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1.
Environ Monit Assess ; 196(11): 1133, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39476202

RESUMO

The Higher and Tethys Himalayan region of NW-Himalaya is less explored from the natural radioactivity mapping assessment, though geologically and tectonically, this region is still active. The concentration of primordial radionuclides (226Ra, 232Th, and 40 K) in rock samples of the Manali-Leh Highway region of the Himalayas is determined in the present study using the HPGe detector. The radiological hazard parameters are also estimated in terms of radium equivalent activity (Raeq), annual effective dose (Ein and Eout), hazard indices (Hin, Hex, Hα, and Hγ), and gamma absorbed dose rate. SEM-EDS analysis was used to understand the mineralogical composition of the rocks. The activity concentration of 226Ra, 232Th, and 40 K radionuclides varies from 1.4 ± 0.9 to 25.3 ± 1.2, 0.7 ± 0.5 to 59.6 ± 1.6, and BDL (below detection limit) to 830.3 ± 45.7 Bq kg-1, with an average value of 13.0 ± 1.0, 21.7 ± 1.0, and 243.7 ± 25.2 Bq kg-1, respectively. The average of Raeq in the study region lies within the safe limit of 370 Bq kg-1. The hazard indices have values < 1, indicating no radiological hazards to the population from the rocks. The annual effective dose also has values less than the global average value. This study revealed that the rocks of the Higher Himalayan region have a higher concentration of natural radioactivity, while the Tethys Himalayan rocks have lower concentrations of 226Ra, 232Th, and 40 K radionuclides. The origin of rocks from different lithologies may be the reason for the natural radioactivity variation. The average concentrations of primordial radionuclides in the region are within the world average indicating that the rocks of the region are safe to be used for different purposes.


Assuntos
Radiação de Fundo , Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Tório , Índia , Rádio (Elemento)/análise , Tório/análise , Poluentes Radioativos do Solo/análise , Radioisótopos de Potássio/análise
2.
Health Phys ; 127(6): 730-733, 2024 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-39297777

RESUMO

ABSTRACT: Objectives: To analyze the effects of normal x-ray inspection, machine washing, and machine drying on thermoluminescent dosimeter (TLD) measurements during external individual monitoring and to provide suggestions for determining individual monitoring measurements under the mentioned abnormal situations. In this study, we focused on three abnormal situations: x-ray inspection, machine washing, and machine drying, which are common in external individual dose monitoring. We measured and compared the doses from TLD with and without 11, 23, 35, and 50 security checks. We used different radiation sources to expose the TLDs before or after machine washing with or without hot drying. The three radiation sources are natural background radiation, 137 Cs γ rays, and 320 kVp x-rays. We measured 20 TLDs for each situation. The average doses for the TLDs with 11, 23, 35, 50 security checks are 27.7 µGy, 59.7 µGy, 84.1 µGy, and 121.0 µGy, respectively. We measured an average dose of 2.5 µGy per exposure. The doses showed no significant difference between different times of washing with different radiation sources, natural background radiation, 137 Cs, or x-ray exposures. There was also no significant difference between the dose coming from the controlled group, drying at 60 °C and 90 °C for 1 h after exposure to 137 Cs γ rays and 320 kVp x-rays. The common machine drying under the temperature of 90 °C did not affect TLD measured doses.


Assuntos
Doses de Radiação , Dosimetria Termoluminescente , Dosimetria Termoluminescente/métodos , Dosimetria Termoluminescente/instrumentação , Humanos , Dosímetros de Radiação , Raios X , Monitoramento de Radiação/métodos , Monitoramento de Radiação/instrumentação , Radioisótopos de Césio/análise , Exposição à Radiação/análise , Radiação de Fundo
3.
Radiat Prot Dosimetry ; 200(15): 1450-1461, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39242111

RESUMO

The objective of the study is to evaluate natural radioactivity and its radiological impact on the health of the populace within Cape Coast North. Soil and water samples were taken and analysed using a high purity germanium (HPGe) detector. Results for the average activity concentrations of 226Ra, 232Th, and 40K in soil samples range from 15.0 to 60.8 Bq/kg with a mean of 20.9 ± 7.2 Bq/kg, 16.3 to 97.2 Bq/kg with a mean of 43.8 ± 2.4 Bq/kg, and 4.7 to 411.4 Bq/kg with an average of 140.6 ± 4.2 Bq/kg, respectively. The absorbed dose rate in air and outdoor annual effective dose to the public were estimated to be 46.6 nGyh-1 and 0.1 mSv, respectively, which fell below the recommended average. The average activity concentrations of 226Ra, 232Th, and 40K in water samples were 1.4, 0.4, and 1.2 Bq/L, respectively. The annual effective dose is 0.4 mSv, which is greater than the WHO recommended level of 0.1 mSv/y.


