Naturally Occurring Radioactive Materials Research Articles

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.

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.

Radiological Risk Assessment of Soil Using RESRAD-OFFSITE Code in Communities around Indorama Fertilizer Company Eleme, Port-Harcourt, Rivers State, Nigeria

Anthropogenic activities around a fertilizer company can cause elevation in the concentration of naturally-occurring radioactive materials (NORMs) within surrounding soils, as a result of effluent discharge or heaping of rocks used as raw materials. The aim of this study was to evaluate the human risk associated with exposure to NORMs in soils from communities around Indorama Fertilizer Company Eleme, Port-Harcourt, Rivers State, Nigeria. A sodium-iodide doped with thallium [NaI(TI)] detector was used to measure activity concentrations of these NORMs in 22 soil samples within the study area. The residual radioactivity (RESRAD) offsite modeling program(version 4.0) was then used to estimate the radiation doses and the cancer morbidity risk of uranium-238 (238U), thorium-232 (232Th) and potassium-40 (40K) for hypothetical resident farmer scenario. According to the RESRAD prediction, the maximum total effective dose equivalent (TEDE) during 100 years was found to be 2.82 x 10-5 mSvy-1 at year 12, while the maximum total excess cancer morbidity risk for all the pathways was 3.52E-08 at year 6. Therefore, results obtained from the RESRAD-OFFSITE code in this study has shown that the health risk from effluent discharge within the study area is within acceptable levels according to international standards.

Assessment of NORMs (238U, 232Th, 40K) and radiation hazard indices in Beldih apatite mine region of Purulia district, West Bengal, India.

The radiation arising from naturally occurring radioactive materials (NORMs) is the foremost contributor to the collective dose received by the global population. The present study aims to measure the natural background radiation level and the associated gamma radiation dose in air in the Beldih apatite mine region of Purulia district, India. This study is primarily focused on the determination of 238U, 232Th and 40K activities in the sub-surface soil of the study area. The measurements were carried out using a High Purity Germanium (HPGe) detector-based gamma-ray spectrometer with a relative efficiency of 80%. To achieve uniformity in exposure estimations, radium equivalent activity has been calculated. Additionally, the internal hazard index, external hazard index, radioactivity level index and gamma dose rates have been evaluated to estimate the radiation hazard levels in the study area. The comparison of obtained concentrations and hazard indices with global data (UNSCEAR. (2008). Sources, effects and risks of ionizing radiation. United nations scientific committee on the effects of atomic radiation (report to the general assembly, with Annexes).) suggests that this region lies in a relatively high background radiation zone.

Assessment of Be-7, Pb-210 and Po-210 Activities in Airborne Particulate Matter Over Istanbul, Türkiye.

Airborne particulate matter is one of the air pollutants which can have detrimental health effects in the human body. Radionuclides adsorb onto air particles and make their way to humans primarily through inhalation. Naturally-occurring radionuclides, 210Pb and 210Po, are of notable health concern due to their relatively elevated ingestion and inhalation doses. In the current study, activity concentrations of 7Be, 210Pb and 210Po were determined in air particulate matter (PM). PM2.5 was collected on the European side, while PM10 was collected on the Anatolian side of Istanbul. Be-7, 210Pb and 210Po activities were found to be 5.17 ± 2.35, 0.96 ± 0.42; 0.25 ± 0.14 mBq m- 3 in Anatolian side, respectively. Be-7, 210Pb and 210Po activities were found to be 3.81 ± 2.27, 0.62 ± 0.29, 0.29 ± 0.26, mBq m- 3 in European side, respectively. The ratio of 210Po/210Pb was found to be higher (0.47 ± 0.31 for PM2.5 and 0.34 ± 0.27 for PM10) than the global average of 0.1. This result can be explained by the fact that Po is more volatile than Pb and enhanced in the air by the combustion process. Inhalation dose rates of 210Pb and 210Po due to PM10 exposure were calculated to be 7.70 ± 3.30 and 4.05 ± 2.31 µSv year- 1, respectively. Pb-210 bioaccessibility was assessed by the extraction of the particles in simulated lung fluids. Approximately 24.8% of inhaled 210Pb was estimated to be bioaccessible. This study suggests that 210Po and 210Pb activities are partially enhanced in the air particles in Istanbul and should be regularly monitored.

