Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 592
Filtrar
1.
J Environ Radioact ; 276: 107448, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38749215

RESUMEN

Among environment contaminants, 210Pb and 210Po have gained significant research attention due to their radioactive toxicity. Moss, with its exceptional adsorption capability for these radionuclides, serves as an indicator for environmental 210Pb and 210Po pollution. The paper reviews a total of 138 articles, summarizing the common methods and analytical results of 210Pb and 210Po research in moss. It elucidates the accumulation characteristics of 210Pb and 210Po in moss, discusses current research challenges, potential solutions, and future prospects in this field. Existing literature indicates limitations in common measurement techniques for 210Pb and 210Po in moss, characterized by high detection limits or lengthy sample processing. The concentration of 210Pb and 210Po within moss display substantial variations across different regions worldwide, ranging from

Asunto(s)
Briófitas , Radioisótopos de Plomo , Polonio , Monitoreo de Radiación , Radioisótopos de Plomo/análisis , Polonio/análisis , Briófitas/química , Monitoreo de Radiación/métodos
2.
Mar Pollut Bull ; 203: 116500, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38762937

RESUMEN

The study on natural radionuclides in edible bivalves from the Cochin backwater lagoon, Kerala, employing alpha spectrometry, revealed higher concentrations of 210Po and 210Pb compared to 238U and 232Th. The annual committed effective dose (ACED) for the adult coastal population was calculated at a range of 1494.9 to 5783.4 µSv y-1, with 210Po being the predominant contributor, responsible for about 85 % of the dose. This highlighted significant health risks, underscored by a calculated cumulative mortality and morbidity risk range between 5.23 × 10-3 and 2.02 × 10-2. These findings emphasized the need for further research and the development of regulatory measures to mitigate exposure risks.


Asunto(s)
Bivalvos , Monitoreo de Radiación , Contaminantes Radiactivos del Agua , Animales , India , Contaminantes Radiactivos del Agua/análisis , Polonio/análisis , Torio/análisis , Radioisótopos de Plomo/análisis , Humanos
3.
Food Chem ; 450: 139266, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-38653045

RESUMEN

90Sr and 210Pb are considered to be key radionuclides in internal exposure resulting from dietary intake, however, the established methods employed for their detection are time-comsuming. A method for the sequential separation of 90Sr and 210Pb using a Sr·spec resin by LSC measurement is developed, which is highly suitable for food safety monitoring as its minimal sample requirements. The sequential separation of Sr and Pb from the sample was using 0.05 mol/L HNO3 and 0.05 mol/L C6H5O7(NH4)3. The chemical recoveries of Sr and Pb measured using ICP-OES were 72-83% and 80-88%, respectively. The minimum detectable activities of 90Sr and 210Pb in the food sample were 36.2 mBq/kg and 28.6 mBq/kg, respectively, obtained from a 0.1 kg fresh sample and 300 min counting time. The method was validated using reference materials and compared with other methods. The feasibility of the developed method for other highly complex food matrices needs further investigation.


Asunto(s)
Radioisótopos de Plomo , Conteo por Cintilación , Radioisótopos de Estroncio , Radioisótopos de Estroncio/análisis , Radioisótopos de Estroncio/aislamiento & purificación , Conteo por Cintilación/instrumentación , Radioisótopos de Plomo/análisis , Contaminación Radiactiva de Alimentos/análisis , Análisis de los Alimentos
4.
Environ Sci Pollut Res Int ; 31(22): 31664-31678, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38649600

RESUMEN

As a decay product of uranium series, 210Pb spreads widely in the nature and imposes strong radiological and chemical toxicity. It is vital to establish reliable and efficient radioanalytical methods for 210Pb determination to support environment and food radioactivity monitoring programs. This article critically reviews analytical methods developed for determining 210Pb in environmental and biological samples, especially new development in recent years. Techniques applied throughout different analytical steps including sample pretreatment, separation, purification, and detection are summarized and their pros and cons are discussed to provide a holistic overview for 210Pb environmental and biological assay.