Assuntos
Radiação de Fundo , Radioisótopos de Potássio , Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Tório , Poluentes Radioativos da Água , Gana , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Tório/análise , Poluentes Radioativos da Água/análise , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise , Humanos , Doses de Radiação
4.
Int J Radiat Biol ; 100(11): 1517-1526, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39321323

RESUMO

PURPOSE: To study the adaptation of bacteria to the natural γ-background of mountains and anthropogenic emissions from nuclear power plants; to establish the main factors of variability and speciation of bacteria. METHOD: Analysis of materials on the radiation background and its impact on living organisms in the landscape of Armenia, calculation of the absorbed dose by microbes due to rock radiation. RESULTS: The review shows the death, reproduction, radioresistance and speciation of bacteria in changing conditions of low variable natural and anthropogenic γ-background. CONCLUSION: We assume that γ-rays from rocks activate cellular epigenetic mechanisms that regulate genome expression, signaling and, ultimately, variability of bacteria. Some of them have already been studied, others require research.


Assuntos
Bactérias , Raios gama , Bactérias/efeitos da radiação , Bactérias/genética , Adaptação Fisiológica , Radiação de Fundo , Tolerância a Radiação , Especiação Genética
5.
Radiat Res ; 202(4): 617-625, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39134062

RESUMO

Natural background ionizing radiation is present on the earth's surface; however, the biological role of this chronic low-dose-rate exposure remains unknown. The Researching the Effects of the Presence and Absence of Ionizing Radiation (REPAIR) project is examining the impacts of sub-natural background radiation exposure through experiments conducted 2 km underground in SNOLAB. The rock overburden combined with experiment-specific shielding provides a background radiation dose rate 30 times lower than on the surface. We hypothesize that natural background radiation is essential for life and maintains genomic stability and that prolonged exposure to sub-background environments will be detrimental to biological systems. To evaluate this, human hybrid CGL1 cells were continuously cultured in SNOLAB and our surface control laboratory for 16 weeks. Cells were assayed every 4 weeks for growth rate, alkaline phosphatase (ALP) activity (a marker of cellular transformation in the CGL1 system), and the expression of genes related to DNA damage and cell cycle regulation. A subset of cells was also exposed to a challenge radiation dose (0.1 to 8 Gy of X rays) and assayed for clonogenic survival and DNA double-strand break induction to examine if prolonged sub-background exposure alters the cellular response to high-dose irradiation. At each 4-week time point, sub-background radiation exposure did not significantly alter cell growth rates, survival, DNA damage, or gene expression. However, cells cultured in SNOLAB showed significantly higher ALP activity, a marker of carcinogenesis in these cells, which increased with longer exposure to the sub-background environment, indicative of neoplastic progression. Overall, these data suggest that sub-background radiation exposure does not impact growth, survival, or DNA damage in CGL1 cells but may lead to increased rates of neoplastic transformation, highlighting a potentially important role for natural background radiation in maintaining normal cellular function and genomic stability.


Assuntos
Radiação de Fundo , Instabilidade Genômica , Humanos , Instabilidade Genômica/efeitos da radiação , Radiação de Fundo/efeitos adversos , Linhagem Celular , Dano ao DNA , Relação Dose-Resposta à Radiação , Proliferação de Células/efeitos da radiação , Fosfatase Alcalina/metabolismo , Fosfatase Alcalina/genética
6.
Isotopes Environ Health Stud ; 60(4): 417-427, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39192383