Radiological Assessment of Naturally Occurring Radioactive Material (NORMs) in Selected Building Materials

The use of building materials containing high concentration of naturally occurring radioactive materials (NORMs) may result in the increase of radiation dose rate inside the building. The assessment of radiological hazard in building materials is necessary due to the concern of radiological impact to the people in the building. NORMs present naturally in the environment, but the concentration of radionuclide such as uranium (238U), thorium (232Th) and potassium (40K) may increase due to anthropogenic activities. NORM at certain limit becomes hazardous to environment and human. Thus, the objectives of this study were to determine the level of natural radioactivity in Malaysia’s building materials and to assess the associated radiological risk of selected building materials. The selected material used were sand, soil, cement (white and black), bricks (sand and clay), marble and gravel. The assessment of NORMs in building materials were carried out and the concentrations of were determined using Energy Dispersive X-ray Fluorescence (EDXRF). Activity concentrations of 238U, 232Th and 40K were found to be in the range of 13.93-60.09 Bq/kg, 3.44-128.14 Bq/kg and 2.11-1294.93 % respectively. The external hazard index for all building material samples is under the permissible limits (&lt;1.0) except gravel (1.10). The external hazard index must be less than unity in order to keep the radiation hazard to be negligible. It is suggested that the radiological risk of raw material is predetermined before being used as building material.

Radiological landscape of natural resources and mining: Unveiling the environmental impact of naturally occurring radioactive materials in Ghana's mining areas

This study provides a general observation of the status of naturally occurring radioactive materials (NORMs) distribution in mining and industrial areas of Ghana in order to establish regional and national data on NORMs. The study includes data on radioactivity concentrations of U-238, Th-232, and K-40 in soils and for water concentrations of Ra-226, Th-228, and K-40 from various mining, oil, and gas communities, as well as water sources used for crop farming and farmlands. The average activity concentrations of U-238, Th-232, and K-40 in the soil samples were found to be 59 ± 16 Bq/kg, 48 ± 15 Bq/kg, and 286 ± 57 Bq/kg, respectively. The average concentration of Ra-226, Th-228, and K-40 in the water samples were found to be 1.62 ± 0.33 Bq/L, 2.08 ± 0.53 Bq/L, and 22.36 ± 3.44 Bq/L, respectively. The estimated average annual effective doses from external and internal exposure pathways in soil and water samples were 0.09 mSv/y and 0.54 mSv/y, respectively. The total annual effective dose resulting from both exposure pathways was calculated to be 0.63 mSv/y, which is below the 1 mSv/y dose limit recommended by the International Commission on Radiological Protection (ICRP) for controlling public radiation exposure. Based on the radiological hazard indices, the majority of the soil samples were found to be suitable as building materials as their respective indices were below the limits except for two sample locations and the sludge and scale samples. The average Excess Lifetime Cancer Risk (ELCR) value of the water samples was 1.6 times greater than the recommended value of 1.16 × 10−3, presenting a relatively higher risk to the public of developing cancer. No significant regional differences in the levels of radioactive elements. The regression models demonstrate strong interrelationships between the studied elements, with high R-squared values suggesting a predictable nature of one element’s concentration based on others.

Naturally occurring radioactive materials in offshore infrastructure: Understanding formation and characteristics of baryte scale during decommissioning planning

Contaminants, including naturally occurring radioactive material (NORM) of the 238-uranium and 232-thorium decay series, have been recognized as a global research priority to inform offshore petroleum infrastructure decommissioning decisions. This study aimed to characterize pipeline scale retrieved from a decommissioned subsea well tubular pipe through high-resolution elemental mapping and isotopic analysis. This was achieved by utilizing transmission electron microscopy, Synchrotron x-ray fluorescence, photostimulated luminescence autoradiography and Isotope Ratio Mass Spectrometry. The scale was identified as baryte (BaSO4) forming a dense crystalline matrix, with heterogenous texture and elongated crystals. The changing chemical and physical microenvironment within the pipe influenced the gradual growth rate of baryte over the production life of this infrastructure. A distinct compositional banding of baryte and celestine (SrSO4) bands was observed. Radioactivity attributed by the presence of radionuclides (226Ra, 228Ra) throughout the scale was strongly correlated with baryte. From the detailed scale characterization, we can infer the baryte scale gradually formed within the internals of the tubular well pipe along the duration of production (i.e., 17 years). This new knowledge and insight into the characteristics and formation of petroleum waste products will assist with decommissioning planning to mitigate potential radiological risks to marine ecosystems.

Tinjauan Inventori Daur Hidup dalam Pengelolaan Mineral Ikutan Radioaktif

Naturally-Occurring Radioactive Material (NORM) is generated by several non-nuclear activities or events. Life cycle assessment can be used to evaluate the steps and processes in managing NORM. However, the use of life cycle assessment for NORM is still limited. This paper aims to identify the key considerations when conducting a life cycle inventory analysis for NORM management. The life cycle assessment process includes determining objectives and scope, performing a life cycle inventory analysis, impact assessment, and interpretation. Since NORM is produced by a wide range of activities, it is essential to establish clear objectives and scope from the outset. Analysis of NORM management inventories will vary depending on the physical, chemical, or radionuclide characteristics of the NORM. One of the main challenges in inventory analysis is collecting data and information related to the input, process, and output of a processing unit based on the objectives and scope. Some general considerations that can be used in inventory analysis include determining flow and mass diagrams, location, and equipment data. Flow and mass diagrams show the input, process, and output stages of a processing unit, while location data can be used as a constraint in the life cycle assessment system. Equipment data will contain information regarding the type and number of equipment, equipment performance details, energy requirements, fuel requirements, etc. Inventory analysis can only be carried out accurately and effectively when the objectives and scope of the NORM management life cycle assessment are known. However, even if the processing unit and NORM management characteristics influence the input and output information and data, initial information regarding energy and fuel sources can still be analyzed. Keywords: radioactive minerals, life cycle assessment, NORM analysis, inventory.

Development of a methodology for assessing radiological dose due to use of NORM sludge as fertilizer

In Europe, the general obligation to recycle drives for increased reuse of residues containing Naturally Occurring Radioactive Material (NORM). In agriculture, this has led to the reuse of sludge produced by groundwater filtration facilities as a means of fertilization. In the frame of the RadoNorm project, a methodology was developed for dose assessment of agricultural workers and other members of the public living near agricultural fields in which NORM-containing sludge is applied. Appropriate exposure scenarios were identified and modelled for each relevant NORM decay segment of both U-238 and Th-232 series, as well as for K-40. Dose assessments were performed using the software RESRAD-ONSITE with dose coefficients for external and internal exposure taken from the latest publications from the International Commission on Radiological Protection (ICRP). The objective was to develop a generic methodology to quantify exposure and to obtain screening values – so-called Operational Levels (OLs). These OLs pertain to the activity concentration of natural radionuclides (in terms of kBq kg−1) present in sludge that is reused in agriculture, for which dose criterion of 1 mSv year−1 is complied with. OLs can be used as screening tools by an authority/operator, even non-experts in the field of radiation protection.Results showed that the most critical decay segments are Ra-226+ and Ra-228+, for which OLs of the order of 1 kBq kg−1 were estimated. For all the other radionuclides, the calculated OLs are much higher than the activity concentrations typically found in sludge from water treatment facilities, and the radiological impact expected is well-below 1 mSv year−1. The methodology and results of this study could contribute to the update of the Clearance Levels and discharge levels reported in the European guidelines RP 122 Part II and RP 135, respectively.

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).

Cleaner, sustainable, and safer: Green potential of alkali-activated materials in current building industry, radiological good practice, and a few tips

Alkali-activated materials were prepared from four typical precursors (coal fly ash, granulated blast furnace slag, metakaolin, and brick waste powder) characterized for granulometry, elemental composition, and microstructure. High-resolution gamma-ray spectrometry was used to determine the activity concentration of Naturally Occurring Radioactive Materials (NORM) in all the materials to assess their radiological impact. All the investigated materials have been found to comply with the European dosimetric index (I) according to Directive 2013/59/Euratom. The results suggest the need for an accurate check of radioactivity throughout the mixing phases to prevent I exceedances. The productive chains were also evaluated by principal component analysis.

Assessing the ecological impacts of NORM-contaminated scale on marine infauna using sediment microcosms

Naturally occurring radioactive materials (NORMs) can be found in decommissioned oil and gas infrastructure (e.g. pipelines), including scales. The effects of NORM contaminants from offshore infrastructure on benthic macroorganisms remain poorly understood. To test the potential ecological effects of NORM-contaminated scale, we exposed a marine amphipod, a clam and a polychaete to marine sediments spiked with low level concentrations of barium sulfate scale retrieved from a decommissioned subsea pipe. Only amphipods were included in further analysis due to treatment mortalities of the clam and polychaete. Barium (Ba) and copper (Cu) were elevated in the seawater overlying the spiked sediments, although no sediment metals exceeded guidelines. 210Po was the only NORM detected in the overlying waters while both 210Po and 226Ra were significantly elevated in the scale-contaminated sediments when compared with the control sediments. The whole-body burden of Ba and 226Ra were significantly higher in the scale-exposed amphipods. Using experiment- and scale-specific parameters in biota dose assessments suggested potential dose rates may elicit individual and population level effects. Future work is needed to assess the biological impacts and effects of NORM scale at elevated levels above background concentrations and the accumulation of NORM-associated contaminants by marine organisms.

Physicochemical, Biochemical and Genotoxic Profile of Subchronic Exposure of Wister Rats to Treated Crude Oil Exploration Water

Background: Crude oil exploration water is the major waste product generated from petroleum exploration and production activities and is known to be a complex composition of numerous hazardous chemicals, including large quantities of heavy metals, inorganic, and organic substances and naturally occurring radioactive materials (NORMs).&#x0D; Objectives: This study was designed to investigate the physicochemical, biochemical and genotoxic profile of subchronic exposure of Wister rats to treated crude oil exploration water (TCOEW).&#x0D; Materials and Methods: Fifty rats were randomly assigned to five treatment groups, with ten rats per group, and treated with five concentrations (1%, 5%, 10% and 20%) of TCOEW. Each TCOEW concentration was administered for 90 days ad-libitum as normal drinking water to each group, while the control group was given tap water. Blood, liver, kidney, thymus, spleen and femoral bone of the animals were collected at the end of exposure for biochemical and histological assessments. The pH, conductivity, and turbidity were carried out on-site, while other physicochemical parameters were determined using standard laboratory methods. Data were analysed using descriptive statistics and ANOVA at α 0.05.&#x0D; Results: Treated crude oil exploration water caused a significant (p &lt; 0.05) increase in RBC, PCV and Hb while other hematological and biochemical parameters showed no difference. Also, TCOEW cause a significant increase in polychromatic erythrocytes (PCEs) in genotoxicity test and no major lesion were seen in the histopathology studies. Treated Crude Oil Exploration Water does not comply with FEPA standards of produced water due to high conductivity, salinity and total dissolved solid of the sample. The marked increase in micronuclei polychromatic erythrocyte formation (MNPCE) showed that TCOEW might be genotoxic and this could be responsible for the significant increase RBC, parked cell volume (PCV) and hemoglobin (Hb) observed.&#x0D; Conclusion: Although TCOEW does not totally meet FEPA standard for effluent discharge, it has mild genotoxic effect.

An extendable optical fibre probe survey meter for naturally occurring radioactive material (NORM) and other weak emitters

We have developed a radioluminescence-based survey meter for use in industries in which there is involvement in naturally occurring radioactive material (NORM), also in support of those needing to detect other weak emitters of radiation. The functionality of the system confronts particular shortcomings of the handheld survey meters that are currently being made use of. The device couples a LYSO:Ce scintillator with a photodetector via a polymer optical fibre waveguide, allowing for "intrinsically safe" inspection within pipework, separators, valves and other such component pieces. The small-diameter optical fibre probe is electrically passive, immune to electromagnetic interference, and chemically inert. The readout circuit is entirely incorporated within a handheld casing housing a silicon photomultiplier (SiPM) detection circuit and a microprocessor circuit connected to an LCD display. A 15 m long flexible PMMA optical fibre waveguide is butt coupled to an ABS plastic probe that retains the LYSO:Ce scintillator. Initial tests have included the use of lab-based mixed gamma-ray sources, measurements being made in concert with a reference conventional GM survey-meter. Characterization, via NORM sources at a decontamination facility, has shown useful sensitivity, covering the dose-rate range 0.10- to 28 µSv h−1 (R-squared 0.966), extending to 80 µSv/h as demonstrated in use of a Cs-137 source. The system is shown to provide an effective tool for detection of radioactivity within hard to access locations, in particular for sources emitting at low radiation levels, down to values that approach background.

Radon Flux Measurement System.

Disposal of naturally occurring radioactive material (NORM) and technologically enhanced naturally occurring radioactive material (TENORM) waste in the State of Oregon is prohibited unless it can be demonstrated that the material is nonradioactive as defined by its radionuclide content and potential for emission into the environment. It was determined that a radon flux on the surface of the waste no greater than 0.37 Bq m -2 s -1 would meet this requirement. This article provides a method to estimate the radon flux through indirect measurement of the radon mass exhalation rate. It describes a device that consists of a radon accumulation chamber coupled with a continuous radon monitor and software to process the results and calculate the radon mass exhalation rate and radon flux for an unknown sample of approximately 500 g. The chamber system was tested with a uranium ore sample.

Distribution of natural radionuclides in NORM samples from North Abu Rusheid area, Egypt

The North Abu Rusheid area in Egypt is a well-known high background natural radiation area (HBNRA) due to the existence of naturally occurring radioactive materials (NORMs) in mylonitic rocks. In this study, 27 rock samples were selected for dose estimation studies. 238U and 232Th were measured using inductively coupled plasma mass spectrometry (ICP-MS) and 40K was measured using sodium iodide (thallium) gamma-ray spectroscopy. The ranges of activity concentrations (Bq/kg) of 238U, 232Th and 40K in the samples varied from 270 ± 2 to 2120 ± 29, 350 ± 2 to 1840 ± 27 and 20 ± 2 to 1390 ± 35 with mean values of 980 ± 349, 770 ± 351, and 640 ± 402 Bq/kg, respectively. The radiological hazard parameters were estimated from activity concentrations of 238U, 232Th and 40K and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) values. The present study revealed that the hazard parameters were several times higher than the worldwide averages. The U/Th concentration ratio ranged from 0.7 to 3 and could be attributed to the presence of kasolite, uranothorite, zircon, and columbite in mylonitic rocks. From the radiological protection viewpoint, it is necessary to monitor natural radionuclides in these rocks prior to their use in residential and commercial construction materials.

Measurements of Radiometric Concentrations for &lt;sup&gt;222&lt;/sup&gt;Ra, &lt;sup&gt;238&lt;/sup&gt;U, &lt;sup&gt;232&lt;/sup&gt;Th and &lt;sup&gt;40&lt;/sup&gt;K in Soil Samples from Two Uranium Mines’ Stockpiles, Erongo Region, Namibia

&lt;p&gt;The continuous exposures from radiations to human population has led to research studies on evaluating the radioactivity concentrations in most parts of the world. Naturally occurring radioactive materials (NORM) have been greatly regarded as the chief sources of both terrestrial and cosmological radiations. In this study a high-purity germanium well detector was used to measure the activity concentrations of samples from mines 1 and 2 considered in the study. The measured average activity concentration for &lt;sup&gt;226&lt;/sup&gt;Ra, &lt;sup&gt;238&lt;/sup&gt;U, &lt;sup&gt;232&lt;/sup&gt;Th and &lt;sup&gt;40&lt;/sup&gt;K in mine 1 were estimated at 2546±10, 557±13, 215±2 and 1079±26 Bq.kg&lt;sup&gt;-1&lt;/sup&gt;, respectively. For mine 2, the estimated average values of the radionuclides of &lt;sup&gt;226&lt;/sup&gt;Ra, &lt;sup&gt;238&lt;/sup&gt;U, &lt;sup&gt;232&lt;/sup&gt;Th and &lt;sup&gt;40&lt;/sup&gt;K were calculated as 4414±27, 842±29, 436±5 and 2225±52 Bq.kg&lt;sup&gt;-1&lt;/sup&gt;, respectively. The high concentration of radium in samples contributed to high rate of radon emanation into the atmosphere, ground and surface water as well and, if no remedial measures are put in place, this may contribute to plants, animals and eventually human exposures in the region. The study concludes that mine tailings contribute to an increase in background radiation in the environment due to the fact that they are uncovered and deposited in the open environment, resulting in wind-blown &lt;sup&gt;226&lt;/sup&gt;Ra carrying dust entering nearby residential dwellings. The exposures rates could also be increased by other possible transfer pathways, such as ingestions, inhalations and external gamma radiations. Mining companies are urged to decrease windblown atmospheric exposure by using water tanks mounted on mining equipment to sprinkle on top of the soil or covering the tailings with canvas sheet.&lt;/p&gt;

The spatiotemporal variation, background, and baseline activities of radionuclides in the soil of Aragats Massif (Armenia).

The present study was performed to reveal the distribution patterns and spatiotemporal changes of radionuclides in the soil of the highest mountain of Armenia: Aragats Massif. In this regard, two surveys were implemented in 2016-2018 and 2021 with an altitudinal sampling strategy. The activities of radionuclides were determined by gamma spectrometry system with HPGe detector (CANBERRA). Correlation and linear regression analysis were applied to determine the dependence of radionuclides' distribution from altitude. Classical and robust statistical methods were used to assess the local background and baseline values. In two sampling profiles, the spatiotemporal variation of radionuclides was studied. A significant correlation was revealed between 137Cs and altitude pointing to global atmospheric migration as a primary source of 137Cs in Armenian environment. The predicted values of regression model revealed a 0.08-Bq/kg and 0.03-Bq/kg increase of 137Cs in each m on average, for the old and new survey, respectively. The assessment of background activities of NOR (naturally occurring radionuclides) enables setting the local background for 226Ra, 232Th, and 40K in soils of Aragats Massif: 831.3 ± 20.2Bq/kg and 540.6 ± 18.3Bq/kg for 40K, 85.5 ± 3.1Bq/kg and 27.7 ± 2.6Bq/kg for 226Ra, and 66.8 ± 3.2 and 46.4 ± 3.0Bq/kg for 232Th, respectively, for the years of 2016-2018 and 2021. 137Cs baseline activity was estimated by altitude: 350 ± 3.7Bq/kg and 108 ± 2.5Bq/kg, respectively, for the years of 2016-2018 and 2021.

Naturally Occurring Radioactive Materials in the Soil of Near Basra Oil Company Fields

The present study aimed to determine the levels of contamination with Natural Occurring Radioactive Materials NORM in one of the south oil company fields. The external gamma absorbed dose rate Dγ measured in units of µSv/h was caused by gamma rays of Radium 222, Radium 228 (Thorium 232), and Potassium 40, respectively. The largest value is 9.220 µSv/h. It was found that the highest specific activity (concentration) for Radium 226 is 1136 Bq/kg and the lowest is 0.06 and the highest specific activity for Radium 228 is 721 Bq/kg and the lowest is 0.02 Bq/kg. As for Radium 224, its highest specific activity is 631 Bq/kg and the lowest is 0.02 Bq/kg. Radium-228 is higher than that of Radium-224 or Radium-226, as the Radium-224 is from the Uranium-232 series, and the Radium-228 and Radium-224 are from the Thorium-232 series, meaning that the percentage of the daughters of the Thorium chain is lower than the percentage of the daughters of the Thorium chain Uranium, because the half-life of Radium-226 is 1600 years, which is greater than the half-life of Radium-228, which is 5.75 years. A comparison was made between the local results with the results of soil in Amman. Methods of treating pollution with natural radioactive materials in the oil industry were also discussed.