scholarly journals Difference of ecological half-life and transfer coefficient in aquatic invertebrates between high and low radiocesium contaminated streams

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mayumi Yoshimura ◽  
Akio Akama
Keyword(s):  
Transfer Coefficient ◽  
Dose Rate ◽  
Half Life ◽  
Aquatic Invertebrates ◽  
Stream Ecology ◽  
Freshwater Ecosystems ◽  
Fukushima Accident ◽  
Freshwater Streams ◽  
Slow Velocity ◽  
Contaminated Streams

AbstractThe Fukushima accident emitted radioactive substances into the environment, contaminating litter, algae, sand substrate, aquatic invertebrates, and fish in freshwater streams. Because these substances have substantial effects on stream ecology over many years, it is necessary to clarify the diffusion and decay mechanisms of radiocesium. The transfer coefficient differed among aquatic invertebrate groups, likely due to the differences in habitat. The ecological half-life of cesium was longer where the air dose rate was lower. The transfer coefficient was also higher in areas with lower air dose rate. The radiocesium concentration in algae was inversely related to stream current velocity in the radiocesium-contaminated area. However, this relationship was not observed in the lower air dose rate area: the radiocesium concentration in algae in the rapid-velocity areas tended to be higher than that in the slow-velocity areas. This reverse trend would lead to a longer period of freshwater contamination. The radiocesium concentration would continue to decrease in highly contaminated areas, but it would be difficult to reduce the radiocesium concentration in less-contaminated areas because different contamination mechanisms are at work. Controlling the water flow is key to regulating radiocesium concentration in freshwater ecosystems.

scholarly journals The OpenRadiation project: monitoring radioactivity in the environment by and for the citizens

2019 ◽  
Vol 54 (4) ◽  
pp. 241-246 ◽  
Author(s):  
J.F. Bottollier-Depois ◽  
E. Allain ◽  
G. Baumont ◽  
N. Berthelot ◽  
G. Darley ◽  
...  
Keyword(s):  
Emergency Management ◽  
Dose Rate ◽  
Scientific Community ◽  
Emergency Situation ◽  
Collaborative Approach ◽  
Fukushima Accident ◽  
The Public ◽  
Collaborative Tools ◽  
Share Data ◽  
Project Monitoring

After the Fukushima accident, initiatives emerged offering the public the possibility to realise measurements of the radioactivity in the environment with various devices and to share data and experiences through collaborative tools. The objective of the OpenRadiation project is to offer the public the opportunity to perform measurements of the radioactivity using connected dosimeters on smartphones. The challenge is to operate such a system on a sustainable basis in normal situations and in order to be useful in an emergency situation. In normal situations, this project is based on a collaborative approach including pedagogical activities. In case of emergency situation, data from the field will be available in “real time” providing an opportunity for the emergency management and the communication with the public. The practical objectives are to develop i) a website centralising measurements using various dosimeters, providing dose rate maps with raw and filtered data and offering dedicated areas for specific projects and exchanges about data and ii) a dosimetric app using a connected dosimeter. This project is conducted within a partnership between organisms’ representative of the scientific community and associations to create links with the public.

scholarly journals Monitoring of220Rn Concentrations in Buildings of Kufa Technical Institute, Iraq

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ali Abid Abojassim Al-Hamidawi
Keyword(s):  
Dose Rate ◽  
Half Life ◽  
Annual Effective Dose ◽  
Measuring System ◽  
Technical Institute ◽  
The Public ◽  
Effective Doses ◽  
Public Exposure ◽  
Effective Dose Rate ◽  
Annual Effective Dose Rate

This paper presents the measurements of thoron and the progeny in fifteen buildings in Kufa Technical Institute, Iraq, from June 2015 to April 2015 using RAD-7 detectors. Also, annual effective dose rate was calculated in all buildings under study. The thoron concentration varies from05.35±0.58 Bq/m3to53.50±1.82 Bq/m3with an average18.39±4.18 Bq/m3. The concentration of thoron daughters was found to vary from 0.14 mWL to 1.44 mWL with an average0.53±0.11 mWL. The annual effective doses due to thoron mainly vary from 0.042 mSv/y to 0.81 mSv/y with an average0.20±0.06 mSv/y. The preliminary results in this study indicate that they may be suitable for evaluating the indoor220Rn and its progeny concentrations whenever the public exposure to220Rn and its progeny is taken into account. During this survey, the continuous difficulty in measuring thoron was also pointed out, due to its short half-life and faults in the measuring system.

