1
|
Khasanov S, Safarov A, Tukhtaev U, Mavlonov T. A short overview of radioactivity measurement studies in Uzbekistan. REVIEWS ON ENVIRONMENTAL HEALTH 2024; 39:101-110. [PMID: 36181732 DOI: 10.1515/reveh-2022-0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
Natural radioactivity is a public health issue that affects people all around the world. Environmental radioactivity accounts for approximately 87% of the radiation dose received by human beings. The primary external source of irradiation to the human body is gamma radiation emitted by naturally occurring radioisotopes such as 40K and radionuclides from the 232Th and 238U families, as well as their decay products, which exist at trace amounts in all ground formations. The establishment of baseline data for environmental radiological studies is of great importance for the assessment of environmental radiological levels in Uzbekistan and related studies on human health risks. The current study aimed to describe the research state of the art on natural radioactivity in Uzbekistan with emphasis on results obtained during the last 20 years. NaI (Tl) and High Purity Germanium HPGe detectors were employed in most conducted studies. The results showed that data for natural radionuclide activity were below international standards in all but a few areas. The research results of this paper can play a good guidance and reference role in the planning of such research in the future.
Collapse
Affiliation(s)
- Shakhboz Khasanov
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Samarkand State University, Samarkand, Uzbekistan
| | | | | | | |
Collapse
|
2
|
Upadhyay DR, Koirala G, Shah BR, Tajudin SM, Khanal R. Assessing radioactive contaminants in Kathmandu soils: measurement and risk analysis. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:190. [PMID: 38261087 DOI: 10.1007/s10661-023-12284-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024]
Abstract
Soil samples from vegetable farmland in densely populated wards of Nepal were analyzed for natural radionuclide levels, employing a NaI(Tl) 3" [Formula: see text] 3" gamma detector. The study aimed to evaluate the causes of radiation risk, attributing it to soil contamination resulting from the rapid urbanization and concretization that followed the earthquake in 2015. The activity concentration of radium-226, thorium-232, and potassium-40 and the ranges observed are 2.080±0.084-33.675±1.356 Bq kg[Formula: see text], 17.222±0.198-119.949±1.379 Bq kg[Formula: see text], and 11.203 ± 0.325-748.828±21.716 Bq kg[Formula: see text], respectively. The average values obtained for hazard indices are as follows: radium equivalent activity (82.779 Bq kg[Formula: see text]), absorbed dose rate (36.394 nGy h[Formula: see text]), annual effective dose equivalent (0.045 mSv yearr[Formula: see text]), gamma index (0.291), external hazard index (0.224), internal hazard index (0.253), excess lifetime cancer risk (0.159), annual gonadal dose equivalent (243.278 mSv year[Formula: see text]), alpha index (0.054), and activity utilization index (0.716). However, in most places, thorium-232 concentration is greater than those of the world average and recommended values. In specific locations such as Ward 4 in Baluwatar, the soil was found to have concentrations of Ra[Formula: see text] and K[Formula: see text] exceeding recommended limits. Despite this localized concern, the overall analysis of hazard indices across the studied areas revealed that most values were within permissible limits. This suggests that, on a broader scale, radiation exposure may not be a significant concern in the investigated regions. Nonetheless, the study recommends regular monitoring in additional locations to ensure a comprehensive and ongoing assessment of radiation levels.
Collapse
Affiliation(s)
- Devendra Raj Upadhyay
- Central Department of Physics, Tribhuvan University, Kathmandu, 44600, Bagmati, Nepal.
- Department of Physics, Amrit Campus, Tribhuvan University, Kathmandu, 44600, Bagmati, Nepal.
| | - Gaurab Koirala
- Department of Physics, Amrit Campus, Tribhuvan University, Kathmandu, 44600, Bagmati, Nepal
| | - Buddha Ram Shah
- Nepal Academy of Science and Technology, Lalitpur, 3323, Bagmati, Nepal
| | - Suffian Mohamad Tajudin
- Faculty of Health Sciences, Sultan Zainal Abidin University, 21300, Terengganu, Kuala Terengganu, Malaysia
| | - Raju Khanal
- Central Department of Physics, Tribhuvan University, Kathmandu, 44600, Bagmati, Nepal
| |
Collapse
|
3
|
do Nascimento-Silva C, do Carmo-Neto EF, de Santana SL, de Amorim EM, de Oliveira RA, de Amaral DS, Costa MAR, do Nascimento AF, Dos Santos RA, De França EJ, Rohde C. Accessing the Health Risk of Ingestion of Surface Water from Lucrécia and Parelhas Dams in Northeast Brazil Using the Sentinel Organism Drosophila melanogaster. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2023; 112:12. [PMID: 38093100 DOI: 10.1007/s00128-023-03838-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023]
Abstract
This study investigated the genotoxic risk of chronic exposure of hemolymph's cells of Drosophila melanogaster (Insecta, Diptera) to water samples from Boqueirão de Parelhas Dam and from Lucrécia Dam in the semiarid region of Brazil. The dams are located over the Pegmatite Province of Borborema, with rocks rich in uranium and thorium. Water samples hydrated a culture medium composed of mashed potatoes, where larvae of D. melanogaster fed for 24 h, before be underwent to the Comet assay. The same water was evaluated for the presence of dissolved Radon gas (222Rn) and concentrations of 11 toxic metals (Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). The results indicated a genotoxic effect resulting from exposure to the waters of the Parelhas dam, in the samples of August 2018; and in Lucrécia dam, in January 2019. D. melanogaster stood out for its high sensitivity to monitor the genotoxic effects of compounds dissolved in public dams. And unlike to other essentially aquatic sentinel organisms, this species stood out as a model to concomitant studies of air and water possible contaminated, in a scenario of natural environmental radioactivity present in semiarid of Brazil.
Collapse
Affiliation(s)
- Charles do Nascimento-Silva
- Programa de Pós-Graduação em Biologia Animal, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, CEP 50670-901, Recife, Pernambuco, Brazil
- Laboratório de Genética, Centro Acadêmico de Vitória (CAV), Universidade Federal de Pernambuco (UFPE), Rua do Alto do Reservatório s/n, CEP 55608-680, Vitória de Santo Antão, Pernambuco, Brazil
| | - Edson Francisco do Carmo-Neto
- Laboratório de Genética, Centro Acadêmico de Vitória (CAV), Universidade Federal de Pernambuco (UFPE), Rua do Alto do Reservatório s/n, CEP 55608-680, Vitória de Santo Antão, Pernambuco, Brazil
| | - Samuel Lima de Santana
- Laboratório de Genética, Centro Acadêmico de Vitória (CAV), Universidade Federal de Pernambuco (UFPE), Rua do Alto do Reservatório s/n, CEP 55608-680, Vitória de Santo Antão, Pernambuco, Brazil
| | - Erima Maria de Amorim
- Laboratório de Genética, Centro Acadêmico de Vitória (CAV), Universidade Federal de Pernambuco (UFPE), Rua do Alto do Reservatório s/n, CEP 55608-680, Vitória de Santo Antão, Pernambuco, Brazil
| | - Rafaela Alves de Oliveira
- Laboratório de Genética, Centro Acadêmico de Vitória (CAV), Universidade Federal de Pernambuco (UFPE), Rua do Alto do Reservatório s/n, CEP 55608-680, Vitória de Santo Antão, Pernambuco, Brazil
| | - Deric Soares de Amaral
- Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), Comissão Nacional de Energia Nuclear, Avenida Professor Luiz Freire 200, CEP 50740-545, Recife, Pernambuco, Brazil
| | - Matheus Andrade Rocha Costa
- Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), Comissão Nacional de Energia Nuclear, Avenida Professor Luiz Freire 200, CEP 50740-545, Recife, Pernambuco, Brazil
| | - Alesxandro Francisco do Nascimento
- Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), Comissão Nacional de Energia Nuclear, Avenida Professor Luiz Freire 200, CEP 50740-545, Recife, Pernambuco, Brazil
| | - Robson Alves Dos Santos
- Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), Comissão Nacional de Energia Nuclear, Avenida Professor Luiz Freire 200, CEP 50740-545, Recife, Pernambuco, Brazil
| | - Elvis Joacir De França
- Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE), Comissão Nacional de Energia Nuclear, Avenida Professor Luiz Freire 200, CEP 50740-545, Recife, Pernambuco, Brazil
| | - Claudia Rohde
- Programa de Pós-Graduação em Biologia Animal, Universidade Federal de Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, CEP 50670-901, Recife, Pernambuco, Brazil.
- Laboratório de Genética, Centro Acadêmico de Vitória (CAV), Universidade Federal de Pernambuco (UFPE), Rua do Alto do Reservatório s/n, CEP 55608-680, Vitória de Santo Antão, Pernambuco, Brazil.
| |
Collapse
|
4
|
Martinelli S, Medeiros AN, de Souza RF, Marconi AM, Navoni JA. Analysis of the cancer occurrence related to natural radioactivity in the Rio Grande do Norte State, Brazil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:89140-89152. [PMID: 37442937 DOI: 10.1007/s11356-023-28708-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023]
Abstract
The state of Rio Grande do Norte, located in the Northeast region of Brazil, has areas of granites and pegmatites with minerals that have varying concentrations of uranium. Consequently, high concentrations of radon gas, a carcinogenic substance for humans, can occur. The present study aimed to assess the occurrence of cancer and its association with exposure to sources of natural radioactivity using geological and geophysical information in the aforementioned state. The spatial dependence of pulmonary, breast, stomach, leukemia, and skin cancer cases with the location of radioisotope sources were analyzed using geoprocessing tools. The geoprocessing analysis showed a differential pattern of uranium emission throughout the state, with the highest emission from areas with pegmatites outcrops. A spatial dependency of cancer cases was shown (Moran index: 0.43; p < 0.01). Moreover, a higher rate of natural radioactivity-cancer cases was associated with the high-intensity natural radioactivity areas: odds ratio:1.21 (95% CI 1.20; 1.23), following the same pattern when separately compared the different related types of cancer. These results highlight the importance of natural radioactivity as a public health problem in the Brazilian environmental scenario, confirming the need for further studies as the first toward understanding and implementing health management strategies mitigating the exposures, especially in areas of environmental risk.
Collapse
Affiliation(s)
- Simone Martinelli
- Development and Environment, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | - Amanda Nogueira Medeiros
- Development and Environment, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | - Raquel Franco de Souza
- Development and Environment, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
- Center for Exact and Earth Sciences - Department of Geology, Laboratory of Geochemistry, Federal University of Rio Grande Do Norte, Natal, RN, Brazil
| | | | - Julio Alejandro Navoni
- Development and Environment, Biosciences Center, Federal University of Rio Grande Do Norte, Avenida Sen. Salgado Filho, No. 3000, Lagoa Nova, Natal, RN, 59078-970, Brazil.
| |
Collapse
|
5
|
Njinga RL, Ogundele TL, Adebayo AS, Olatunji MA, Olufemi AP, Olowookere CJ, Aladeniyi K, Pereira A, Arogunjo MA, Tshivhase VM. Distribution dynamics and descriptive statistical analysis of radionuclides in the farmland soils near mining areas in Southwestern Nigeria. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:3617-3636. [PMID: 36456669 DOI: 10.1007/s10653-022-01440-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/18/2022] [Indexed: 06/01/2023]
Abstract
Human exposure to ionizing radiation in the environment is mainly due to naturally occurring radionuclides in the soils, building materials and rocks, but the level may vary depending on the anthropogenic activities prevalent in each location. Presently, in Nigeria, there are concerns due to environmental health implications of all sorts of mineral mining and processing spreading across the southwestern states of the country. This work determines the activity concentrations of naturally occurring radionuclide materials (NORMs) in the farmland soil with the aim of evaluating the radiation hazards. A total of 200 composite soil samples were taken from five states in the southwest of Nigeria, close to active mining sites at the root (0.2 m) and at deep planting zones (0.5 m) for analysis by gamma-ray spectrometry using NaI(Tl) detector. The activity concentrations of natural radionuclides in the composite soil samples were determined to vary in the order of 40 K > 232Th > 226Ra/238U for all locations. In contrast to the other locations, Olode and Igbokoda had average radium equivalent activities (Raeq) to be 1.6 and 1.8 times, respectively, higher than the reference limit of 370 Bqkg-1. The estimated excess life cancer risk values were lower than the 0.29 × 10-3 global average value for soil by United Nations on Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and International Commission on Radiological Protection (ICRP). Negative and low skewness values of 0.61 and 1.20 were obtained for 40 K in Itagunmodi, and also 0.47 and 0.66 for 232Th were obtained in Sagamu. The kurtosis analysis of the activity concentrations was low and negative for soil at Itagunmodi for 40 K and 226Ra/238U; Olode for 40 K and 232Th; and Igbokoda for 226Ra/238U and 232Th where mining activities are commonly practiced. The variation in the results has been attributed to different agriculture practices and artisanal mining operations in each location.
Collapse
Affiliation(s)
- Raymond L Njinga
- Department of Physics, University of Medical Sciences, Ondo, Nigeria.
| | - Tunde L Ogundele
- Department of Physics, University of Medical Sciences, Ondo, Nigeria
| | - Adebiyi S Adebayo
- Department of Physics, University of Medical Sciences, Ondo, Nigeria
| | | | - Ayodele P Olufemi
- Department of Physics, University of Medical Sciences, Ondo, Nigeria
| | | | - Kehinde Aladeniyi
- Department of Physics, Federal University of Technology, Akure, Ondo, Nigeria
| | - Alcides Pereira
- Department of Earth Sciences, University of Coimbra, Coimbra, Portugal
| | - Muyiwa A Arogunjo
- Department of Physics, Federal University of Technology, Akure, Ondo, Nigeria
| | - Victor M Tshivhase
- Department of Physics, University of Johannesburg, Johannesburg, South Africa
| |
Collapse
|
6
|
Circ-CPSF1 Worsens Radiation-Induced Oxidative Stress Injury in Caenorhabditis elegans. Biomolecules 2023; 13:biom13010102. [PMID: 36671487 PMCID: PMC9856148 DOI: 10.3390/biom13010102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/06/2022] [Accepted: 12/27/2022] [Indexed: 01/06/2023] Open
Abstract
Radioactive substances have been used in various aspects in daily life. However, high-energy radiation could cause environmental problems, which would damage the human body. Circular RNA (CircRNA) has great potential in the minimization of ionizing radiation damage. To find a potential diagnostic and therapeutic target for reducing the damage of ionizing radiation, we selected circRNA cleavage and polyadenylation specificity factor subunit 1 (circ-CPSF1) based on its up-regulated expression after X-ray radiation and explored its effect on response to ionizing radiation using Caenorhabditis elegans (C. elegans). Circ-CPSF1 was screened out and its up-regulated expression was verified. The measurement of lifespan and germ cell apoptosis showed that circ-CPSF1 RNAi treatment extended lifespan and reduced apoptotic germ cells. ROS levels were significantly reduced after the interference of circ-CPSF1 in C. elegans with radiation. Mitochondrial membrane potential assay showed that the suppression of circ-CPSF1 could alleviate mitochondrial damage after radiation. Relative genes expression showed the involvement of circ-CPSF1 in radiation mediated DNA damage response pathways and apoptosis pathways. In conclusion, circ-CPSF1 exerts deleterious effects on lifespan, eggs production and germ cell apoptosis of C. elegans through oxidative stress, the DNA damage response (DDR) pathway, and the core apoptotic pathway after ionizing radiation, indicating the potential of circ-CPSF1 to be an important therapeutic target of radiation damage.
Collapse
|
7
|
Dos Santos Junior OP, Dos Santos Junior JA, Moraes AS, Amaral RDS, Simões Menezes RC, Jose Isidoro de Araújo Rodrigues Azevedo A. Anthropogenic accumulation based on chemometrics of the radionuclide K-40 in tropical soils in the northeast Brazil. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 251-252:106981. [PMID: 36007394 DOI: 10.1016/j.jenvrad.2022.106981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 07/21/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
The continuous use of fertilizers can increase the radionuclides levels in soils, and their accumulation and concentration are related to their characteristics and the various processes of use and soil occupation. Analyzing data from radiometric and pedological measurements often demands the use of more robust tools for better integration of results. This work presents the results of a study to evaluate the accumulation of 40K, in an area of the Zona da Mata region in Pernambuco, Northeastern Brazil, due to the contribution of natural or artificial sources. 40K activity concentration was measured by high resolution gamma spectrometry in 108 soil samples, as well the organic matter content and particle size distribution. Results showed the 40K activity ranged from 103 to 1843 Bq.Kg-1, with the arable soils showing levels above the world average value (420 Bq.Kg-1). A higher prevalence of 40K was observed on arable soils, regardless of soil type, organic matter content, depth or texture. Agricultural activities increased of 40K levels in different degrees, depending on the type of crop used, with an accumulation factor of up to 4 times greater compared to soils not impacted by agricultural activities. The radiochemometric diagnosis maded it possible to draw up a strategic management plan to improve the management practices of family farming in order to maximize production efficiency, and promote the conservation of natural resources and environmental preservation.
Collapse
|
8
|
Paul SN, Frazzoli C, Sikoki FD, Babatunde BB, Orisakwe OE. Natural occurring radioactive materials (NORMs) from mining sites in Nigeria: A systematic review of geographical distribution and public health concern. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 249:106889. [PMID: 35525078 DOI: 10.1016/j.jenvrad.2022.106889] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/10/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
Solid mineral mining activities have contributed to the distribution and uptake of radionuclides. This has increased the active concentration of naturally occurring radioactive materials NORMs in different environmental media with increased human health risks. This systematic review was aimed at assessing data on active concentration of naturally occurring radioactive materials in mining sites in Nigeria. Articles available on recognized data bases such as Google scholar, PubMed, Cochrane Library and Science Direct were used. Thirty-two studies were used for this systematic review after meeting the inclusion criteria. Reports of studies according to Geopolitical zones revealed 0% North-east, 4% for Southeast, 8% for South-South, 16% in North-West, 20% in South-West, and 52% from North-Central Nigeria. 50%, 45.2%, 50%, and 38.5% of included studies reported elevated active concentration of 232Th, 40K, 238U and 226Ra in soil above world regulatory standards of the ICRP, UNSCEAR and IAEA. Gross-alpha and gross-beta activity concentrations reference dose level (RDL) were exceeded in 83.3% and 80% of studies respectively with the highest values recorded in water 10.12Bq/l, and 14.63Bq/l from an artisanal gold mine in North-West Nigeria. These data agree with reports from other African countries, but lower than reports from China and India. NORMs may be of public health concerns notwithstanding the lean data from clinical and epidemiological studies in Nigeria. This study recommends a One Health approach on the radiological implications of mining sites in Nigeria.
Collapse
Affiliation(s)
- Samuel N Paul
- World Bank African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, PMB, Port Harcourt, Rivers State, Choba, 5323, Nigeria
| | - Chiara Frazzoli
- Department of Cardiovascular and Endocrine-Metabolic Diseases and Ageing, Istituto Superiore di Sanita, Rome, Italy
| | - Francis D Sikoki
- Department of Animal and Environmental Biology, University of Port Harcourt, PMB, Port Harcourt, Choba, 5323, Nigeria
| | - Bolaji B Babatunde
- Department of Animal and Environmental Biology, University of Port Harcourt, PMB, Port Harcourt, Choba, 5323, Nigeria
| | - Orish E Orisakwe
- World Bank African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, PMB, Port Harcourt, Rivers State, Choba, 5323, Nigeria.
| |
Collapse
|
9
|
Ghosh A. Biological and cellular responses of humans to high-level natural radiation: A clarion call for a fresh perspective on the linear no-threshold paradigm. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2022; 878:503478. [PMID: 35649671 DOI: 10.1016/j.mrgentox.2022.503478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 06/15/2023]
Abstract
There remains considerable uncertainty in obtaining risk estimates of adverse health outcomes of chronic low-dose radiation. In the absence of reliable direct data, extrapolation through the linear no-threshold (LNT) hypothesis forms the cardinal tenet of all risk assessments for low doses (≤ 100 mGy) and for the radiation protection principle of As Low As Reasonably Achievable (ALARA). However, as recent evidences demonstrate, LNT assumptions do not appropriately reflect the biology of the cell at the low-dose end of the dose-response curve. In this regard, human populations living in high-level natural radiation areas (HLNRA) of the world can provide valuable insights into the biological and cellular effects of chronic radiation to facilitate improved precision of the dose-response relationship at low doses. Here, data obtained over decades of epidemiological and radiobiological studies on HLNRA populations is summarized. These studies do not show any evidence of unfavourable health effects or adverse cellular effects that can be correlated with high-level natural radiation. Contrary to the assumptions of LNT, no excess cancer risks or untoward pregnancy outcomes have been found to be associated with cumulative radiation dose or in-utero exposures. Molecular biology-driven studies demonstrate that chronic low-dose activates several cellular defence mechanisms that help cells to sense, recover, survive, and adapt to radiation stress. These mechanisms include stress-response signaling, DNA repair, immune alterations and most importantly, the radiation-induced adaptive response. The HLNRA data is consistent with the new evolving paradigms of low-dose radiobiology and can help develop the theoretical framework of an alternate dose-response model. A rational integration of radiobiology with epidemiology data is imperative to reduce uncertainties in predicting the potential health risks of chronic low doses of radiation.
Collapse
Affiliation(s)
- Anu Ghosh
- Animal House Facility & Radiation Signaling Section, Radiation Biology & Health Sciences Division, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400 085, India; Homi Bhabha National Institute (HBNI), Anushaktinagar, Mumbai 400 094, India.
| |
Collapse
|
10
|
Silva JM, Navoni JA, Amaral VS, Freire EMX. Cytogenetic analysis of nuclear abnormalities in the erythrocytes of gecko lizards (Phyllopezus periosus) collected in a semi-arid region of northeast Brazil: Possible effects of natural background radioactivity. Mutat Res 2021; 865:503346. [PMID: 33865540 DOI: 10.1016/j.mrgentox.2021.503346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 11/29/2022]
Abstract
High natural-background radioactivity levels occur in the semi-arid region of the State of Rio Grande do Norte, northeastern Brazil. We have studied the lizard Phyllopezus periosus, an endemic species of the Brazilian caatinga with saxicolous habitat, as a bioindicator of environmental quality. Specimens were collected in three areas, an environmental protection area and two areas recognized as having high natural background radiation, one of these being a mining area. Level of metals and gamma radiation emitters present in the water sources potentially used by the lizards were measured. The biological endpoints assessed were micronuclei and nuclear abnormalities in blood samples. Significant differences in background radioactivity levels were found among the assessed areas. Statistically significant differences in micronuclei and nuclear abnormality frequencies were seen, among the study areas and a relationship between radioactivity level and genetic damage was observed.
Collapse
Affiliation(s)
- Jadna Maria Silva
- Programa de Pós-graduação em Desenvolvimento e Meio, Ambiente da Universidade Federal do Rio Grande do Norte, Brazil
| | - Júlio Alejandro Navoni
- Programa de Pós-graduação em Desenvolvimento e Meio, Ambiente da Universidade Federal do Rio Grande do Norte, Brazil; Programa de Pós-graduação em Uso Sustentável de Recursos Naturais do Instituto Federal do Rio Grande do Norte, IFRN, Brazil
| | - Viviane Souza Amaral
- Programa de Pós-graduação em Desenvolvimento e Meio, Ambiente da Universidade Federal do Rio Grande do Norte, Brazil; Departamento de Biologia Celular e Genética, UFRN, Brazil
| | - Eliza Maria Xavier Freire
- Programa de Pós-graduação em Desenvolvimento e Meio, Ambiente da Universidade Federal do Rio Grande do Norte, Brazil; Departamento de Botânica e Zoologia, UFRN, Brazil.
| |
Collapse
|
11
|
Saeed A, Murshed MN, Al-Shahari EA. Effect of low-dose fast neutrons on the protein components of peripheral blood mononuclear cells of whole-body irradiated Wistar rats. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:40443-40455. [PMID: 32666461 DOI: 10.1007/s11356-020-10085-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/09/2020] [Indexed: 06/11/2023]
Abstract
The immune system is exposed to extremely low doses of neutrons under different circumstances, such as through exposure to cosmic rays, nuclear accidents, and neutron therapy. Peripheral blood mononuclear cells (PBMCs) are the primary immune cells that exhibit selective immune responses. Changes in the functions of the protein components of PBMC can be induced by structural modifications of these proteins themselves. Herein, we have investigated the effect of low-dose fast neutrons on PBMC proteins at 0, 2, 4, and 8 days post-whole body irradiation. 64 Wistar rats were used in this study of which, 32 were exposed to fast neutrons at a total dose of 10 mGy (241Am-Be, 0.2 mGy/h), and the other 32 were used as controls. Blood samples were drawn, and PBMCs were isolated from whole blood. Fourier transform infrared (FTIR) spectroscopy and fluorescence spectroscopy were used to estimate the changes in the proteins of PBMCs. An alkaline comet assay was performed to assess DNA damage. Hierarchical cluster analysis (HCA) and principal components analysis (PCA) were utilized to discriminate between irradiated and non-irradiated samples. FTIR and fluorescence spectra of the tested samples revealed alterations in the amides and tryptophan, and therefore protein structure at time intervals of 2 and 4 days post-irradiation. No changes were recorded in samples tested at time intervals of 0 and 8 days post-irradiation. The FTIR band intensities of the PBMC proteins of the irradiated samples decreased slightly and were statistically significant. Curve fitting of the amide I band in the FTIR spectra showed changes in the secondary structure of the proteins. At 2 days post-irradiation, fluorescence spectra of the tested samples revealed decreases in the band tryptophan. The comet assay revealed low levels of DNA damage. In conclusion, low-dose fast neutrons can affect the proteins of PBMC.
Collapse
Affiliation(s)
- Abdu Saeed
- Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.
- Department of Physics, Thamar University, Thamar, Yemen.
| | - Mohammad N Murshed
- Department of Physics, Faculty of Science and Arts, Mohayel Aser, King Khalid University, Abha, Saudi Arabia
- Department of Physics, Faculty of Science, Ibb University, Ibb, Yemen
| | - Eman Abdulqader Al-Shahari
- Department of Biology, Faculty of Science and Arts, Mohayel Aser, King Khalid University, Abha, Saudi Arabia
- Department of Biology, Faculty of Science, Ibb University, Ibb, Yemen
| |
Collapse
|
12
|
Residential Radon in Central and South America: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17124550. [PMID: 32599800 PMCID: PMC7345538 DOI: 10.3390/ijerph17124550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/08/2020] [Accepted: 06/20/2020] [Indexed: 12/28/2022]
Abstract
Radon gas is a pulmonary carcinogen and the second leading cause of lung cancer after smoking. There are many countries that have not implemented measures to reduce the risk it poses to the general population. The aim of this study was to locate available evidence on exposure to residential radon and the regulations to monitor and control this across Central and South America, by conducting a review of the scientific literature and government documents in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This review included 31 studies which had taken measurements of radon in these countries. While Brazil, Argentina, and Peru have undertaken most research, no country in Central and South America has a national map of exposure to residential radon. The prevalence of exposure to radon was uneven, both among the different countries and within individual countries. No country has regulations to prevent the entry of radon into homes, and nine countries have not set maximum permissible concentrations for residential radon. There is a limited number of studies in South and Central America, with a limited spatial coverage, and there is a need to improve knowledge on exposure to residential radon and its effects, and for governments to take the necessary actions to introduce preventive measures in their statutory regulations.
Collapse
|