Uranium mining waste represents a considerable potential source of radon emissions in the nearby environment. The project's aim (2021-2024) was to observe and evaluate the effects of seasonal fluctuations in radon release from former uranium mine dumps No.15 and No.4 in the Příbram area and their influence on the surrounding atmosphere. The objective was to describe the radiation situation and homogeneity of the dumps and to record and analyze the impact of climatic conditions, which contribute to radon transport to the adjacent communities. The progressive phase involved aerial and field measurements of the Ambient Dose Equivalent Rate, detecting hot spots using an unmanned aerial vehicle (UAV), collecting air samples with Lukas cells, and continuously monitoring Radon Activity Concentration. Meteorological data filtered for conditions of temperatures, absence of wind, and no precipitation during night-time hours (from 8:00 p.m. to 6:00 a.m.) identified 890 days between 2005 and 2023. This corresponds to an average of 47 days per year during which conditions conducive to radon transport to the vicinity of the dumps were present, which, as determined, influences radon activity concentrations and their subsequent dispersion into the surrounding environment. These measurements confirmed elevated radon activity concentrations in the ambient air, exceeding several kBq/m³ with measured maxima of 27 kBq/m³. This project's integration of monitoring methods has resulted in a novel, comprehensive approach to determining radon transport from the dump to nearby communities. The ability to accurately identify areas with elevated Radon Activity Concentrations (RAC) plays a crucial role in optimizing strategies to mitigate the impact of radon decay products on public health.
- Klíčová slova
- Aerial measurements, Radon, Spatial analysis, UAV, Uranium mining,
- MeSH
- atmosféra chemie MeSH
- hornictví MeSH
- monitorování radiace * MeSH
- radioaktivní látky znečišťující vzduch * analýza MeSH
- radon * analýza MeSH
- roční období MeSH
- uran MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- radioaktivní látky znečišťující vzduch * MeSH
- radon * MeSH
- uran MeSH
In the Czech Republic, underground or mixed source water treatment plants are classified as the workplaces with possible increased exposure from a natural source of radiation. When releasing waste materials or residues from these NORM workplaces into the environment, the content of natural radionuclides is measured and compared with the clearance levels established by Czech legislation. The content of natural radionuclides in solid samples is determined primarily by high-resolution gamma-ray spectrometry. Six radionuclides, 238U, 228Th, 226Ra, 228Ra, 210Pb, 40K, are measured directly or by their measurable decay products (assuming equilibrium), the activity concentration of the other four radionuclides, 234U, 230Th, 210Po, 232Th is conservatively estimated. The study is focused on mapping the properties of NORM arising from the treatment of groundwater and, based on the real samples measurement, verification of new proposed assessment approach. It was tested whether the knowledge of the content of natural radionuclides in water can be practically used to estimate the content in NORM. Samples of water, filter material or sludge were taken from 16 different water treatment plants. Combination of gamma-ray spectrometry and radiochemical methods were applied to determine the content of radionuclides 234U, 238U, 226Ra, 228Ra, 228Th, 230Th and 232Th in solid NORM, and radionuclides 234U, 238U, 226Ra, 228Ra in water. Based on the results the proposed modification of the assessment was verified.
- Klíčová slova
- Disequilibrium in decay series, NORM, Water treatment plant,
- MeSH
- čištění vody metody MeSH
- monitorování radiace * metody MeSH
- radioaktivní látky znečišťující vodu * analýza MeSH
- radium * analýza MeSH
- spektrometrie gama MeSH
- thorium * analýza MeSH
- uran * analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- radioaktivní látky znečišťující vodu * MeSH
- radium * MeSH
- thorium * MeSH
- uran * MeSH
Most plant research focuses on the responses immediately after exposure to ionizing irradiation (IR). However, it is as important to investigate how plants recover after exposure since this has a profound effect on future plant growth and development and hence on the long-term consequences of exposure to stress. This study aimed to investigate the IR-induced responses after exposure and during recovery by exposing 1-week old A. thaliana seedlings to gamma dose rates ranging from 27 to 103.7 mGy/h for 2 weeks and allowing them to recover for 4 days. A high-throughput RNAsequencing analysis was carried out. An enrichment of GO terms related to the metabolism of hormones was observed both after irradiation and during recovery at all dose rates. While plants exposed to the lowest dose rate activate defence responses after irradiation, they recover from the IR by resuming normal growth during the recovery period. Plants exposed to the intermediate dose rate invest in signalling and defence after irradiation. During recovery, in the plants exposed to the highest dose rate, fundamental metabolic processes such as photosynthesis and RNA modification were still affected. This might lead to detrimental effects in the long-term or in the next generations of those irradiated plants.
- MeSH
- Arabidopsis * MeSH
- monitorování radiace * MeSH
- rostliny MeSH
- semenáček účinky záření MeSH
- záření gama MeSH
- Publikační typ
- časopisecké články MeSH
Humans receive a significant portion (˃50%) of the total dose attributed to all the natural radiation sources from indoor radon (222Rn), thoron (220Rn), and their progeny. While progeny contributes an overwhelming part to the dose, in most surveys, only radon gas is measured because of the simplicity of measurement. Progeny concentration is usually estimated by multiplying gas concentration with an assumed factor, called the equilibrium factor, and taken from literature. Recently, results of the measurements of equilibrium factors for 222Rn and 220Rn were reported from various parts of the globe. In India, many such studies have been conducted in the current decade. The studies show a wide variation of equilibrium factors which suggests that they depend on environmental factors and measurement conditions. Therefore, they should be determined site specifically if accurate site-specific dose estimation is targeted. This paper summarizes concepts, definitions, and methods to determine equilibrium factors and reviews literature about reported equilibrium factors worldwide, focusing on data reported from India.
- Klíčová slova
- (220)Rn, (222)Rn, Equilibrium factors, India, Inhalation dose, Site-specific,
- MeSH
- bydlení MeSH
- dceřiné produkty radonu analýza MeSH
- lidé MeSH
- monitorování radiace * metody MeSH
- radioaktivní látky znečišťující vzduch * analýza MeSH
- radon * analýza MeSH
- znečištění vzduchu ve vnitřním prostředí * analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Indie MeSH
- Názvy látek
- dceřiné produkty radonu MeSH
- radioaktivní látky znečišťující vzduch * MeSH
- radon * MeSH
Anaerobic digestion (AD) is a widely used technology that allows for the reprocessing and reduction of waste biomass. A study was conducted to see if the AD technology might be used to process radioactively polluted agricultural biomass. For this purpose, laboratory tests were carried out with a 20-liter model biogas plant (BGP) with the radionuclide 134Cs and operational tests with the South Bohemian commercial biogas plant monitoring the radionuclide 137Cs. The activities of 134Cs in inputs, contaminated grass or maize silage and in emerging fractions were investigated in the model fermenter. The activity of 134Cs in the dry matter during the fermentation process increased by 46% on average, which corresponds to a reduction of dry matter by 43% due to the production of biogas. 137Cs activities were measured in commercial BGP maize, grass, and whole plant silage, wheat, digestate, biogas, and aerosol samples. The commercial BGP fermentation process was more efficient, with an 80% reduction in dry mass weight. Dry biomass (1.37 Bq/kg) had a 137Cs massic activity that was 4.4 times lower than the activity of dry digestate mass (6.01 Bq/kg). The activity of the 137Cs in biogas aerosol was 1.1 × 10-7 Bq/m3 or less, and the decontamination factor was 6.9 × 106 or greater. Most Cs remain in the digestate. No other ways of radioactivity leakage have been identified.
- Klíčová slova
- (137)Cs, Biogas technology, Biomass, Waste processing,
- MeSH
- anaerobióza MeSH
- biomasa MeSH
- biopaliva * MeSH
- bioreaktory MeSH
- kukuřice setá MeSH
- lipnicovité MeSH
- monitorování radiace * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biopaliva * MeSH
- Cesium-134 MeSH Prohlížeč
- Cesium-137 MeSH Prohlížeč
Samples of fly ash, slag and boiler scale containing elevated amounts of uranium or lead (210Pb) from several coal-fired power stations in the Czech Republic were collected for an assessment of their dissolution parameters - the dissolution rates and their respective fractions in vitro. The dissolution data were fitted either by a biexponential model or by a triexponential model. The uranium 234U and 238U in the fly ash sample are classified as M-type. Similarly, type M could be attributed for most of the materials containing 210Pb. A complementary measurement of the activity concentrations of 210Pb in relation to the grain size confirmed that the radionuclide is deposited mainly in fine particles (<25 μm).