Ion lifetimes in irradiated gaseous HCl

1967 ◽  
Vol 45 (24) ◽  
pp. 3079-3082 ◽  
Author(s):  
D. A. Armstrong ◽  
R. A. Back
Keyword(s):  
Dose Rate ◽  
Gas Phase ◽  
Gamma Rays ◽  
Half Life ◽  
Field Method ◽  
Dose Rates ◽  
Phase Combination

An intermittent-field method has been used to measure ion lifetimes in gaseous HCl during irradiation by gamma rays under conditions of pressure, dose rate, and vessel geometry similar to those employed in radiolysis studies. At 23 °C, with HCl pressures from 119 to 660 Torr and dose rates from 5.5 to 86 × 1010 eV cc−1 s−1, the ion half-life ranged from 6 to 30 ms. The dependence on dose rate and pressure strongly indicated that ion neutralization occurred almost entirely in the gas phase. Values of α, the gas-phase combination coefficient, were calculated; at pressures above 246 Torr the value was constant and equal to 3.1 ± 0.3 × 10−6 cc ions−1 s−1. The addition of SF6 had little effect on α, while reducing the temperature to −79 °C increased α to 5.1 × 10−6.

An Inverse Method to Estimate Emission Rates of Multi-Radionuclides Based on an Ensemble 4DVar Method With Local Gamma Dose Rate Measurements

2018 ◽  
Author(s):  
Xiaobing Geng ◽  
Mei Xu ◽  
Lijun Zhang ◽  
Biao Yuan
Keyword(s):  
Data Assimilation ◽  
Transfer Coefficient ◽  
Dose Rate ◽  
Emergency Response ◽  
Estimation Method ◽  
Coefficient Matrix ◽  
Gamma Dose ◽  
Nuclear Accident ◽  
Gamma Dose Rate ◽  
Emission Rates

An inverse source estimation method is proposed to reconstruct emission rates of multi-radionuclides using local gamma dose rate measurements under the data assimilation framework. It involves the Proper Orthogonal Decomposition (POD)-based ensemble four-dimensional variational data assimilation (PODEn4DVar) algorithm and a transfer coefficient matrix (TCM) created using FLEXPART, a Lagrangian atmospheric dispersion model. PODEn4DVar is a hybrid data assimilation method that exploits the strengths of both the ensemble Kalman filter (EnKF) and the 4DVar assimilation method. With an explicit expression of control (state) variables in the cost functional, the data assimilation process is substantially simplified than traditional 4D variational method. By setting a unit emission rate and running the ATDM model (FLEXPART in this article) driven by meteorological fields forecasted with WRF, we get the transfer coefficient matrix with the progression of nuclear accident. TCM not only acts as observation operator in PODEn4DVar, but also eliminates the control run in traditional data assimilation framework. The method is tested by twin experiments with ratios of nuclides assumed to be known. With pseudo observations based on Fukushima Daiichi nuclear power plant (FDNPP) accident, most of the emission rates were estimated accurately, except under conditions when wind blew off land toward the sea and at extremely slow wind speeds near the FDNPP. Because of the long duration of accident and variability of meteorological fields, measurements from land only in local area is unable to offer enough information to support emergency response. With abundant measurements of gamma dose rate, emission rates can be reconstructed sequentially with the progression of nuclear accident. Therefore, the proposed method has the potential to be applied to nuclear emergency response after improvement.

scholarly journals Sustainability of UK forestry: contemporary issues for the protection of freshwaters, a conclusion

2004 ◽  
Vol 8 (3) ◽  
pp. 589-595 ◽  
Author(s):  
C. Neal ◽  
S. J. Ormerod ◽  
S. J. Langan ◽  
T. R. Nisbet ◽  
J. Roberts
Keyword(s):  
Water Quality ◽  
Critical Loads ◽  
Stream Ecology ◽  
Freshwater Ecosystems ◽  
Atmospheric Pollutants ◽  
Environmental Research ◽  
Earth System ◽  
Special Issue ◽  
Freshwater Organisms ◽  
Research Findings

Abstract. This paper closes the Special Issue of Hydrology and Earth System Sciences entitled "Sustainability of UK forestry: contemporary issues for the protection of freshwaters" by presenting conclusions from the contributions together with associated research findings. The volume deals largely with issues of upland water quality and biology in the context of environmental research and management. The studies are linked to an array of issues which affect the sustainability of UK forestry in the context of the protection of freshwaters, freshwater ecosystems and freshwater organisms. These issues include atmospheric and climate driven factors (acidification from atmospheric pollutants, critical loads, climate-change and climate variability), forestry practice and hydrobiogeochemical processing both within-catchments and within-rivers. The findings lie within the context of the science and relate to environmental management. Keywords: water quality, forestry, stream ecology, acidification, critical loads, nutrients

scholarly journals Mayfly response to different stress types in small and mid-sized lowland rivers

ZooKeys ◽  
2020 ◽  
Vol 980 ◽  
pp. 57-77
Author(s):  
Marina Vilenica ◽  
Mladen Kerovec ◽  
Ivana Pozojević ◽  
Zlatko Mihaljević
Keyword(s):  
Aquatic Invertebrates ◽  
Aquatic Vegetation ◽  
Freshwater Ecosystems ◽  
Catchment Scale ◽  
Lowland Rivers ◽  
Lowland Streams ◽  
Taxa Richness ◽  
Study Sites ◽  
High Share ◽  
Cloeon Dipterum

