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1.
Appl Radiat Isot ; 207: 111266, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38461629

RESUMO

Brazil is the fourth largest cement consumer in the world and the largest producer in Latin America, around 1.3% of global production. The main inputs in the manufacture of cement are limestone and clay. Few studies have been carried out in the country on the risk of these materials used in civil construction. Therefore, the objective of this present work is to evaluate the radiological danger that they can present to society. Gamma spectrometry analysis on 16 samples of different brands of cement used as construction material in Rio de Janeiro (Brazil) was performed in this study, using an HPGe detector and the Genie 2000 data acquisition software. Samples were set to count for an accumulation time of 14,400 s (4 h) and all measurements were corrected to eliminate background and backscattering. Activity concentrations are determined for 226Ra was from (41.2 ± 1.6 to 174.9 ± 3.9) Bq kg-1, 232Th was from (15.7 ± 0.5 to 43.1 ± 0.7) Bq kg-1 and 40K was from (82.6 ± 7.2 to 254 ± 17) Bq kg-1. To assess radiological health risks: mean values of Radium Activity Equivalent 150.0 ± 3.4 Bq kg-1, Annual Gonadal Dose Equivalent 468 ± 11 µSv year-1 and Lifetime Excess Cancer Risk (ELCR) 2.42 ± 0.06 were calculated. Total Absorbed Dose Rates ranged from 72.2 ± 1.7 to 225.1 ± 5.2 nGy h-1. The damage to collective health was also estimated from the annual effective dose rates with an estimated total cost of damage to health of US$ 130 million. Values are generally within global limits reported by UNSCEAR.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Radioisótopos de Potássio/análise , Tório/análise , Monitoramento de Radiação/métodos , Brasil , Materiais de Construção/análise , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama
2.
Isotopes Environ Health Stud ; 60(2): 213-225, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38372986

RESUMO

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.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Humanos , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Tório/análise , Bangladesh , Rádio (Elemento)/análise , Solo , Radioisótopos de Potássio/análise , Espectrometria gama
3.
J Environ Radioact ; 273: 107382, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38266319

RESUMO

Advances in the development of gamma-ray spectrometers have resulted in devices that are ideal for use in conjunction with the increasingly reliable systems of autonomously flying uncrewed aerial vehicles (UAVs) that have recently become available on the market. Airborne gamma-ray spectrometry (GRS) measurements have many different applications. Here, the technique is applied to a former uranium mining and processing site, which is characterized by relatively low specific activities and, hence, low count rates, requiring relatively large detectors and correspondingly big size UAVs. The future acceptance of the use of such UAV-based GRS systems for radionuclide mapping depends on their ability to measure absolute specific activities of natural radionuclides such as U-238 in near-surface soil that are consistent with the results of established and proven ground-based systems. To determine absolute specific activities on the ground, the gamma radiation data from airborne detectors must be corrected for attenuation caused by the flight altitude above ground. In recent years, mathematical procedures for altitude correction have been developed, that are specifically tailored to the working range of several tens of meters typical for UAVs. However, very limited experimental validation of these theoretical approaches is available. A very large dataset consisting of about 3000 UAV-based and 19,000 backpack-based measurements was collected at a low-grade uranium ore dump in Yangiabad, Uzbekistan. We applied different geostatistical interpolation methods to compare the data from both survey techniques by upscaling backpack data to airborne data. Compared to backpack systems, UAV-based systems have lower spatial resolution, so measurements average over larger areal units (or in geostatistical terminology: "spatial support"). Taking into account the change in spatial support, we illustrate that (1) the UAV-based measurements show good agreement with the upscaled backpack measurements and that (2) UAV surveys provide good delineation of contrasts of the relatively smooth U-238 specific activity distribution typical for former uranium mining and processing sites. We are able to show that the resolution of UAV-based systems is sufficient to map extended uranium waste facilities.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Urânio , Urânio/análise , Monitoramento de Radiação/métodos , Poluentes Radioativos do Solo/análise , Espectrometria gama
4.
Radiat Prot Dosimetry ; 200(2): 201-205, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38044801