RESUMO

An important method for measuring radionuclide activity is alpha spectrometry. Ten soil samples were collected from the studied area. The activity concentrations of 238U and 234U in the collected soil samples ranged between 135 and 218 Bq kg-1 and between 117 and 183 Bq kg-1, respectively. 232Th, 230Th and 228Th activity concentrations ranged between 101 and 339, between 122 and 234 and between 106 and 385 Bq kg-1, respectively. When calculating the amount of radionuclide transport across the food chain, assessment models usually employ a transfer factor. Through root uptake, U and Th are transferred from the soil to food plants. To monitor the movement of radionuclides from the uranium series in diverse environments, it may be possible to use the ratios of uranium and thorium isotopes. Uranium mobility in soil depends on different physicochemical, organic and enzymatic factors and mechanisms. The high mobility of uranium is the main reason for the accumulation of uranium in the soil at root level and the possibility of its transfer to plants. A group of plants were selected that are grown in this area and the population relies on them mainly to meet their food needs. The concentration and transfer factor values of uranium isotopes were the highest in roots as compared with leaves and stems. Uranium in plants accumulates in roots and is then transferred to leaves. The mobility of uranium in plant tissues is constrained because it frequently adsorbs cell wall components. As a result, concentrations are frequently higher in tissues located in lower parts of the plant, with root surfaces having the highest concentrations.


Assuntos
Radiação de Fundo , Monitoramento de Radiação , Poluentes Radioativos do Solo , Tório , Urânio , Urânio/análise , Tório/análise , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Adsorção , Plantas/química , Plantas/metabolismo , Solo/química , Raízes de Plantas/química , Raízes de Plantas/metabolismo
7.
Chemosphere ; 364: 143201, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39214408

RESUMO

The activity of natural radionuclides is unevenly distributed across the Earth's crust, with certain areas exhibiting significantly higher levels than others, known as High Background Radiation Areas (HBRAs). This study presents a statistical analysis of reported activity values for coastal sands globally. Through this statistical analysis, costal sands were classified into four categories based on their activity levels, providing a standardized framework to compare the natural radioactivity of these sands. This classification is a valuable tool for identifying populations exposed to different radiation levels, which is essential for the study of stochastic effects. The study proposes thresholds to define HBRAs as regions with activity values exceeding 203 Bq/kg for 238U, 517 Bq/kg for 232Th, or 960 Bq/kg for 40K. Regions with lower values are classified as NonHBRAs. Further subdivision of these categories resulted in four distinct regions: NonHBRA-, NonHBRA+, HBRA-, and HBRA+. The activity values for these subdivisions are 92 Bq/kg and 2,903 Bq/kg for 238U, 94 Bq/kg and 7,230 Bq/kg for 232Th, and 901 Bq/kg and 2,298 Bq/kg for 40K. By calculating the external dose rates from the reported activity data, a threshold of 357 nGy/h was identified as the dose boundary separating NonHBRAs from HBRAs. The values for the subdivisions resulted 101 nGy/h and 3,867 nGy/h. The study also explores the content of these natural radionuclides in relation to their bearing minerals and discusses correlations between the reported activity values and the characteristics of the sands. Additionally, the activity of the anthropogenic radionuclide 137Cs (reported values ranging from the detection limit to 63 Bq/kg) is examined.


Assuntos
Radiação de Fundo , Monitoramento de Radiação , Tório , Urânio , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Areia , Poluentes Radioativos do Solo/análise , Tório/análise , Urânio/análise
8.
Environ Monit Assess ; 196(9): 847, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39190160