Freshwater ecosystems are endangered worldwide by various human pressures, resulting in dramatic habitat and species loss. Many aquatic invertebrates respond to disturbances in their habitat, and mayflies are among the most sensitive ones. Therefore, we investigated mayfly response to anthropogenic disturbances at 46 study sites encompassing slightly to heavily modified small and mid-sized lowland streams and rivers. Mayfly nymphs were sampled between April and September 2016 using a benthos hand net. A total of 21 species was recorded, with Cloeon dipterum (Linnaeus, 1761) being the most frequently recorded one. Nevertheless, the taxa richness was rather low per site, i.e., between zero and nine. Assemblage structure had a high share of lower reaches and lentic (potamic and littoral) elements, and detritivores (gatherers/collectors and active filter feeders). This indicates that hydromorphological alterations lead to assemblage “potamisation” in small and mid-sized rivers. More mayfly species were related to higher oxygen concentration and lower water temperature, abundance of aquatic vegetation and total organic carbon. Additionally, the assemblage diversity and abundance were negatively associated with increasing intensive agriculture area at the catchment scale. This study confirms mayfly bio-indicative properties, i.e., their sensitivity to alterations of their habitat and pollution, but also provides new data related to mayfly response to the impacted environment. Those data can be used for management and protection activities of lowland rivers and their biota according to the requirements of the European Water Framework Directive.

Disposition Kinetics of lincomycin following intravenous administration in hypothyroid goats

2019 ◽  
Author(s):  
Meemansha Sharma ◽  
Vinod Kumar Dumka ◽  
Saloni Singla ◽  
Rajdeep Kaur ◽  
Raushan Kumar Singh
Keyword(s):  
Dose Rate ◽  
Intravenous Administration ◽  
Half Life ◽  
Total Body Clearance ◽  
Small Ruminants ◽  
Blood Samples ◽  
Elimination Half ◽  
Total Body ◽  
Kinetics Of ◽  
Body Clearance

Hypothyroidism is a common disorder of small ruminants and is expected to alter the pharmacokinetics of drugs. Hypothyroidism was induced by feeding thiourea at the dose rate 50 mg.kg-1 daily for 28 days to goats. Disposition of lincomycin, after intravenous administration at dose rate 10 mg/kg, was investigated in hypothyroid goats to determine the potential dosage regimen against susceptible microorganisms. Blood samples were collected from 1 min to 24 h of drug administration. The drug was detected in plasma up to 8 h and lincomycin was rapidly distributed from blood to the tissue, as evidenced by the high value of the distribution coefficient (mean ± SEM) 12.3±1.09 h-1. The large Vd (1.78±0.18 L/kg) indicated vast tissue distribution of lincomycin in goats. The elimination half life, AUC and total body clearance were 3.99± 0.25 h, 33.2±1.71 ìg.h/mL and 0.31±0.02 L/h/kg, respectively. Based on results, lincomycin in hypothyroid goats is suggested to be repeated at 12 h interval for organisms sensitive to lincomycin having MIC up to 0.1 µg.ml-1.

Radiation exposure around patients after administration of 123I-MIBG

2002 ◽  
Vol 41 (05) ◽  
pp. 221-223
Author(s):  
S. Ofluoglu ◽  
J. Preitfellner ◽  
B. J. Fueger ◽  
T. Traub ◽  
C. Novotny ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Dose Rate ◽  
Half Life ◽  
Maximum Dose ◽  
Radiation Detectors ◽  
Mibg Scintigraphy ◽  
Dose Limit ◽  
Annual Dose ◽  
Dose Rates ◽  
M 12

SummaryAim: Estimation of the radiation exposure to neighbouring patients, personnel and relatives deriving from patients undergoing 123I-MIBG scintigraphy. Methods: For scintigraphic studies, 16 patients with suspected pheocromocytoma were injected with 340 ± 30 MBq 123I-MIBG. Dose rates were measured at a distance of 0.5 m, 1 m, and 2 m after 10 min, 3 h, 21 h, 45 h, and 68 h using three calibrated portable radiation detectors. The measured values were background corrected. Results: Ten minutes after injection the dose rate was 10.5 µS/h at a distance of 0.5 m, 3.78 µS/h at 1 m, and 0.95 µS/h at 2 m. The effective half-life was estimated to 8.68 ± 0.15 h. The maximum dose in a distance of 1 m for neighbouring patients was 46 µS/h, for personnel in a ward 27 µS/h, and to relatives in a distance of 2 m 12 µS/h. Conclusion: This study demonstrates that the calculated exposure to people around patients after 123I-MIBG injection is well below the maximum permissible annual dose limit of 1 mSv for not professionally exposed persons.

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