Asunto(s)
Radioisótopos de Plomo , Radioisótopos de Plomo/análisis , Monitoreo de Radiación/métodos , Monitoreo del Ambiente/métodos
5.
J Trace Elem Med Biol ; 84: 127452, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38626651

RESUMEN

BACKGROUND: Plants' raw materials can accumulate chemical elements, including radioisotopes, to some extent and reflect the region they grow in. Due to their high environmental content and toxicity, natural radionuclides - polonium 210Po and lead 210Pb are the most dangerous radioisotopes for human health. METHODS: 70 raw medicinal herbal materials from 54 popular wild-growing medicinal plant species, most of them included in the European Pharmacopoeia, were collected across three regions. In 210 samples, the activity concentrations of 210Po and 210Pb were determined, and their radiotoxicity and cancer risk were calculated. RESULTS: The results of 210Po and 210Pb activities measured in herbal raw material were from 0.12 mBq g-1 dry weight in the fruits of the common chestnut (Aesculus hippocastanum) to 19.7 mBq g-1 dw in herb of ground elder (Aegopodium podagraria) for 210Po, while for 210Pb ranged from 0.16 mBq g-1 dw to 34.3 mBq g-1 dw in the same plants. There were statistically significant differences between 210Po and 210Pb content in leaves, herbs, flowers, and fruit. The studies indicated that the estimated annual effective radiation dose from Polish medicinal herbs consumption was low, ranging 0.03-105 µSv from 210Po and 0.02-98.2 µSv from 210Pb, while the risk of cancer morbidity and mortality ranged from 10-5 to 10-9. CONCLUSIONS: Consumption of the tested medicinal herbs is safe from the radiological point of view and, based on the predictions related to the calculated risk of cancer, should not increase the probability of its occurrence.


Asunto(s)
Radioisótopos de Plomo , Plantas Medicinales , Polonio , Polonio/análisis , Radioisótopos de Plomo/análisis , Plantas Medicinales/química , Humanos , Medición de Riesgo , Neoplasias
6.
J Environ Qual ; 53(3): 378-389, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38481362

RESUMEN

Herbal plants are considered natural pharmaceuticals but also accumulate chemical elements and compounds at high levels. 210Po and 210Pb are highly radiotoxic and may cause carcinogenesis due to ionizing radiation. Thirteen of the most popular wild-growing herbaceous plant species, mostly included in the European Pharmacopoeia, were collected across Ukraine. 210Po and 210Pb were determined in the medicinal plants, and their radiotoxicity and cancer risk were calculated. The results of 210Po activities measured in herbal raw material ranged from 2.28 Bq kg-1 dw (where dw is dry weight) in herb of common horsetail (Equisetum arvense L.) collected near Lviv to 37.7 Bq kg-1 dw in leaves of common birch (Betula pendula Roth.) from Rava Ruska. The activity concentrations of 210Pb varied from 0.44 Bq kg-1 dw in leaves of common birch from Starokostyantyniv to 28.4 Bq kg-1 dw in leaves of common birch from Mizhhirya. There were statistically significant differences between 210Po and 210Pb content in flowers, leaves, and aerial portions. The studies indicated that the estimated annual effective radiation dose from Ukrainian herbs consumption was low, ranging 5.00-82.6 µSv from 210Po and 0.56-35.8 µSv from 210Pb, while the cancer morbidity and mortality risk ranged from 10-4 to 10-6. The presented data indicated no radiological risk related to using herbal plant materials.


Asunto(s)
Radioisótopos de Plomo , Plantas Medicinales , Polonio , Radioisótopos de Plomo/análisis , Ucrania , Plantas Medicinales/química , Polonio/análisis , Neoplasias , Monitoreo de Radiación/métodos , Medición de Riesgo , Humanos
7.
Radiat Environ Biophys ; 63(1): 133-141, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38411924

RESUMEN

This study aimed to assess the concentrations of 210Po and 210Pb in various tobacco samples from Palestine and Jordan. Cigarette smoking is recognized as a significant contributor to the radiation dose received by individuals, primarily due to the elevated levels of 210Pb and 210Po found in tobacco. The analysis revealed that the average concentrations of 210Po in locally sourced tobacco and cigarette samples in Palestine are 16.8 ± 2.3 mBq/g and 18.5 ± 2.0 mBq/g, with a total average of 17.8 ± 7.4 mBq/g (15.5 mBq/cigarette). Similarly, the average concentrations of 210Pb in these samples are 18.5 ± 2.6 mBq/g and 20.3 ± 2.2 mBq/g, with a total average of 19.6 ± 8.1 mBq/g (17.0 mBq/cigarette). In Jordan, the average concentrations of 210Po in cigarette samples and narghile tobacco are 20.1 ± 2.4 mBq/g and 18.3 ± 4.1 mBq/g, with a total average value of 19.6 ± 9.9 mBq/g (18.0 mBq/cigarette), while the average concentrations of 210Pb are 22.2 ± 2.6 mBq/g and 20.2 ± 4.5 mBq/g, with a total average value of 21.6 ± 10.8 mBq/g (19.9 mBq/cigarette). The annual effective doses resulting from inhalation were calculated for smokers of these samples. The findings revealed that the levels of 210Po and 210Pb radioactivity in certain investigated samples exceeded the results of studies in many countries of the world. The associated effective doses per year from smoking for all brands products in Palestine range from 34.7 µSv/y to 186.5 µSv/y with an average of 109.5 µSv/y, while in Jordan 54.5 µSv/y to 289.1 µSv/y with an average of 130.9 µSv/y.


Asunto(s)
Polonio , Radiactividad , Productos de Tabaco , Jordania , Plomo/análisis , Radioisótopos de Plomo/análisis , Polonio/análisis , Productos de Tabaco/análisis
8.
Bull Environ Contam Toxicol ; 112(2): 31, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38291262

RESUMEN

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


Asunto(s)
Contaminantes Atmosféricos , Polonio , Humanos , Material Particulado/análisis , Polonio/análisis , Plomo , Turquía , Monitoreo del Ambiente , Radioisótopos de Plomo/análisis , Contaminantes Atmosféricos/análisis
9.
Radiat Environ Biophys ; 63(1): 125-131, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38055043

RESUMEN

The radon decay product 210Pb is a known component of tobacco. In this study, the activity concentration of 210Pb in the most popular cigarette brands (six samples) for Kazakhstan consumers was determined by beta spectrometry. The activity levels of 210Pb ranged between 2.69 ± 0.27 and 27.42 ± 2.74 mBq per cigarette. Higher activity concentrations for 210Pb were found in Sample No.4 and showed an excess of the world average by 1.8 times. The average activity concentrations of 210Pb in cigarette tobacco were 10.42 ± 1.04 mBq cig-1. The daily activities inhaled in the lungs of a smoker, and the resulting effective doses due to cigarette smoking were calculated. Effective doses per year due to cigarette smoking were calculated assuming that 42.13% of the 210Pb in tobacco were retained in the lungs of the smokers. It is concluded that for a smoker in Kazakhstan, the average effective dose ranges from 9.1 ± 0.9 µSv/year to 92.8 ± 9.3 µSv/year for a cigarette consumption of one pack of cigarettes per day. The results indicate that the annual effective doses from inhalation of 210Pb due to smoking one pack of cigarettes per day are from 7 to 58 times (for different types of cigarettes) greater than the annual effective doses from ingestion of radionuclides via the diet.


Asunto(s)
Polonio , Productos de Tabaco , Kazajstán , Plomo , Radioisótopos de Plomo/análisis , Polonio/análisis
10.
J Environ Radioact ; 270: 107314, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37866319

RESUMEN

Conventional 210Pb-dating models use assumptions on sedimentary conditions that allow for analytical formulations. The novel χ-mapping models use numerical methods to generate and test a large number (∼106) of potential solvers. Empirical data (excess 210Pb vs. mass depth profile) serve to attract the solver that minimizes the χ function (the attractor), and it has been assumed that it also defines the most likely chronology. This work aims to test this assumption in a deep way. In synthetic and varved sediments, the performance of each solver can be quantified through a parameter ξa accounting for the deviation of the model and the true ages. This work studies the complex relationships between χ and ξa using the constant flux (χ-CF) and the constant sediment accumulation rate (CSAR) models, which operate in a parametric 3D space. The full mapping of the 3D χ function serves to find the absolute minimum, for the graphical representation of the complex topology of the attractors, which is model-specific, and for plotting clouds of chronological lines from solvers with varying χ values. The minimum value of ξa (the best chronology) is achieved for a wide range of χ values, including the region of the absolute minimum. In complex cases, tiny changes in χ can result in quite different chronologies. Alternative attractors that include a reference date and an objective function are studied. The results provide guidelines for strengthening the 210Pb-based chronologies.


Asunto(s)
Monitoreo de Radiación , Monitoreo de Radiación/métodos , Plomo , Radioisótopos de Plomo/análisis , Sedimentos Geológicos , Monitoreo del Ambiente/métodos
11.
Mar Pollut Bull ; 194(Pt B): 115353, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37572432

RESUMEN

The atmospheric bulk depositional fluxes of 210Pb were measured at a station on the Adriatic coast, Croatia over 4 years period from March 2017 to December 2020. The monthly depositional fluxes followed oceanic deposition patterns with a lower flux between 0.0735 and 16.9 Bq m-2 month-1. The volume-weighted activities were 0.000514 and 1.35 Bq L-1 and decreased with increasing precipitation. A clear seasonal trend was observed with higher depositional flux in autumn and minimum value in the winter season. The average annual bulk depositional flux and volume-weighted activities of 210Pb were 73.8 Bq m-2 y-1 and 0.119 Bq L-1 respectively. The precipitation normalized enrichment factor (α) indicates higher depositional fluxes of 210Pb during summer and spring than desired value according to the amount of precipitation. We found that the 210Pb depositional fluxes in the coastal stations are lower due to 210Pb-depleted oceanic air masses and increase with the amount of precipitation.


Asunto(s)
Contaminantes Radiactivos del Aire , Radioisótopos de Plomo , Radioisótopos de Plomo/análisis , Plomo , Croacia , Berilio/análisis , Contaminantes Radiactivos del Aire/análisis , Estaciones del Año , Monitoreo del Ambiente
12.
J Environ Radioact ; 268-269: 107248, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37515861

RESUMEN

The 210Pb-based method has been widely used for five decades to determine absolute ages in recent sediments on the centennial scale. Decoding a chronology from the empirical data set requires a series of assumptions that define a mathematical model of the sedimentary conditions. This work aims to provide a comprehensive review of the fundamentals of the existing family of models assuming a constant flux of excess 210Pb at the sediment surface, namely the CFCS, CRS, and PLUM models, and to present the novel χ-mapping versions of the CFCS and CF models. Their performance is assessed with a selected group of five cores from literature data, with varve chronologies or independent time marks. The PLUM model did not produce reliable chronologies in any of the cores studied. The CRS model is too sensitive to an accurate estimation of the total inventory. A weighted-fit and the χ-mapping versions of the CFCS model are prone to over-represent the younger regions of the core. The CFCS model with least squares fitting and the χ-CF models performed best under the most common sedimentary conditions, which involve temporal variability in the fluxes randomly distributed in the time line. A practical strategy is suggested to identify the occurrence of such sedimentary conditions through the combined use of a set of models, providing this way further strength to the 210Pb-dating.


Asunto(s)
Prunus domestica , Monitoreo de Radiación , Plomo , Radioisótopos de Plomo/análisis , Sedimentos Geológicos , Monitoreo del Ambiente/métodos
13.
J Environ Radioact ; 268-269: 107247, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37499335

RESUMEN

The 210Pb-based method aims at determining the absolute age of recent sediments on the centennial scale. A family of models assumes that at the sediment-water interface the flux of unsupported 210Pb (210Pbexc), F, relates to its initial activity concentration, Ao, and the mass sedimentation rate, w, as: F=Aow. Additional specific assumptions that allow for analytical formulations of the models are: i) constant Ao (CIC), constant F (CF), and constant F with constant w (CFCS). A model with constant w (CSAR) was suggested for completeness but never used because of the lack of a suitable analytical formulation. The TERESA model assumes random and independent variability for Ao and w, described by normal distributions. It systematically generates a large number (∼105) of potential solutions, whose performance for fitting the empirical 210Pbexc profile is quantified through the χ-function. This work aims to adapt the above methodology to formulate the χ-mapping version of the CSAR model. The performance of the model is evaluated with a set of synthetic and real cores for which an independent chronology is available. CSAR is able to capture the mean sedimentation rate from the 210Pbexc data and provides reliable chronologies and paleorecords of Ao, useful for tracking past changes in sedimentary conditions. CSAR provides an interesting different perspective for researchers working with 210Pb-based dating of recent sediments.