RESUMO

This investigation quantifies the activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) in the soils and certain rocks of the Koytash-Ugam Range, Uzbekistan, and assesses their radiological risks. Gamma-spectrometric analysis of soil and rock samples revealed activity concentrations ranging from 456.2 ± 56.0 to 813.9 ± 76.0 Bq kg-1 for 40K, 18.2 ± 6.3 to 70.0 ± 12.0 Bq kg-1 for 226Ra, and 30.1 ± 2.9 to 57.9 ± 10 Bq kg-1 for 232Th. This data indicates a heterogeneous distribution of radionuclides, informing radiation safety and health risk assessments on a global scale. The calculation of radiological hazard indices, including the alpha-index (ranging from 0.09 to 0.35), gamma-index (ranging from 0.40 to 0.73), and both internal (ranging from 0.40 to 0.54) and external (ranging from 0.36 to 0.54) hazard indices, was undertaken to ascertain potential health risks. The radium equivalent activity ranged from 108.4 to 199.3 Bq kg-1, and the absorbed dose rates were 51.0-93.3 nGy h-1 indoors and 96.6-178.2 nGy h-1 outdoors. These metrics underlie the estimated annual effective dose of 536.5-988.5 × 10-3 mSv y-1, highlighting the variability in radiation exposure. Additionally, the potential lifetime cancer risk was projected at 1770.4 to 3262.0 per million, with an annual gonadal dose equivalent of 361.9 to 655.5 µSv y-1, reflecting natural background radiation influence. The results underscore the importance of safe material use in construction and the necessity for routine natural radioactivity monitoring. Radon flux density (RFD) values within acceptable construction limits (26-176 mBq m-2 s-1) suggest the area's suitability for development, considering recommended safety guidelines. This study not only aids local environmental and public health frameworks but also enriches the international knowledge base, facilitating comparative studies for the advancement of global radiation protection standards. Through a detailed examination of radionuclide distribution in an under-researched area, our research highlights the critical need for integrated international approaches to natural radiological hazard assessment.


Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Tório , Poluentes Radioativos do Solo/análise , Uzbequistão , Rádio (Elemento)/análise , Tório/análise , Solo/química , Medição de Risco , Radioisótopos de Potássio/análise , Radiação de Fundo
9.
Radiat Prot Dosimetry ; 200(11-12): 1064-1069, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016484

RESUMO

The present study is carried out in 42 sampling sites for the measurement of background gamma dose rate in six tehsils of the Bageshwar district that comes under the Kumaun Himalaya, Uttarakhand. The annual effective dose in the pre-monsoon and post-monsoon seasons was estimated from the measured values of the Gamma dose rate. It is found that the minimum and maximum values ranged between 0.01-0.39 mSv per y (Arithmetic Mean = 0.19 mSv per y) in the pre-monsoon and 0.11-0.42 mSv per y (Arithmetic Mean = 0.20 mSv per y) in the post-monsoon season of the year. The finding of the present study shows that the annual effective dose equivalent is higher than the worldwide average value recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation.


Assuntos
Raios gama , Doses de Radiação , Monitoramento de Radiação , Estações do Ano , Poluentes Radioativos do Solo , Índia , Monitoramento de Radiação/métodos , Humanos , Poluentes Radioativos do Solo/análise , Radiação de Fundo
10.
Radiat Prot Dosimetry ; 200(11-12): 1114-1120, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016492

RESUMO

Studies on ambient gamma radiation in indoor and outdoor environment and their effect on human health have created interest among the researchers across the world. The present study represents the results of indoor and outdoor ambient gamma dose rates around the Kaveri river basin from Talakaveri (Madikeri district) to Mekedatu (Ramanagara district) by using portable Environmental Radiation Dosemeter. The annual effective dose in the present study area varies between 0.14 mSv.y-1 and 0.58 mSv.y-1 with an average value of 0.30 mSv.y-1 for indoor radiation. The outdoor annual effective dose ranged between 0.01 mSv.y-1 and 0.14 mSv.y-1 with an average value of 0.06 mSv.y-1. The total annual effective dose varies from 0.17 to 0.72 mSv.y-1 with an average value of 0.36 mSv.y-1. The calculated values of indoor and outdoor annual effective dose in the study area (are found to be lower than the world average values (1 mSv.y-1 and 0.48 mSv.y-1).


Assuntos
Raios gama , Doses de Radiação , Monitoramento de Radiação , Rios , Índia , Monitoramento de Radiação/métodos , Rios/química , Humanos , Poluição do Ar em Ambientes Fechados/análise , Poluentes Radioativos do Ar/análise , Radiação de Fundo
11.
Radiat Prot Dosimetry ; 200(11-12): 1041-1046, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016506

RESUMO

Radionuclide activity of the selected radionuclides 238U, 232Th and 40K was measured in surface soil samples collected from 40 villages of the western part of Yadgir district of Karnataka. A 4″ × 4″ NaI (Tl) detector based on a gamma spectrometer is used for the estimation of radionuclides. The major type of soil in this region is sandy and red. The 222Rn activity concentrations in drinking water were determined by the Emanometry method. The 222Rn activity in ground water is found to vary from 1.73 to 155.6 Bql-1. The total annual effective doses because of 222Rn inhalation and ingestion range from 4.72 to 424.84 µSv y-1 with an average value of 108.8 µSv y-1, respectively. Among the sampling stations, Shahapur and Shorapur soil samples show higher activity values than the Kembhavi and Hunasagi sampling stations soil samples.