- Klíčová slova
- Boiler scale, Dissolution kinetics, Fly ash, Lead, Occupational exposure,
- MeSH
- elektrárny MeSH
- monitorování radiace * MeSH
- olovo MeSH
- plíce chemie MeSH
- popel uhelný analýza MeSH
- rozpustnost MeSH
- uhlí MeSH
- uran * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- olovo MeSH
- popel uhelný MeSH
- uhlí MeSH
- uran * MeSH
Predictions of radionuclide dose rates to freshwater organisms can be used to evaluate the radiological environmental impacts of releases from uranium mining and milling projects. These predictions help inform decisions on the implementation of mitigation measures. The objective of this study was to identify how dose rate modelling could be improved to reduce uncertainty in predictions to non-human biota. For this purpose, we modelled the activity concentrations of 210Pb, 210Po, 226Ra, 230Th, and 238U downstream of uranium mines and mills in northern Saskatchewan, Canada, together with associated weighted absorbed dose rates for a freshwater food chain using measured activity concentrations in water and sediments. Differences in predictions of radionuclide activity concentrations occurred mainly from the different default partition coefficient and concentration ratio values from one model to another and including all or only some 238U decay daughters in the dose rate assessments. Consequently, we recommend a standardized best-practice approach to calculate weighted absorbed dose rates to freshwater biota whether a facility is at the planning, operating or decommissioned stage. At the initial planning stage, the best-practice approach recommend using conservative site-specific baseline activity concentrations in water, sediments and organisms and predict conservative incremental activity concentrations in these media by selecting concentration ratios based on species similarity and similar water quality conditions to reduce the uncertainty in dose rate calculations. At the operating and decommissioned stages, the best-practice approach recommends relying on measured activity concentrations in water, sediment, fish tissue and whole-body of small organisms to further reduce uncertainty in dose rate estimates. This approach would allow for more realistic but still conservative dose assessments when evaluating impacts from uranium mining projects and making decision on adequate controls of releases.
- Klíčová slova
- Environmental modelling, Freshwater ecosystems, Uranium series radionuclides, Wildlife dose assessment,
- MeSH
- hornictví MeSH
- monitorování radiace * MeSH
- radionuklidy analýza MeSH
- sladká voda MeSH
- uran * analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Saskatchewan MeSH
- Názvy látek
- radionuklidy MeSH
- uran * MeSH
Safecast is a citizen science project, aimed to environmental monitoring. Its main activity is measuring ambient dose rate all over the world. The freely accessible data, currently (January 2020) more than 120 million observations, were used to calculate mean values of dose equivalent rate in various cities where sufficient data is available. The results mainly reflect dose rate from terrestrial radiation, whose variability is controlled by the one of geochemistry, namely the concentrations of uranium, thorium and potassium. Further influence comes from cosmic radiation and in a few cases, from anthropogenic radiation caused by nuclear fallout. Mean dose rate has been calculated for 330 cities and towns worldwide. Results are shown in tables, graphs and as maps.
- Klíčová slova
- Ambient dose rate, Citizen science, Safecast, Urban environment,
- MeSH
- dávka záření * MeSH
- monitorování radiace * MeSH
- radioaktivní látky znečišťující půdu analýza MeSH
- radioizotopy draslíku analýza MeSH
- thorium analýza MeSH
- uran analýza MeSH
- velkoměsta MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- velkoměsta MeSH
- Názvy látek
- radioaktivní látky znečišťující půdu MeSH
- radioizotopy draslíku MeSH
- thorium MeSH
- uran MeSH
Atmospheric activity concentration of 7Be in the air was monitored during the period of one year from September 2015 to September 2016 at Ostrava, Czech Republic, with a two-day frequency that is shorter compared to a standard 7-day frequency of routine 7Be measurements. Simultaneously, relevant meteorological data (temperature, rainfall amount, precipitation particle size and speed, tropopause height, and PM10 concentrations) and the sunspot number were accumulated. Weighted linear regression analysis applied to the 7Be atmospheric activity concentration, the measured meteorological explanatory variables and the sunspot number revealed temperature as the most statistically significant explanatory variable. The tree model proved temperature as the most important explanatory variable and predicted the threshold value separating low and high temperature behavior of 7Be at about 13 °C (2-day average). A simple local two-layer (stratosphere and troposphere) atmospheric model was then applied to the data analysis. The model is able to fit the data for a larger accumulation period (6 days).
- MeSH
- beryllium MeSH
- časové faktory MeSH
- látky znečišťující vzduch MeSH
- monitorování radiace * MeSH
- monitorování životního prostředí MeSH
- radionuklidy MeSH
- roční období MeSH
- teplota MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- Beryllium-7 MeSH Prohlížeč
- beryllium MeSH
- látky znečišťující vzduch MeSH
- radionuklidy MeSH