Asunto(s)
Monitoreo de Radiación , Monitoreo de Radiación/métodos , Sedimentos Geológicos , Plomo , Radioisótopos de Plomo/análisis , Agua , Monitoreo del Ambiente/métodos
14.
Mar Pollut Bull ; 188: 114591, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36682306

RESUMEN

Algae are believed to give health benefits. However, the studies showed they contain toxic elements, including radionuclides, and may affect human health. The study presents the values of activity concentrations of 210Po and 210Pb in the algae supplements available worldwide for adults. The activity concentrations (Bq/kg dw) ranged from 0.07 to 14.5 (210Po) and from 0.06 to 8.48 (210Pb). Also, the effective radiation doses and the cancer risk from 210Po and 210Pb decay ingested with analyzed algal supplements have been assessed. The highest values of annual effective doses have been estimated for 210Po in the recommended portion of Spirulina (Arthrospira platensis) from China (59.7 µSv/year) and Diatomaceous earth from the USA (50.4 µSv/year). The cancer morbidity and mortality risk ranged from 10-4 to 10-8. The study indicated the activity concentrations of 210Po and 210Pb were low, and algae supplements for human consumption could be considered safe food.


Asunto(s)
Polonio , Monitoreo de Radiación , Humanos , Plomo , Radioisótopos de Plomo/análisis , Polonio/análisis , Dieta
15.
Environ Geochem Health ; 45(4): 1173-1181, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35318556

RESUMEN

Chronologies generated from core profiles to apply dates to environmental changes commonly use the measurement of the activity of radionuclides deposited and stratified with physical environmental material. The most commonly reported nuclide to define chronologies covering the last 150 years is Pb-210, for which accepted data processing methodologies in the literature have focussed on the constant rate of supply (CRS) model and the more recently published Bayesian Plum model. This short communication describes a validation approach using defined sediment layers referred to as 'varve' counting, which provide known points of reference to account for uncertainty between generated dates from each model using published Pb-210 measurements. A significant improvement in the chronologies was observed when applying reference date corrections to the models. This was shown to be essential in providing confidence in reported datasets and accuracy of predicted chronologies, which will better inform the interpretation of environmental change, e.g. sedimentation rates, climate change, pollution pathways and land degradation. Generated chronologies from both the CRS and Plum methods showed good agreement with the established varve dates (typically < 4-year difference).


Asunto(s)
Sedimentos Geológicos , Radioisótopos de Plomo , Radioisótopos de Plomo/análisis , Teorema de Bayes , Monitoreo del Ambiente/métodos
16.
Appl Radiat Isot ; 192: 110601, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36481494

RESUMEN

This study describes a new and fast method for separating 210Po from 210Pb and 90Sr, before simultaneously measuring the individual activities of the latter two radionuclides using a plastic scintillation resin (PSresin) in sludge samples taken from a drinking water treatment plant. This method speeds up the analysis process significantly by simultaneously measuring 210Pb and 90Sr in a single step. The method is reproducible and has a relative standard deviation of less than 25% for 210Pb, 210Po and 90Sr. The method was satisfactorily validated with an intercomparison sample and applied to sludge samples from a drinking water treatment plant. The minimum detectable activities for 0.9 g of sludge are 5.5 Bq/kg and 8 Bq/kg for 210Pb and 90Sr respectively when measured for 180 min, and 0.5 Bq/kg for 210Po when measured for 5000 min.