Assuntos
Água Potável , Radioisótopos de Potássio , Monitoramento de Radiação , Poluentes Radioativos do Solo , Poluentes Radioativos da Água , Índia , Poluentes Radioativos do Solo/análise , Monitoramento de Radiação/métodos , Água Potável/análise , Poluentes Radioativos da Água/análise , Radioisótopos de Potássio/análise , Tório/análise , Urânio/análise , Espectrometria gama , Humanos , Radônio/análise , Radiação de Fundo , Solo/química
12.
Radiat Prot Dosimetry ; 200(11-12): 1059-1063, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016509

RESUMO

Natural radioactivity measurement, radiation monitoring of the region, dose assessment and interpretation of radiological-related parameters are crucial aspects from the public awareness and environmental safety point of view. The ionising radiations (gamma-rays) emitted from radionuclides such as 226Ra, 232Th and 40K present in environmental materials contributes significantly to the external radiation dose received by the public. High-efficiency gamma spectrometry based on a 4″ × 4″ NaI (Tl) detector was employed for estimating activity concentrations of the gamma-emitting radioelements. The spectra from the detector were recorded using a PC-based 1k multichannel analyser system (WinTMCA 32). Each sample spectrum was acquired for a counting period of 60 000 s (16.67 hr). Assuming the daughter products of 226Ra and 232Th in equilibrium, the activity concentration of these radionuclides were estimated by using the prominent gamma photo peaks of daughter products. Using the same technique, dose-related radiological parameters were calculated for all the samples. The activity concentrations of the radionuclides and the dose-related parameters for the samples were found to be comparable with the global literature values. The data generated from our study will contribute to the baseline radiological data of the region.


Assuntos
Radiação de Fundo , Raios gama , Radioisótopos de Potássio , Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Espectrometria gama , Tório , Índia , Monitoramento de Radiação/métodos , Poluentes Radioativos do Solo/análise , Tório/análise , Radioisótopos de Potássio/análise , Rádio (Elemento)/análise , Doses de Radiação
13.
Radiat Prot Dosimetry ; 200(11-12): 1070-1075, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016513

RESUMO

The natural radioactivity concentration was studied for 40 soil samples of the Churchandpur and Ukhrul districts of Manipur, India, by using gamma-ray spectroscopy. The average radioactivity concentration of 226Ra, 232Th and 40K in Churchandpur was found as 39.9 (range: 30-56), 72.1 (range: 57-93) and 564.1 (range:360-867) Bq kg-1 respectively, whereas, in Ukhrul, average radioactivity for the same was found as 30.3 (range: 16-54), 54.2 (range:24-89) and 637.1(range:103-901) Bq kg-1, respectively. The calculated radioactivity parameters were compared with the world average values. The measured radium equivalent activity (Raeq), absorbed dose rate ($\dot{\mathrm D}$), annual effective outdoor dose(E) and the external hazard index (Hex) were observed as 165 (range: 63.7-234.8) Bq kg-1, 77.6 (36.9-108.0) nGy h-1, 0.11 (0.05-0.13) mSv y-1 and 0.5 (0.1-0.6), respectively. This study aims to provide baseline data for radionuclide present in the Churchandpur and Ukhrul districts of Manipur.


Assuntos
Radiação de Fundo , Radioisótopos de Potássio , Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Tório , Poluentes Radioativos do Solo/análise , Índia , Monitoramento de Radiação/métodos , Tório/análise , Rádio (Elemento)/análise , Radioisótopos de Potássio/análise , Doses de Radiação , Espectrometria gama , Solo/química
14.
Appl Radiat Isot ; 211: 111424, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38970986

RESUMO

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 ß-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 ß-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.