RESUMO

Natural radioactive materials in certain conditions can get to hazardous radiological level. The aim of the present work was to evaluate the natural activity concentration from sampled building materials collected from different locations in Babadogo Estate within Nairobi City County. The analysis done using gamma ray spectrometer, which was put into action for spectral data acquisition and then analysis. The activity concentration levels of 238U, 232Th and 40K for the selected samples of building materials was measured by the use of gamma ray spectrometry method. The analyzed data compared with the standard acceptable values. The activity concentration in 40K varied from 55 ± 3 to 2647 ± 132 Bq kg-1, giving an average (sum of all values divided by 33) value of 831 ± 42 Bq kg-1; 238U varied from 39 ± 2 to 3602 ± 180 Bq kg-1, giving average figures of 378 ± 19 Bq kg-1 and 232Th ranged from 5.000 ± 0.300 to 4213 ± 211 Bq kg-1, giving average figure of 290 ± 15 Bq kg-1. The calculated average figures for activity concentration surpassed the world average values of 420, 33 and 45 Bq kg-1 in 40K, 238U and 232Th, respectively.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Urânio , Tório/análise , Urânio/análise , Quênia , Materiais de Construção/análise , Espectrometria gama , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise
5.
Appl Radiat Isot ; 204: 111136, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38064806

RESUMO

The transfer factor (TF) of naturally occurring radioactivity between soil and olive mill pomace (OMP) was calculated in this study. Nine samples were collected from three locations in north Jordan. The study focused on calculating the 226Ra, 232Th, 40K, and 137Cs activity concentrations in both soil and OMP samples using high-purity germanium (HPGe) gamma-ray spectrometry. The average activity levels in the soil samples were determined to be 24.0±10.1, 31.3±9.1, 323.7±68.4, and 1.0±0.4 (Bqkg-1), respectively. In the OMP samples, the average activity levels of 226Ra, 232Th, and 40K were 6.7±1.8, 3.2±1.2, and 185.5±56.6 (Bqkg-1), respectively, while no trace of 137Cs was detected. The activity concentrations of 226Ra, 232Th, and 40K in the soils and OMP samples are within the average worldwide ranges. The calculated values of the TF geometric mean (geometric standard deviation) for 226Ra, 232Th, and 40K were determined to be 0.35 (0.2), 0.11 (0.05), and 0.59 (0.19), respectively. This research offers valuable information about the behavior and movement of radionuclides in the environment.


Assuntos
Olea , Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Fator de Transferência/análise , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Radioisótopos de Césio/análise , Espectrometria gama , Solo/química
6.
J Environ Radioact ; 272: 107357, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159463

RESUMO

The International Monitoring System (IMS) is a unique global network of sensors, tuned to measure various phenomenology, with the common goal of detecting a nuclear explosion anywhere in the world. One component of this network collects measurements of radioactive particulates and gases (collectively known as radionuclides) present in the atmosphere; through this, compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) can be verified. The radionuclide sub-network consists of 120 sensors across 80 locations, supported by 16 measurement laboratories. All radionuclide stations make use of a form of γ-ray spectroscopy to measure radionuclides from samples; this remains largely unchanged since the network was first established 25 years ago. Advances in sampling and spectroscopy systems can yield improvements to the sensitivity of the network to detect a nuclear explosion. This paper summarises the status of the IMS radionuclide network, the current suite of technology used and reviews new technology that could enhance future iterations, potentially improving the verification power of the IMS.


Assuntos
Poluentes Radioativos do Ar , Monitoramento de Radiação , Monitoramento de Radiação/métodos , Poluentes Radioativos do Ar/análise , Radioisótopos/análise , Espectrometria gama , Cooperação Internacional , Radioisótopos de Xenônio/análise
7.
Environ Monit Assess ; 195(12): 1412, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37921876

RESUMO

This study investigates soil radioactivity at the Pomuk gas field in Uzbekistan, a region with history of underground nuclear activity. Using a NaI (Tl) scintillation gamma spectrometer, soil samples were analyzed for concentrations of 232Th, 226Ra, 40K, and 137Cs. Concentrations were found to be in the range of 19.0-31.0 Bq/kg for 232Th, 12.0-32.0 Bq/kg for 226Ra, 450.0-634.0 Bq/kg for 40K, and 2.4-11.0 Bq/kg for 137Cs. Surface radon flux density was measured using a coal sorbent-based passive method, with values ranging from 26.1 to 79.0 mBq/m2s. Mean activity values for radium equivalent (Raeq) and gamma representative level index (Iγ) were calculated to be 75.2-96.5 Bq/kg and 0.3-0.4 Bq/kg, respectively. The absorbed airborne gamma dose rates (GDR) varied between 41.0 and 52.0 nGy/h, while annual effective dose rates (AEDR) were 0.3-0.4 µSv/year. The radiological risk assessment indicates the area is within safe limits for the population and environment, providing a foundation for future radiological monitoring programs.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Solo , Uzbequistão , Explosões , Campos de Petróleo e Gás , Monitoramento Ambiental , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise , Tório/análise , Espectrometria gama
8.
Isotopes Environ Health Stud ; 59(4-6): 554-566, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37960925

RESUMO

This study aimed to evaluate natural radioactivity levels and hazards of radionuclides 232Th, 226Ra and 40K in soil samples taken from 15 locations in the Lega Dembi gold mining, Oromia, Ethiopia, using gamma-ray spectroscopy coupled with an HPGe detector. It was observed that the respective mean specific activities for 226Ra, 232Th and 40K determined in the mining site were 23.87 ± 0.7, 52.5 ± 1.8 and 391.62 ± 11.35 Bq/kg, and 8.89 ± 0.4, 13.83 ± 0.6 and 423.68 ± 9.5 Bq/kg in the living areas. The specific activity of 232Th was above the permissive limit in the mining site, while for 226Ra and 40K were within the limit. The specific activity of 40K in the living area was observed to be above the permissive limit. The calculated value of radiation hazards parameters; radium equivalent activity (Raeq), internal and external hazards indices (Hin) and (Hex), the mean annual effective dose (AED), and gamma representative indices (Iγ) were within permissively limit. The mean absorbed dose rate in the mining site was above the recommended safety limit. The total annual gonadal dose equivalent value was found to be 494.8 ± 8.7 µSv/a in the mining site. This value was also above the permissively.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Etiópia , Ouro , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Radioisótopos/análise , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise , Mineração
9.
Environ Monit Assess ; 195(11): 1307, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37831213

RESUMO

Radioactive elements and their impact on the environment and the food chain, including humans, are a matter of major concern, for which appropriate investigations should be performed. The priority is to examine the concentration of radioactive substances in mineral and bottled spring water. This task aims to analyze the quality of 12 conditioned mineral waters by determining their main radionuclides concentrations, such as 238U, 232Th, and 40K. The identification and the quantification of these radionuclides are carried out by their progeny (except the 40K) by using a NaI(Tl) detector coupled with a multichannel analyzer (MCA) and connected to a computer. The activity measured in all samples varied from 0.95 to 3.38 mBq.L-1 with an average of 1.94 mBq.L-1; from 1.55 to 3.56 mBq.L-1 with an average of 2.46 mBq.L-1; and from 200.68 to 269.19 mBq.L-1 with an average of 236.6 mBq.L-1, for 238U, 232Th, and 40K, respectively. To compare the combined radiological effects of radionuclides present in water, a particular factor Ra(eq) is used. This study showed that the maximum value of Ra(eq) is 27.54 mBq.L-1, which is far below the activity limit of 370 mBq.year-1 set by the Organization of Economics and Development (OECD). Concerning the effective annual dose, the following maximums were measured: 1.61 µSv.year-1, 1.133 µSv.year-1, and 0.925 µSv.year-1 for infants, children, and adults, respectively. These values are even smaller than the dose recommended by the WHO which is 100 µSv.year-1. Regarding the excess lifetime cancer risk index, a maximum of 5.63 × 10-6 is found. This index value is still less than that proposed by James, namely 2.5 × 10-3. Thus, the quality of the studied samples respects the radiological international safety and health limits.


Assuntos
Água Potável , Monitoramento de Radiação , Radioatividade , Poluentes Radioativos da Água , Lactente , Criança , Adulto , Humanos , Água Potável/química , Poluentes Radioativos da Água/análise , Espectrometria gama , Monitoramento de Radiação/métodos , Radioisótopos/análise
10.
Environ Monit Assess ; 195(10): 1147, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37668825

RESUMO

The activity concentration of 40K in soils of Rostov agglomeration was studied. Natural and anthropogenically modified soils of Rostov agglomeration were studied: Haplic Chernozems, Haplic Chernozems (Technic), Urbic Technosols. Activity concentration 40K in soils was measured by gamma-spectrometric method of radionuclide analysis. The total mass fraction of K2O was determined by X-ray fluorescence method on a Spectroscan MAKS-GV instrument. Knowing the total mass fraction of K2O, we calculated its potential radioactivity based on the fact that one gram of natural potassium has an activity concentration of 28.5 Bq. Comparison of the two methods allows estimating the involvement of 40K in biogenic cycles. No significant differences between the actual and calculated activity concentration of 40K in the soil-forming rock were revealed, while in horizons A and B the calculated activity is significantly higher. At the same time, there are no reliable differences between native and their buried analogs. The direct influence of the granulometric composition on the activity concentration of 40K was not established, but in the urban horizons with lightened granulometric composition the average activity of 40K is the lowest by reliably significant values when comparing this index with native, buried horizons and the group of heavy urban horizons. This implies that 40K is more actively involved in biogenic cycles than its stable isotopes. The burial under urban deposits is accompanied by a weak change in the activity concentration of 40K in the profile, while the difference between genetic horizons is leveled out.


Assuntos
Monitoramento Ambiental , Potássio , Solo , Espectrometria gama , Coloração e Rotulagem
11.
Appl Radiat Isot ; 200: 110939, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536028

RESUMO

In this study, natural radioactivity levels (226Ra, 232Th, and 4 K) of some medicinal plant samples with known anti-oxidative properties, which are frequently consumed by animals and humans, were obtained from Ankara province and its surroundings (Mamak, Kizilcahamam, Beypazari, Kahramankazan, and Polatli districts) were determined using a thallium-doped sodium iodide NaI(Tl) gamma spectrometry. By using the determined natural radioactivity concentrations in the collected plant samples, the number of radiological doses that people could be exposed by consuming these plants was calculated. As a result of the study, 226Ra, 232Th, and 4 K radioactivity concentration ranges of the plant samples were found be 14.69 ± 1.27-59.08 ± 3.12 Bq kg-1, 1.78 ± 0.04-50.05 ± 2.76 Bq kg-1 and 207.24 ± 34.09-826.13 ± 25.40 Bq kg-1, respectively. The highest 226Ra, 232Th, and 4 K activity concentrations were measured in Astragalus densifolius subsp. ayashensis (Kahramankazan), Astragalus kochakii (Kahramankazan) and Rumex patientia (Patience Dock) (Kahramankazan) plants, respectively. The lowest 226Ra, 232Th and,4 K activity concentration plants were determined respectively as Rumex patientia (Mamak), Lavandula angustifolia (Kizilcahamam), and Astragalus acikirensis (Polatli). The establishment and routine repetition of environmental radioactivity monitoring programs in each region are important for human and animal health, and the results of this study gain importance for Ankara and its surroundings in terms of environmental health.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Humanos , Radioisótopos/análise , Monitoramento de Radiação/métodos , Turquia , Espectrometria gama/métodos , Poluentes Radioativos do Solo/análise , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise , Tório/análise
12.
Mar Pollut Bull ; 194(Pt B): 115346, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37536080

RESUMO

The Dispersal profile of the radioisotopes (226Ra, 232Th, 235U, 40K, 137Cs) along with potentially toxic elements (Cd, Co, Cr, Cu, Ni, Pb, V, Zn, and Hg) in the sediments around the Novaya Zemlya was determined. The task was fulfilled with the aid of HPGe gamma spectrometry, inductively coupled plasma optical emission spectroscopy, DMA-80 Direct Mercury Analysis System, X-ray diffraction and statistical tools. At most of the locations, the radionuclides activity was higher than the world average activity concentration for the respective nuclei, 40K being the most abundant. From all the potentially toxic elements detected, Cr and Ni were usually observed on higher levels compared to their background values, indicating the probability of the detrimental biological effects. Thus, the present situation at the studied area might be a threat to the neighboring marine life.


Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Monitoramento Ambiental/métodos , Metais Pesados/análise , Mercúrio/análise , Espectrometria gama , Sedimentos Geológicos/química , Medição de Risco , China , Poluentes Químicos da Água/análise
13.
Isotopes Environ Health Stud ; 59(4-6): 529-538, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37565800

RESUMO

Radium-226 detection in sediment samples is generally executed by means of gamma-ray spectrometry. Data evaluation relies (besides the 186.2 keV 226Ra gamma peak) on the combined analysis of major gamma peaks that are produced by the short-lived radon (222Rn) daughters 214Pb and 214Bi. Precondition for this detection approach is equilibrium decay of all members of the decay chain between 226Ra and 214Bi. In closed systems, this equilibrium is reached after about five half-lives of 222Rn (19 days). However, a closed system can only be guaranteed if the capsule which contains the sample prevents diffusive escape of radon. Such radon-tightness cannot be guaranteed for a wide range of plastic materials. Due to its polymer structure, plastic material generally tends to allow radon diffusion and hence radon loss from the sample resulting in a disturbance of the required decay equilibrium. The paper introduces an approach that allows quantifying radon loss from sample capsules by direct radon measurements using mobile radon detection equipment. The experimental findings are supported by theoretical considerations. An examined alternative approach based on the offset of the 186.2 keV data point from an efficiency function that is calculated exclusively from short-lived radon progeny peaks in the gamma-ray spectrum did not prove to be applicable due to a lack of supporting peaks in the low-energy section of the spectrum.


Assuntos
Poluentes Radioativos do Ar , Monitoramento de Radiação , Rádio (Elemento) , Radônio , Radônio/análise , Poluentes Radioativos do Ar/análise , Produtos de Decaimento de Radônio/análise , Espectrometria gama/métodos , Rádio (Elemento)/análise , Monitoramento de Radiação/métodos
14.
Mar Pollut Bull ; 194(Pt B): 115367, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37567130

RESUMO

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


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Radioisótopos/análise , Rádio (Elemento)/análise , Recursos Naturais , Tório/análise , Poluentes Radioativos do Solo/análise , Radioisótopos de Potássio/análise , Espectrometria gama
15.
J Environ Radioact ; 266-267: 107240, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37418811

RESUMO

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.


Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Espectrometria gama/métodos , Egito , Tório/análise , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Rádio (Elemento)/análise
16.
Appl Radiat Isot ; 199: 110918, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37406489

RESUMO

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


Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Animais , Pós , Iraque , Leite/química , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Rádio (Elemento)/análise , Tório/análise , Radioisótopos de Potássio/análise , Espectrometria gama
17.
Environ Monit Assess ; 195(7): 851, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37326918

RESUMO

Measurements of radionuclides' activities in air, water, and soil give clues about the anthropogenic activities in the region, and imperative to assess the overall radiological risk for individuals. Such an investigation was carried out to characterize the soil activities in the region hosting a research center, and to calculate the associated elements of radiological risk in terms of radiation doses and hazard indices. The soil samples were collected within the radius of 10 km in local area, Nilore, and analysed for activity using a high-purity germanium (HPGe) gamma spectrometric system. In all samples, only the basic nuclides, contributing to terrestrial activity, i.e., 40 K, 232Th, 226Ra, and 137Cs, were observed within the detectable limits of activity. The distribution of the data set and the correlation between the measured activities were studied with the use of the principal component analysis (PCA). The measured average specific activities of 226Ra, 232Th, 40 K, and 137Cs were 40.65 ± 9.84 Bq/kg, 59.31 ± 16.53 Bq/kg, 528.24 ± 131.18 Bq/kg, and 5.16 ± 4.56 Bq/kg respectively. The corresponding dose rate in air was found to be 76.63 ± 18.39 nGy/h, which is slightly higher than the world median value of 51 nGy/h calculated from concentration of terrestrial radionuclides in soil but falls within the world average value range of outdoor external exposure of 18-93 nGy/h obtained through direct measurement, and therefore not harmful for the living species. The standard hazard indices for all soil samples such as radium equivalent activity ([Formula: see text]), external hazard index (Hex), and internal hazard index (Hin) were also found within safe limits for the soil to be used as construction of building material. This investigation led to conclusion that the soil activities are consistent with the usual background level of terrestrial activities, and their associated dose rates are well within the safe limits for public.


Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Humanos , Espectrometria gama , Monitoramento de Radiação/métodos , Paquistão , Poluentes Radioativos do Solo/análise , Radioisótopos de Césio/análise , Rádio (Elemento)/análise , Solo/química , Medição de Risco , Tório/análise , Radioisótopos de Potássio/análise
18.
Environ Sci Pollut Res Int ; 30(27): 70937-70949, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37160855

RESUMO

This study focused on the determination of natural (238U, 232Th, and 40K) and artificial (137Cs) radionuclide concentrations both in 55 sediment samples collected from various depths in the Bosphorus and 5 soil samples from the coastline of the Bosphorus, Istanbul, using gamma-ray spectrometry with an HPGe detector. The mean activity concentrations of natural 238U, 232Th, and 40K and anthropogenic 137Cs were determined to be 11.41 ± 0.21 Bq kg-1, 6.87 ± 0.16 Bq kg-1, 369.61 ± 3.41 Bq kg-1, and 6.54 ± 0.11 Bq kg-1, respectively, in the sediment samples. The average activity concentrations of 238U, 232Th, 40K, and 137Cs radionuclides in the soil samples were also measured to be 11.65 ± 0.18 Bq kg-1, 9.55 ± 0.15 Bq kg-1, 369.43 ± 3.09 Bq kg-1, and 4.57 ± 0.09 Bq kg-1, respectively. Radiological contour maps based on the activity concentrations of natural and artificial radionuclides in the sediment samples for the Bosphorus, Istanbul, were created. The total annual effective doses due to soil samples were calculated to be 34.58 µSv y-1.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Poluentes Radioativos do Solo/análise , Radioisótopos de Césio/análise , Espectrometria gama/métodos , Solo
19.
Appl Radiat Isot ; 198: 110853, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37216724

RESUMO

Gamma detector detection technology based on NaI(Tl) scintillation crystal has become a popular research topic and has been applied in the field of marine radioactive environment automatic monitoring because of its advantages of low power consumption, low cost and strong environmental adaptability. However, insufficient energy resolution of the NaI(Tl) detector and great Compton scattering in the low-energy region caused by the abundance of natural radionuclides in seawater hinder the automatic analysis of radionuclides in seawater. This study adopts the combination of theoretical derivation, simulation experiment, water tank test and seawater field test, establishing an effective and feasible spectrum reconstruction method. The measured spectrum in seawater is regarded as the output signal formed by the convolution of the incident spectrum and the detector response function. The acceleration factor p is introduced to construct the Boosted-WNNLS deconvolution algorithm, which is used to iteratively reconstruct the spectrum. The analysis results of the simulation test, water tank test and field test meet the radionuclide analysis speed and accuracy requirements for the in-situ automatic monitoring of seawater radioactivity. The spectrum reconstruction method in this study converts the physical problem of insufficient detection accuracy of spectrometer in the practical application into a mathematical problem of deconvolution solution, restores the original radiation information in seawater, and improves the resolution of the seawater gamma spectrum.


Assuntos
Monitoramento de Radiação , Radioatividade , Monitoramento de Radiação/métodos , Espectrometria gama/métodos , Método de Monte Carlo , Água do Mar/análise , Radioisótopos/análise , Água/análise , Raios gama
20.
Mar Pollut Bull ; 192: 114992, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37182242

RESUMO

Sediment and seafood samples were collected from Makoko Lagoon, Lagos state, Nigeria. Gamma-ray spectrometry was used to determine the activity concentrations of 40K, 226Ra and 232Th in the samples. The average activity concentrations of 40K, 226Ra and 232Th in the sediment were 41.04 ± 6.41, 10.15 ± 3.19 and 4.39 ± 2.10 Bq kg-1, respectively, while the annual effective dose was 0.01 mSv/year. In seafood, the average activity concentrations of 40K, 226Ra and 232Th were 15.66 ± 8.07, 1.72 ± 1.51 and 1.93 ± 0.30 Bq kg-1, respectively. The cumulative effective ingestion dose obtained ranged from 0.016 µSv/year (giant prawn) to 1.08 µSv/year (Parrotgrunt). The mean activity concentrations and absorbed dose rate in sediment were below the worldwide average values. The cumulative dose from the ingestion of seafood was also significantly low. Sediment and seafood from the lagoon in Makoko pose no health risk from a radiological point of view to the population.


Assuntos
Monitoramento de Radiação , Poluentes Radioativos do Solo , Nigéria , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama , Alimentos Marinhos/análise , Monitoramento de Radiação/métodos
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