Uptake of Cs and Cs by Ceratophyllum demersum L. under field and greenhouse conditions.

The phytoremediation abilities of Hornwort (Ceratophyllum demersum L.) were tested under greenhouse and field conditions. Plants were exposed for 8, 16, and 24 days (greenhouse with stable isotope Cs), 8 days (field with Cs), and 8 days (climabox with radioactive isotope Cs).

PUMA - pooled uranium miners analysis: cohort profile.

Objectives: Epidemiological studies of underground miners have provided clear evidence that inhalation of radon decay products causes lung cancer. Moreover, these studies have served as a quantitative basis for estimation of radon-associated excess lung cancer risk. However, questions remain regarding the effects of exposure to the low levels of radon decay products typically encountered in contemporary occupational and environmental settings on the risk of lung cancer and other diseases, and on the modifiers of these associations.

PSEUDO-3D IMRT VERIFICATION WITH EBT3 RADIOCHROMIC FILM.

This work proposes a new method for pseudo-3D verification of intensity-modulated radiation therapy (IMRT) dose distributions. Unlike commercial solutions, it uses measured doses only for gamma evaluation. Its resolution is far better than with electronic detectors within the measured plane and comparable in other directions.

OPTIMIZATION OF THE RADIOACTIVE AEROSOL SAMPLING AND MEASURING PROCEDURE WITH RESPECT TO RADON CONCENTRATION IN THE AIR.

High-volume aerosol samplers combined with laboratory analysis using high-resolution gamma ray spectrometry allow determining artificial radionuclides in the atmosphere at sub μBq/m3 levels. A major drawback of this procedure is a significant delay of the analysis result after any potential radioactive contamination deposition on the aerosol filter. Within the scope of the HAMRAD project, an autonomous device was developed in order to increase the sampling and measuring frequency.

RESULTS OF CZECH NATIONAL STUDY OF RADIATION EXPOSURE FROM RADIOTHERAPY OF NON-MALIGNANT DISEASES, IN PARTICULAR OF HEEL SPURS.

About 26 000 patients are treated per year with radiotherapy for non-malignant diseases in the Czech Republic. Approximately 75% of them are treated on X-ray therapy units and most of these patients undergo radiotherapy of heel spurs. The evaluation of radiation exposure of these patients was based on measured organ doses and on data from clinical practice.

ACTIVITY OF 137CS IN HUMAN BODY OF INHABITANTS OF THE CZECH REPUBLIC.

The time course of 137Cs activity in general population of the Czech Republic has been systematically followed since the Chernobyl accident in 1986. Either whole body counting or the determination of 137Cs content in 24-hour urine samples were used as a method of determination of body activity. Environmental and effective half-lives were calculated from the data.

POSTAL TLD AUDIT OF HETEROGENEITY CORRECTIONS IN RADIOTHERAPY IN THE CZECH REPUBLIC.

In the Czech Republic, a more advanced version of postal audit in radiotherapy (RT) is available. It covers dose measurements with thermoluminescent dosemeters (TLD) in more complex conditions of irradiation, when dose distribution is affected by heterogeneities in the irradiated volume. Relative deviation between doses measured with TLDs and doses stated by RT centre should not exceed 3%.

CONTINUOUS RADON-IN-WATER MONITORING-COMPARISON OF METHODS UNDER LABORATORY CONDITIONS AND RESULTS OF IN SITU MEASUREMENTS.

The extraction of dissolved radon from water to gas is the most common way to measure radon concentration in water continuously. The response delay of continuous radon-in-water detection system (continuous monitor + equilibrator) is influenced by the response time of the continuous monitor and a rate of an establishment of equilibrium in the equilibrator (exchanger unit). Two types of equilibrators were used in performed experiments to compare the response time of various detection systems-RAD AQUA that uses water spraying and equilibrator with ACCUREL® PP membrane that enables radon diffusion.

SUPPORT TO CITIZEN RADIATION MONITORING OF RADIOACTIVITY IN THE CZECH REPUBLIC-PROJECT RAMESIS.

Project 'RAMESIS', solved by SURO+UTEF+NUVIA, is aimed at the improvement of population safety through supporting Citizen Monitoring in Czechia. Radiation monitoring system at the level of institutions, schools and citizens will be developed and implemented, covering equipment for both fixed-site and mobile monitoring using simple-designed and easy-to-operate detectors, enabling their usage by public and mass-production at acceptable price. The instrumentation includes central application for reception, storage, administration and publication of monitoring results analyzed and presented on web-portal, tools for user's local online and offline data visualization on a map background, and web portal providing training and informational materials for understanding radiation problems.

RAMESIS PROJECT: COLLABORATION WITH SCHOOLS AND INSTITUTIONS ON THE BUILDING OF A CITIZEN MONITORING NETWORK.

In a radiation emergency situation, including its post-emergency recovery phase, substantial needs for radiation measurements can be expected. In such situations, responsible authorities might not be able to satisfy all requirements for measurement. Therefore, involvement of local communities is desirable.

RESPONSE OF THE CZECH RMN NETWORK TO THUNDERSTORM ACTIVITY.

Thunderstorm ground enhancement (TGE) is a phenomenon that enhances radiation background on the ground related to thunderstorm activity and charge structure of the thundercloud. On the other hand, the rise of gamma background is connected with precipitation by the washout of radon progeny from the atmosphere. In our analysis, we examined known enhancements of gamma background, previously attributed solely to radon progeny, using data from the Czech Radiation Monitoring Network (RMN) to investigate the enhancements with respect to thunderstorms and TGE phenomena.

MEAN VALUE OF LET FOR ONCOGENIC EFFECTS OF RADON AND ITS PROGENY.

The topic of the article is to define the average value of linear energy transfer (LET) for carcinogenic effects of radon progeny. The microdosimetric model of boundary specific energy is used. It follows that the effect at high LET should decrease approximately with the third power of LET.

LUNG REGENERATION IN ABSTAINING SMOKERS.

Smoking modifies morphological and physiological parameters of the lungs. Due to the irritation of airways, the natural self-cleaning ability of the lungs is impaired. The mucus accumulates in the airways and various infections develop, leading to chronic bronchitis.

THE USE OF THE EXRADIN W1 PLASTIC SCINTILLATOR FOR MEASUREMENTS IN EXTERNAL RADIOTHERAPY.

The Exradin W1 plastic scintillator (Standard Imaging) was examined for measurement suitability in high-energy photon beams, high-energy electron beams and tomotherapy in terms of dose to water for reference fields. For photon beams, pulse repetition rate dependence, calibration stability, noise from the photodiode enclosure, detector motion during treatment, output factors, off-axis doses and percentage depth doses were tested. For electron and tomotherapy beams, energy non-dependence was verified.

DETERMINATION OF TOLERANCE LEVELS IN RADIOTHERAPY DOSIMETRY BASED ON STATISTICAL INTERFERENCE.

The most important dosimetry quantity that is determined at radiotherapy centers is the absorbed dose to water for external beams. Fixed tolerances for absorbed doses measured under reference conditions with an ionization chamber for high-energy photon and electron beams are usually 2 and 3%, respectively, regardless of uncertainties of the input variables and other conditions during evaluation. In reality, this agreement should be evaluated considering the uncertainties of the input variables because they affect the size of the random deviations of the measurements from their true values.

RETROSPECTIVE DOSE RECONSTRUCTION WITH MOBILE PHONES AND CHIP CARDS.

Mobile phones and common chip cards are very widespread items that almost everyone owns. They contain some radiation-sensitive materials that can be used for dosimetry based on stimulated luminescence. We investigated and compared reproducibility, dose response and fading of luminescence signal for the particular materials.

COMPARISON OF DIFFERENT TECHNIQUES FOR EVALUATION OF DOSE DISTRIBUTIONS IN RADIOTHERAPY USING RADIOCHROMIC EBT3 FILMS.

In radiotherapy, radiochromic films can be used for verification of delivery of dose distributions calculated by treatment planning systems. The main objective of this work was to compare three different techniques for evaluation of dose distributions for prostate cancer treatment plans using radiochromic EBT3 films. These techniques are: red channel evaluation taking into account only a response of irradiated film (R), red channel evaluation taking into account a response of unirradiated and irradiated film (Rcor) and multichannel evaluation in FilmQA software (RGB).

ASSOCIATION OF 210Po CONTENT IN URINE WITH CONCENTRATION OF 222Rn IN DWELLINGS.

Effect of indoor radon concentrations higher than 500 Bq m-3 in dwellings on excretion of 210Po was studied in 28 volunteers. The study was further augmented by following eight individuals from the group for 5 months at 1-month intervals. Association between 222Rn concentration in homes and 210Po excretion was found when the dataset containing values of the studied 27 subjects was combined with data on 40 Prague inhabitants from the previous study.

EXPOSURE OF THE BIOGAS STATION OPERATORS WORKING WITH CONTAMINATED BIOMASS.

The article deals with evaluation of irradiation of an operator of a 1 MW biogas station (BGS), processing silage plant biomass contaminated by 137Cs and 134Cs. External irradiation and internal irradiation by the means of aerosol particles inhalation were considered. For calculation of the external irradiation, a BGS model was created in the MCNP.

EMERGENCY PREPAREDNESS OF GAMMA SPECTROMETRY LABORATORIES.

Currently, the territorial Radiation Monitoring Network (RMN) of the Czech Republic consists of seven laboratories equipped with gamma spectrometry High Purity Germanium (HPGe) detectors. From 2007 to 2018, five emergency exercises were carried out to test the sample throughput of these facilities and their staff. The main objective was to identify weaknesses and problem areas in the whole process from the moment of obtaining the samples to logging the results into the central RMN database.

NEUTRON DOSE ASSESSMENT USING SAMPLES OF HUMAN BLOOD AND HAIR.

The unique feature of nuclear accidents with neutron exposure is the induced radioactivity in body tissues. For dosimetry purposes, the most important stable isotopes occurring in human body, which can be activated by neutrons, are 23 Na and 32 S. The respective activation reactions are as follows:23Na(n,γ)24Na and32S(n,p)32P.

Testing the methodology for a dosimetric end-to-end audit of IMRT/VMAT: results of IAEA multicentre and national studies.

Within an International Atomic Energy Agency (IAEA) co-ordinated research project (CRP), a remote end-to-end dosimetric quality audit for intensity modulated radiation therapy (IMRT)/ volumetric arc therapy (VMAT) was developed to verify the radiotherapy chain including imaging, treatment planning and dose delivery. The methodology as well as the results obtained in a multicentre pilot study and national trial runs conducted in close cooperation with dosimetry audit networks (DANs) of IAEA Member States are presented. A solid polystyrene phantom containing a dosimetry insert with an irregular solid water planning target volume (PTV) and organ at risk (OAR) was designed for this audit.

Radon as a Tracer of Lung Changes Induced by Smoking.

After smoking, exposure to radon and its progeny is the second leading cause of lung cancer. The probability of inducing lung carcinomas by inhaled radon progeny depends on the deposited radiation dose, and is significantly affected by physiological and morphometric changes induced by smoking. Due to irritation of the airways, the inhalation of cigarette smoke leads to the hyperproduction of mucus.

Airborne concentrations and chemical considerations of radioactive ruthenium from an undeclared major nuclear release in 2017.

In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (Ru). The range of concentrations varied from some tenths of µBq·m to more than 150 mBq·m The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location.