Assuntos
Estresse Oxidativo , Animais , Masculino , Ratos , Estresse Oxidativo/efeitos da radiação , Radiação de Fundo , Neurotransmissores/metabolismo , Neurotransmissores/sangue , Encéfalo/efeitos da radiação , Encéfalo/metabolismo , Peroxidação de Lipídeos/efeitos da radiação , Peptídeos beta-Amiloides/metabolismo
15.
Environ Sci Pollut Res Int ; 31(30): 43292-43308, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38902441

RESUMO

Labuan, Miri, Kundasang and Raub regions of Malaysia have very different geological formations and settings that could result in different levels of natural radioactivity. Hence, this study determines the influence of different geological formations on radioactivity in these locations using field measurements, petrology and geochemistry. A total of 141 gamma dose rates and 227 beta flux measurements were collected using Polimaster survey meters (PM1405) in these four regions. The gamma dose rate values range from 0.37 to 0.05 µSv/h with a mean value of 0.11 µSv/h. Beta flux values range from 3.46 to 0.12 CPS with a mean value of 0.57 CPS. Mineralogy and elemental composition of the different rock types were analysed using thin-section petrography, XRD, ICP and pXRF methods. Felsic igneous rocks such as syenite and granite have higher natural radioactivity and contain more radionuclide-bearing minerals such as apatite, zircon, allanite, K-feldspar, titanite, muscovite and biotite. Metamorphic rocks have the second highest natural radioactivity and contain fewer radioactive minerals. The natural radioactivity of sedimentary rocks mostly depends on their clay content. The gamma dose rate maps show that igneous and metamorphic regions around Raub have higher radioactivity compared to the sedimentary-dominated regions around Miri and Labuan. Annual effective dose (AED) and excess lifetime cancer risk (ELCR) were calculated to evaluate the potential health risk for inhabitants of these regions. Labuan and Miri are considered to be safe zones with respect to natural radioactivity as the results show little to no risk for the public, compared with the Raub region, which is medium to high risk.


Assuntos
Monitoramento de Radiação , Radioatividade , Malásia , Medição de Risco , Geologia , Radiação de Fundo
16.
Radiat Prot Dosimetry ; 200(10): 881-889, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38834189

RESUMO

This research forms a part of the comprehensive Indian Environmental Radiation Monitoring Network program, focusing on the continuous measurement of absorbed dose rate in outdoor air due to natural gamma radiation (cosmic and terrestrial) in Bengaluru, Karnataka, India. Over the course of a decade (2013-2023), data were collected from 41 monitoring locations in the city using permanently field-installed Geiger-Mueller detector-based environmental radiation monitors. This paper presents an analysis of the extensive long-term monitoring results. The mean absorbed gamma dose rate in outdoor air across the monitoring locations ranged from 84 ± 9 to 156 ± 4 nGy.h-1, with a calculated mean value of 124 ± 15 nGy.h-1. The estimated mean annual effective dose due to outdoor natural gamma radiation varied from 0.10 ± 0.01 to 0.19 ± 0.01 mSv.y-1, with an overall mean of 0.15 ± 0.02 mSv.y-1.


Assuntos
Poluentes Radioativos do Ar , Radiação de Fundo , Raios gama , Doses de Radiação , Monitoramento de Radiação , Índia , Monitoramento de Radiação/métodos , Poluentes Radioativos do Ar/análise , Humanos
17.
Radiat Prot Dosimetry ; 200(10): 938-944, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38855821

RESUMO

An assessment of radioactivity concentration of reinforced cement concrete types of house was conducted in the valley region of Manipur, India. The average radioactivity concentration of 226Ra, 232Th, and 40K of portland cements are 39 (range: 32-52) Bqkg-1, 36 (range: 22-62) Bqkg-1, and 1812 (1254-2424) Bqkg-1; for concrete are 36 (range: 26-45) Bqkg-1, 65 (range: 45-86) Bqkg-1, and 660 (639-681) Bqkg-1; for sand are 45 (30-61) Bqkg-1, 114 (range: 55-212) Bqkg-1, and 1859 (range: 1413-2232) Bqkg-1; and for bricks are 30 (range: 24-37) Bqkg-1, 148 (range:79-184) Bqkg-1, and 1444 (range: 1093-2103) Bqkg-1, respectively. The annual effective dose was observed with an average value of 1.9 (range: 0.9-3.3) mSvy-1. However, gamma index was observed with an average value of 1.1 (range: 0.5-2.0).


Assuntos
Materiais de Construção , Radioisótopos de Potássio , Monitoramento de Radiação , Rádio (Elemento) , Tório , Materiais de Construção/análise , Índia , Monitoramento de Radiação/métodos , Tório/análise , Rádio (Elemento)/análise , Radioisótopos de Potássio/análise , Radiação de Fundo , Humanos , Doses de Radiação
18.
PLoS One ; 19(6): e0304810, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38857267

RESUMO

This paper reports the results of gamma irradiation experiments and whole genome sequencing (WGS) performed on vegetative cells of two radiation resistant bacterial strains, Metabacillus halosaccharovorans (VITHBRA001) and Bacillus paralicheniformis (VITHBRA024) (D10 values 2.32 kGy and 1.42 kGy, respectively), inhabiting the top-ranking high background radiation area (HBRA) of Chavara-Neendakara placer deposit (Kerala, India). The present investigation has been carried out in the context that information on strategies of bacteria having mid-range resistance for gamma radiation is inadequate. WGS, annotation, COG and KEGG analyses and manual curation of genes helped us address the possible pathways involved in the major domains of radiation resistance, involving recombination repair, base excision repair, nucleotide excision repair and mismatch repair, and the antioxidant genes, which the candidate could activate to survive under ionizing radiation. Additionally, with the help of these data, we could compare the candidate strains with that of the extremely radiation resistant model bacterium Deinococccus radiodurans, so as to find the commonalities existing in their strategies of resistance on the one hand, and also the rationale behind the difference in D10, on the other. Genomic analysis of VITHBRA001 and VITHBRA024 has further helped us ascertain the difference in capability of radiation resistance between the two strains. Significantly, the genes such as uvsE (NER), frnE (protein protection), ppk1 and ppx (non-enzymatic metabolite production) and those for carotenoid biosynthesis, are endogenous to VITHBRA001, but absent in VITHBRA024, which could explain the former's better radiation resistance. Further, this is the first-time study performed on any bacterial population inhabiting an HBRA. This study also brings forward the two species whose radiation resistance has not been reported thus far, and add to the knowledge on radiation resistant capabilities of the phylum Firmicutes which are abundantly observed in extreme environment.


Assuntos
Raios gama , Genoma Bacteriano , Tolerância a Radiação , Tolerância a Radiação/genética , Radiação de Fundo , Sequenciamento Completo do Genoma , Índia , Bacillus/genética , Bacillus/efeitos da radiação , Bacillus/metabolismo , Reparo do DNA
19.
J Environ Radioact ; 276: 107447, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38749216

RESUMO

Soil is an important source and medium of radionuclides, and the content of radioactivity in soil is crucial for radiological impact evaluation. In this study, twenty soil samples in the high background natural radiation area of Yangjiang, China were collected and analyzed for 226Ra, 232Th, 40K and 137Cs concentrations in order to evaluate the radiological health risk in the area. Results showed that the average activity concentrations of 226Ra, 232Th and 40K are 66 Bq/kg, 109 Bq/kg and 211 Bq/kg, respectively. The calculated radiological parameters of radium equivalent activity (Raeq), absorbed dose rate (D), annual effective dose equivalent (AEDE), internal and external hazard indices (Hin and Hex) show a large variation at different sampling sites. Additionally, the elemental oxidation composition and 40K/K mass ratio in the soil were analyzed to further augment the background information of the high background radiation area in Yangjiang.


Assuntos
Radiação de Fundo , Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Solo , Tório , Poluentes Radioativos do Solo/análise , China , Solo/química , Rádio (Elemento)/análise , Tório/análise , Radioisótopos de Potássio/análise , Radioisótopos de Césio/análise , Oxirredução
20.
Environ Geochem Health ; 46(6): 181, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695964

RESUMO

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayasi regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayasi. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg-1 for 232Th, 4.21 to 13.41 Bq kg-1 for 40K, and 0.42-3.26 Bq kg-1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).


Assuntos
Radioisótopos de Césio , Radioisótopos de Potássio , Monitoramento de Radiação , Turquia , Monitoramento de Radiação/métodos , Radioisótopos de Potássio/análise , Radioisótopos de Césio/análise , Tório/análise , Poluentes Radioativos do Solo/análise , Radiação de Fundo , Humanos , Medição de Risco
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