Asunto(s)
Agua Potable , Polonio , Monitoreo de Radiación , Plásticos , Plomo , Aguas del Alcantarillado , Agua Potable/análisis , Polonio/análisis , Monitoreo de Radiación/métodos , Radioisótopos de Plomo/análisis
17.
Radiat Prot Dosimetry ; 198(13-15): 914-919, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36083718

RESUMEN

To evaluate 210Pb deposited on the surface of sea around Japan in detail, the performance of atmospheric transport/deposition model for 222Rn and its progenies was examined. To test the model's reproducibility of 210Pb deposition in winter, it was applied at Rokkasho in Aomori, where the model had been reported to significantly underestimate when the horizontal grid interval of 9 km was used. It was shown that the precipitation on the Pacific Ocean side and Mutsu Bay and hence the 210Pb deposition at Rokkasho were significantly improved with the grid interval of 3 km although the deposition was still underestimated by the observation. This underestimation was considered to be caused by model's neglect of horizontal drift of snow and rain. It was also pointed out that the deposited 210Pb was mainly contributed by the lower atmosphere up to 2-3 km.


Asunto(s)
Contaminantes Radiactivos del Aire , Radón , Contaminantes Radiactivos del Aire/análisis , Radioisótopos de Plomo/análisis , Reproducibilidad de los Resultados
18.
Radiat Prot Dosimetry ; 198(13-15): 891-895, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36083740

RESUMEN

A three-dimensional long-range atmospheric transport model for 222Rn and its progenies was applied to simulate 210Pb deposition in Japan and its adjacent waters. Monthly precipitation and 210Pb deposition simulated by the model for winter months were favorably compared with observational data although they were exceptionally underestimated in Aomori. The large monthly deposition along the Japan Sea coast lines during winter was successfully simulated by the model to be nearly 200 Bq m-2, which was contrasted by about 10-fold smaller deposition in other regions. It was also pointed out that the heavy deposition areas formed a narrow band structure along the coastline with width of several tens of kilometers and 210Pb deposition amount positively correlated with the height of mountains located leeward of the heavy deposition areas.


Asunto(s)
Contaminantes Radiactivos del Aire , Radón , Contaminantes Radiactivos del Aire/análisis , Asia Oriental , Japón , Radioisótopos de Plomo/análisis , Radón/análisis
19.
Radiat Prot Dosimetry ; 198(13-15): 1109-1114, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36083742

RESUMEN

I performed continuous gamma-ray measurements in seawater to observe the temporal variation of radon progenies ( 214Pb and 214Bi) derived from atmospheric precipitation. Underwater gamma-ray measurements using two NaI(Tl) detectors at different installation depths (1 and 4 m) were recorded from July to November 2011 at the marine observation buoy. An increase in the concentration of 214Pb + 214Bi in seawater was observed due to precipitation when the wind velocity was <2 m s-1. However, this increase was only detected at 1 m depth and a downward spread of 214Pb + 214Bi was not observed. In contrast, at a wind velocity of >8 m s-1, the 214Pb + 214Bi concentration ratio at 4 m/1 m was almost constant (0.6-0.7) for most of the measurement irrespective of precipitation intensity. Assuming one-dimensional diffusion in the water column, the apparent vertical diffusion coefficient estimated from the temporal variation of 214Pb + 214Bi concentrations at 4 m/1 m varied from <10 to 500 cm2 s-1 depending on the wind velocity.


Asunto(s)
Contaminantes Radiactivos del Aire , Radón , Contaminantes Radiactivos del Aire/análisis , Radioisótopos de Plomo/análisis , Radón/análisis , Hijas del Radón/análisis
20.
Radiat Prot Dosimetry ; 198(13-15): 1058-1065, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36083744

RESUMEN

This study revealed sedimentation processes based on 137Cs and 210Pb distribution, grain size and magnetic susceptibility of bottom sediments in West Nanao Bay, Japan. Surface sediment concentrations and inventories of these radionuclides were relatively low in the middle and eastern areas of the bay and high in the western area, which has several major river mouths, suggesting that the contribution of riverine input affected only the western area. In the middle and eastern areas, the level of 137Cs inventory was much lower than that of the soils, and the excess 210Pb inventory was at the same level or lower. These results indicate that removal effects are stronger than accumulation effects (riverine input) in these areas. The patterns of radionuclides were consistent with the results, that grain size was relatively large in the middle and eastern areas, implying strong current conditions, and that fine sediment accumulated less in these areas.


Asunto(s)
Radioisótopos de Cesio , Radioisótopos de Plomo , Radioisótopos de Cesio/análisis , Monitoreo del Ambiente , Sedimentos Geológicos , Japón , Radioisótopos de Plomo/análisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA