• Publikační typ
• abstrakt z konference MeSH

Three experiments were conducted with a volunteer to test the kinetics of the 222Rn exhalation after a short-time exposure to an elevated 222Rn air concentration. Radon concentration in an exhaled air was measured, complemented by whole body counting of 222Rn decay products in a body. Exhaled activities are compared with the prediction of the recent ICRP biokinetic model for radon. While a rapid equilibration of the exhaled radon activity concentration with that in the air inhaled corresponded with the model, the measured 222Rn exhalation rate was significantly less than modelled. Five hours after termination of the inhalation phase, the radon concentration in the exhaled air decreased to levels expected for non-elevated indoor radon activity concentration. Whole body activities of the 222Rn decay products were found higher than expected. Inhalation of the unattached fraction or residual activity of decay products in the air inhaled may be the explanation.

• MeSH
• kinetika MeSH
• lidé MeSH
• radioaktivní látky znečišťující vzduch * analýza   MeSH
• radon * analýza   MeSH
• vydechnutí MeSH
• znečištění vzduchu ve vnitřním prostředí * analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

This work presents an overview of the applications of retrospective dosimetry techniques in case of incorporation of radionuclides. The fact that internal exposures are characterized by a spatially inhomogeneous irradiation of the body, which is potentially prolonged over large periods and variable over time, is particularly problematic for biological and electron paramagnetic resonance (EPR) dosimetry methods when compared with external exposures. The paper gives initially specific information about internal dosimetry methods, the most common cytogenetic techniques used in biological dosimetry and EPR dosimetry applied to tooth enamel. Based on real-case scenarios, dose estimates obtained from bioassay data as well as with biological and/or EPR dosimetry are compared and critically discussed. In most of the scenarios presented, concomitant external exposures were responsible for the greater portion of the received dose. As no assay is available which can discriminate between radiation of different types and different LETs on the basis of the type of damage induced, it is not possible to infer from these studies specific conclusions valid for incorporated radionuclides alone. The biological dosimetry assays and EPR techniques proved to be most applicable in cases when the radionuclides are almost homogeneously distributed in the body. No compelling evidence was obtained in other cases of extremely inhomogeneous distribution. Retrospective dosimetry needs to be optimized and further developed in order to be able to deal with real exposure cases, where a mixture of both external and internal exposures will be encountered most of the times.

• MeSH
• elektronová paramagnetická rezonance MeSH
• ionizující záření * MeSH
• lidé MeSH
• radiometrie metody   MeSH
• radionuklidy farmakokinetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

• Publikační typ
• abstrakt z konference MeSH

The Dukovany nuclear power plant (NPP Dukovany) releases liquid effluents, including HTO, to the Mohelno reservoir, located in a deep valley. Significantly enhanced tritium activities were observed in the form of non-exchangeable organically bound tritium in the surrounding biota which lacks direct contact with the water body. This indicates a tritium uptake by plants from air moisture and haze, which is, besides the uptake by roots from soil, one of the most important mechanisms of tritium transfer from environment to plants. Results of a pilot study based on four sampling campaigns in 2011-2015 are presented and discussed, with the aim to provide new information on tritium transport in the Mohelno reservoir - Jihlava River - plants ecosystems.

• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• jaderné elektrárny MeSH
• monitorování radiace * MeSH
• řeky chemie   MeSH
• tritium analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Rapid measurement techniques are required for a large-scale emergency monitoring of people. In vivo measurement of the bremsstrahlung radiation produced by incorporated pure-beta emitters can offer a rapid technique for the determination of such radionuclides in the human body. This work presents a method for the calibration of spectrometers, based on the use of UPh-02T (so-called IGOR) phantom and specific (90)Sr/(90)Y sources, which can account for recent as well as previous contaminations. The process of the whole- and partial-body counter calibration in combination with application of a Monte Carlo code offers readily extension also to other pure-beta emitters and various exposure scenarios.

• MeSH
• beta částice MeSH
• celotělové počítání přístrojové vybavení   metody   MeSH
• dávka záření MeSH
• elektromagnetické záření MeSH
• fantomy radiodiagnostické MeSH
• kalibrace MeSH
• lidé MeSH
• metoda Monte Carlo MeSH
• monitorování radiace přístrojové vybavení   metody   MeSH
• radiační ochrana přístrojové vybavení   metody   MeSH
• radioizotopy stroncia analýza   MeSH
• radioizotopy ytria analýza   MeSH
• radionuklidy MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

A simple hemispherical phantom has been designed and prepared for the EURADOS intercomparison exercise on (241)Am activity determination in the skull (2011-13). The phantom consists of three parts that substitute bone and soft tissues. (241)Am is deposited on the surfaces of the bone-substituting part. The design and assumed composition of phantom parts are discussed. A preparation of the voxel representation of the phantom is described. The spectrum of a real measurement of the physical phantom agrees well with the simulation. The physical phantom, and its voxel representation, is provided to the participants of the intercomparison exercise.

• MeSH
• americium analýza   MeSH
• design vybavení MeSH
• fantomy radiodiagnostické MeSH
• fotony MeSH
• kalibrace MeSH
• kosti a kostní tkáň MeSH
• lebka účinky záření   MeSH
• metoda Monte Carlo MeSH
• monitorování radiace metody   MeSH
• počítačová rentgenová tomografie MeSH
• polyurethany chemie   MeSH
• radiometrie metody   normy   MeSH
• reprodukovatelnost výsledků MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

A pilot study aimed on possible occurrence of elevated activity of non-exchangable organically bound tritium (NE-OBT) in biota was performed. The first results showed a significant surplus of NE-OBT activity in biota of the valley of Mohelno reservoir and Jihlava river. The liquid releases of HTO from the nuclear power plant Dukovany is the source of tritium in this area. This area can be a source of various types of natural samples for future studies of tritium pathways.

• MeSH
• jaderné elektrárny MeSH
• lidé MeSH
• monitorování radiace přístrojové vybavení   metody   MeSH
• pilotní projekty MeSH
• radioaktivní látky znečišťující vodu analýza   MeSH
• radioaktivní znečišťující látky analýza   metabolismus   MeSH
• řeky chemie   MeSH
• rostliny metabolismus   MeSH
• scintilace - počítání přístrojové vybavení   metody   MeSH
• společenstvo MeSH
• tritium analýza   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Urinary excretion of uranium of 40 uranium miners was determined by the high-resolution inductively coupled mass spectrometry method. The concentration of uranium in the urine of the miners was converted to daily excretion of (238)U either under the assumption that the daily urinary excretion is 1.6 l or daily urinary excretion of creatinine is 1.7 g and compared with the excretion of (238)U calculated with a biokinetic model. Input data to the excretion model were derived from personal three- component ALGADE dosemeters, using the component for the estimation of inhalation of long-lived alpha radionuclides. Experimentally found contents of uranium in the urine of uranium miners are generally lower than the modelled ones, which means that the dosimetric approach is conservative. The uncertainty of inhalation intakes, derived from the measurements of filters from personal dosemeters, and the uncertainty of the concentration of uranium in the urine are discussed.

• MeSH
• alfa částice * MeSH
• dávka záření MeSH
• hmotnostní spektrometrie MeSH
• lidé MeSH
• monitorování radiace * MeSH
• pracovní expozice škodlivé účinky   MeSH
• uran moč   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

An internal contamination with (241)Am was detected in a worker during a routine monitoring of workers from a company producing Am sources for smoke detectors and Am-Be neutron sources. During the 4-year period after the exposure, the number of urine and faecal samples from the worker were analysed; in vivo measurements were also performed. Specific values for absorption parameters of the human respiratory tract model and particle transport values were applied to improve the model fit to the measurement data. A good agreement of the bioassay data with the so-modified model predictions was obtained.

• MeSH
• americium farmakokinetika   moč   MeSH
• biotest MeSH
• celotělové počítání MeSH
• dospělí MeSH
• hodnocení rizik MeSH
• kosti a kostní tkáň účinky záření   MeSH
• lidé MeSH
• obsah radioaktivních látek v organizmu MeSH
• plíce účinky záření   MeSH
• počítačová simulace MeSH
• pracovní expozice analýza   MeSH
• relativní biologická účinnost MeSH
• tkáňová distribuce MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH