. In this study, a scintillator-based alpha-particle detector was developed using YAP:Ce scintillator and Multi-Anode PhotoMultiplier Tube. The detector was used to measure various naturally occurring radioactive materials (NORM) samples including radon progeny, lead plate, lantern mantle, and radium ceramic ball. The measurement results were compared with Monte Carlo simulation calculations and were found to be in agreement. The energy resolution of the detector is 8.6%FWHM. In the measurement results of radon progeny, peaks of 212Bi (6.1 MeV), 214Po (7.7 MeV), and 212Po (8.8 MeV) can be observed. The lead plate contains 210Po and emits 5.3 MeV alpha particle. The simulation with the same energy was able to reproduce the actual measurement. The results showed the energy and distribution of the alpha particles emitted by the NORM samples. The study successfully demonstrated the capability of the developed alpha-particle detector in identifying NORM.

Naturally occurring radioactive material (NORM) in Saudi Arabia: A Review

Saudi Arabia, the world's largest crude oil exporter, also possesses rich deposits of natural resources like phosphate, bauxite, copper, and various minerals. Extracting and processing these resources can concentrate naturally occurring radionuclides in the resulting products, byproducts, residues, and wastes. This can sometimes elevate their activity concentrations above original levels, potentially increasing exposure risks for workers and the public, and contaminating the environment.This review provided a comprehensive overview of naturally occurring radioactive materials (NORM) across various industries in Saudi Arabia. It outlines the regulatory framework established by the country's authority for NORM management. By reviewing current literature, the article presents activity concentrations of key radionuclides of interest - 40K and those from the 238U and 232Th decay series-within different industries. The review highlights the need for further research to assess the impact of industrial processes on the activity concentrations of natural radionuclides. It concludes by calling for additional studies to address the significant knowledge gap on NORM in specific industries, particularly phosphate, bauxite, water treatment plant and oil and gas, which have the potential to generate radioactive waste. The importance of characterizing industries involving NORM is emphasized for evaluating radiological impact and implementing appropriate safety measures.

Response of Microbial Communities to Naturally Occurring Radioactive Material-Contaminated Sediments: A Microcosm-Based Study.

There is a growing need to understand the potential ecological impacts of contaminants in offshore oil and gas infrastructure, especially if that infrastructure is to be left in situ as a decommissioning option. Naturally occurring radioactive material (NORM) is one type of contaminant found in solid deposits on internal surfaces of infrastructure that poses potential ecological harm if released into the marine environment. Microbes are important components of marine sediment ecosystems because they provide ecosystem services, yet the impacts of NORM contamination to these communities are not well understood. The present study aimed to investigate the response of benthic microbial communities to NORM-contaminated scale, collected from an offshore oil and gas system, via controlled laboratory microcosm studies. Changes to microbial communities in natural sediment and sediments spiked with NORM at radium-226 activity concentrations ranging from 9.5 to 59.8 Bq/kg (in partial equilibria with progeny) over 7 and 28 days were investigated using high-throughput sequencing of environmental DNA extracted from experimental sediments. There were no significant differences in microbial community composition between control and scale-spiked sediments over 7 and 28 days. However, we observed a greater presence of Firmicutes in the scale-mixed treatment and Chloroflexi in the scale-surface treatments after 28 days. This could suggest selection for species with contaminant tolerance or potential resilience to radiation and metal toxicity. Further research is needed to explore microbial tolerance mechanisms and their potential as indicators of effects of radionuclide-contaminated sediments. The present study demonstrated that microcosm studies can provide valuable insights about the potential impacts of contamination from oil and gas infrastructure to sediment microbial communities. Environ Toxicol Chem 2024;43:1648-1661. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Spatial distribution of NORMs concentrations and assessing potential risk to inhabitants in western Chattogram, Bangladesh

ABSTRACT This study represents a pioneering endeavour in consolidating previous measurements of naturally occurring radioactive materials (NORMs) within the Chattogram division, Bangladesh. Employing a meticulous approach, data was overlaid onto a comprehensive grid map covering the entire Chattogram region, comprising 523 grids, each of 8.05 km x 8.05 km. The analysis revealed numerous areas where NORMs concentrations had not been previously measured. To bridge this gap, soil samples were collected from 56 previously unmeasured locations across Cumilla and Chandpur districts and analysed using high purity Germanium (HPGe) detector technology. Results indicated average activity concentrations of Ra-226, Th-232, and K-40 at 27.30 ± 5.41, 46.09 ± 7.88, and 362.50 ± 48.10 Bq.kg−1 respectively, with no detectable presence of Cs-137 or other anthropogenic radionuclides, affirming the region’s absence of fallout or accidental releases. Additionally, measured values for radiation hazard indices are well within acceptable limits set by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Spatial distribution maps of radionuclide concentrations and absorbed dose rates were generated not only for the immediate study area but also for the entire Chattogram division, integrating previously collected data for the first time. These distribution maps, alongside the comprehensive findings of this study, establish a pivotal dataset for future research and regulatory efforts, providing invaluable insights into the region’s radiological landscape.

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

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

Assessment of Radiation Dose Associated with Background Radionuclides in Quarry Soil at Dawakin-Kudu LGA Kano, Nigeria

Naturally occurring radioactive materials (NORMs) are present in different concentrations in the environment as well as quarry depending on the geological formation of the soil. The assessment of any release of radioactivity into the environment is crucial for safeguarding public health, particularly when this radioactivity has the potential to enter the food chain. The quarry located in Dawakin-Kudu Kano has the potential to exhibit elevated levels of natural radioactivity due to intense mining operations. This study presents the assessment of activity concentration in quarry soil at Dawakin-Kudu with a focus on the transfer mechanism from soil to plant. Soil samples were gathered from a quarry site and farmlands situated around the quarry at Dawakin-kudu, plant samples were also collected from the same farmlands and were all analyzed for natural radioactivity, specifically for 226Ra,232Th, and 40K. The gamma-ray spectrometry method, coupled with the Sodium thallium Iodide NaI (Tl) detector was used to measure the activity concentrations of 226Ra,232Th, and 40K. Activity concentrations of natural radioactivity in soil were generally higher than those recorded in plants. The mean activity concentration of the radionuclides in soil ranges from Highest-to-Lowest values as follows 226Ra: 65.24±1.92 Bqkg-1 – 42.41±1.73 Bqkg-1, 232Th: 182.71±1.44 Bqkg-1 – 114.61±1.25 Bqkg-1, 40K: 597.51±3.81 Bqkg-1 – 321.93±3.55 Bqkg-1. The radiological hazard indices were all determined to assess the radiation hazard of the quarry soil. The radionuclides transfer factor showed a higher value for 40K in the order 40K>232Th >226Ra, this implies high bioconcentration of 40K in plants. The findings suggest that consuming plants grown around the quarry location over an extended period could pose substantial health threats to the public. Consequently, the study area may not be safe for residents in the long run, emphasizing the necessity for continuous monitoring of radioactivity concentrations to mitigate the environmental health implications of accumulated...

Assessment of the radionuclide remediation potential of novel miscanthus hybrids

There are few studies related to the radionuclide remediation options, which comply to the demands of the environmentally non-destructive physical remediation methods. So far, most of the research was conducted on the phytoremediation capacity of different energy crops, as well as the established miscanthus hybrids which involved metal and heavy metal contaminants. Hence, the objective of this research was the radioecological characterization of the examined agroecosystem, including the initial source of the radionuclides (soil) as well as different miscanthus hybrids grown on the same soil. The results have shown that the radioactive content of soil was similar to the global averages. All measurements of the activity concentration of 137Cs in miscanthus samples were below the detection limits. There is also an indication that 210Pb is leaching into the lower layers (or is being taken up by miscanthus plant from the upper layers). Moreover, transfer factors (TFs) for radionuclides, as a more precise parameter for evaluating the phytoremediation potential, were calculated; the TFs were found to be very low for 226Ra (≤0.07), TFs for 40K (≤0.39) and for 232Th (≤0.21) were in the lower limits, whereas the TFs for 238U were found to be the highest (≤0.92). For 210Pb, the TFs were not calculated, since the expectation was that a significant part of the measured quantity came from the air, and not through the soil. Having in mind the sustainability and the circularity aspect of the radionuclide phytoremediation system, the appropriate management method should be applied for the disposal and utilization of the biomass contaminated with radionuclides. This research has shown that the radiological content in miscanthus is high enough and the ash content is low enough that miscanthus ash could be considered as a NORM (Naturally Occurring Radioactive Material), and it can be further used for the construction industry (i.e. concrete, tiles), in mixtures with other materials with certain limitations, similar to the utilization of ash from other sources such as coal or wood.

Assessment of occupational external radiation exposure of workers in the Southwest of Libya using portable NaI detector

In this study, gamma dose rates generated from the naturally occurring radioactive materials (NORM) were measured in the waste streams of a large scale and sludge onshore petroleum operations. Measurements conducted in this work involved: sludge recovery from separation tanks, sludge forming, NORM storage, scaling in oil tubulars, scaling in gas production and sedimentation in produced water evaporation ponds. Field work was carried out in many places of different terrain of an operation oil exploration and production in Murzuq basin in the Southwest of Libya. The radiation dose rates were measured using portable InSpector-1000. A total of 400 dose rates were acquired. The highest dose rate was 70 μSv/h acquired in sludge stored in barrels. The estimated mean annual equivalent doses in this field were in the range of 0.2–2.8 mSv/y in the first scenario, while in the second scenario the calculated mean annual equivalent doses were in the range of 0.04–0.68 mSv/y. It is assumed that workers may face various exposures in the field where measurements took place, considering the total annual effective dose to be 1.53 mSv/y. The main radioisotopes detected in these samples indicated by the display of the measuring device were 226Ra and 228Ra but detecting both radioisotopes in the same run is not achievable by using the display of the screen.

Assessment of radioactivity level and associated radiological hazard in riverbed samples within industrial areas

ABSTRACT Terrestrial gamma radiation is one of the major outdoor radiation exposures to the general public that varies substantially based on the type and geological properties of the soil. The objective of this study is to evaluate the naturally occurring radioactive materials (NORMs) distribution and assess the hazard parameters in the riverbank soil within various industrial zones in the densely populated Dhaka and Chattogram cities of Bangladesh. The mean activities of 226Ra (37 ± 3), 232Th (58 ± 4), and 40K (1129 ± 18) Bqkg−1 in the assessed soil samples were found to be slightly higher than the world average values 32, 35, and 420 Bqkg−1, respectively. The mean radium equivalent activity (207.49 Bqkg−1) and the external and internal hazard indices were within the recommended limits of 370 Bqkg−1 and <1, respectively. The mean absorbed dose rate (99.47 nGyhr−1), annual effective dose (0.12 mSva−1), ELCR (4.27 × 10−4), and gamma level index (1.58) exceeded the world average values 59 nGyhr−1, 0.07 mSva−1, 2.9 × 10−4, and 1 respectively. However, the studied areas are safe from a radiological viewpoint with no radiation health hazard to the people. The results of this study can be utilized to produce factual baseline data for future studies.