Effective dose assessment for workers in caves in the Czech Republic: experiments with passive radon detectors

The new RAMARN system for radon volume activity measurement was developed in 2003 and has been in use since then. RAMARN system consists of a plastic chamber that is conically cylindrical in shape and about 0.5 l in volume; a bare Kodak LR 115 is located on the bottom of this diffusion chamber. The size was chosen to avoid the influence of deposited decay products of radon. Kodak has a spectrometric character-the tracks are visualized only for alphas with energies between 1 and 3 MeV that touch the foil; thus the effective volume has a lens shape. The response therefore corresponds to diffused radon and half of (218)Po born by radon gas decay. The experiments described below were conducted as one part of a routine methodology control, focused on classifying worker irradiation from natural ionizing radiation sources in show caves and in caves used for speleotherapy.     

Radon in soil gas--investigation and data standardisation at radon reference sites, Czech Republic

Radon risk mapping at building sites in the Czech Republic indicate an advisable level of protection of buildings against the penetration of radon from the geological basement. Various techniques and instruments are used for the measurement of radon in soil gas. A national radon chamber and three radon reference sites in Central Bohemia enable radon data standardisation. Tests of field radon measurements and the reported radon activity concentration in soil gas at the reference sites are based on comparisons with other organisations and with a database of reference site measurements. The radon reference sites have been used for various investigations of radon in soil gas during the period 2000-07.     

Radon exposure assessment for underground workers: a case of Seoul Subway Police officers in Korea

The objective of this study is the systematic and individual assessment of the annual effective dose due to inhaled radon for the Seoul Subway Police officers, Korea. The annual average radon concentrations were found to be in the range of 18.9-114 Bq·m(-3) in their workplaces. The total annual effective doses which may likely to be received on duty were assessed to be in the range of 0.41-1.64 mSv·y(-1). These were well below the recommended action level 10 mSv·y(-1) by ICRP. However, the effective doses were higher than subway station staff in Seoul, Korea.     

Patenting propensity in the Czech Republic

We have compared patenting propensity in the Czech Republic with eight EU countries: Germany, Austria, Hungary, Poland, Finland, Belgium, Ireland and Greece. In comparison based on the EPO and USPTO patents listed per million inhabitants, the Czech Republic ranks rather low. The Czech Republic also generated fewer patents per R&D employee than most other countries. The time series data have shown a decrease of number of Czech patents after 1990 with some revival after 1996. As our analysis indicated, the decrease was partially caused by dissolution or transformation of major patent generators, but the most important cause may lie in a little interest of local enterprises.     

Fullerene Research in the Czech Republic

Abstract

Fullerene Science and Technology, both the field and the journal, have observed considerable progress during the last few years. The field has continued to mature as witnessed by the many new and interesting results published in thousands of journal articles (1-3) and in a multitude of books and conference proceedings. The recognition of fullerene sciences as a self-containing field of research has been culminating in the awarding of the 1996 Chemistry Nobel Prize to Professors Robert S. Curl, Harold W. Kroto, and Richard E. Smailey.     

Radon progeny in Egyptian underground phosphate mines

In addition to the workers in uranium mines, the staff of other underground mines, such as workers in underground phosphate mines, can be exposed to 222Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure of the workers at those sites. A filter method was used to measure individual radon progeny concentrations (218Po, 214Pb and 214Po). The reported mean values of radon progeny concentrations exceed the action levels which are recommended by ICRP 65 (1993). Based on the measured individual radon progeny concentrations (218Po, 214Pb and 214Po) in these mines, the annual effective dose for the workers has been calculated using the lung dose model of ICRP 66 (1994). According to the obtained results, some countermeasures were recommended in this study to minimise these exposure levels.     

Radon in context of natural radiation exposure: the Czech experience

Radon issue should be seen in the context of other human exposures and harms. The range of doses from the internal (inhalation and ingestion) and external exposure pathways is presented. Indoor radon regulation is compared with regulation of other natural exposures.     

Patient skin dosimetry in interventional cardiology in the Czech Republic

In this study, skin dosimetry of patients undergoing interventional cardiology procedures is presented. Three hospitals were included. Two methods were used for skin dosimetry--radiochromic dosimetry films and reconstruction of skin dose distribution based on examination protocol. Maximum skin doses (MSD) obtained from both methods were compared for 175 patients. For patients for whom the film MSD was >1 Gy, the reconstruction MSD differed from the film MSD in the range of ± 50 % for 83 % of patients. For remaining patients, the difference was higher and it was caused by longer fluoroscopy time. For 59 patients for whom the cumulative dose was known, the cumulative dose was compared with the film MSD. Skin dosimetry with radiochromic films is more accurate than the reconstruction method, but films do not include X-ray fields from lateral projections whilest reconstructions do.     

Radon time-series analysis in the underground low-level laboratory in Belgrade, Serbia

Measurements of radon concentration in the underground low-level laboratory in Belgrade, Serbia with a discrete sampling (T=2 h) have been performed. From July 2008 to July 2010, the time-series analysis was carried out. Also, the simultaneous measurements of meteorological parameters (temperature, atmospheric pressure and relative humidity) in the laboratory were done. The simultaneous monitoring of these parameters shows the correlation between temporal variations of radon concentration and meteorological parameters. Also, the radon time-series analysis has been used to study the possible correlation between the anomalous behaviour of the radon concentration and the local seismicity.     

An objective methodology for dose distribution analysis

The advent of single aliquot optically stimulated luminescence (OSL) techniques along with parallel equipment advances have made it possible and practical to obtain statistically meaningful quantities of equivalent dose (De) data from individual samples. Now that hundreds of dose determinations can be made for one sample De distributions may be scrutinised, leading to the problem of how to make unbiased comparisons among distributions, and how to decide objectively which dose is representative of the age of the deposit. In this paper, an objective analytical method is presented for treating dose distributions, including a mathematically rigorous means of determining a representative equivalent dose and a statistical definition of its corresponding uncertainty. This analytical method has been applied to Holocene aeolian and fluvial quartz sands from Central Oklahoma. The results are compared to equivalent doses determined via other proposed analytical procedures.     

Evaluation of occupational exposures to natural radiation in the Czech Republic

The Czech approach to limit the occupational exposures to natural radiation is based on the rules given by the Atomic Act and by the Decree of the State Office for Nuclear Safety (SONS) on radiation protection. Workplaces with potential risk of increased exposure to natural sources are specified explicitly. A new method to perform the above-mentioned measurements and to determine the effective doses of workers was proposed in 2005 and accepted by the SONS in 2007. The first experience illustrates its applicability.     

Radon dynamics and reduction in an underground mine in Brazil. Implications for workers' exposure

This work was aimed at studying the behaviour of 222Rn in an experimental underground copper mine in Brazil with a single entrance. The 222Rn concentrations, meaured by using a dynamic radon measuring technique. varied between 30.5 Bq.m(-3), during ventilated conditions applied to the mine galleries, and 19.4 x 10(3) Bq.(-3) for non-ventilated conditions and when operational mining activities were conducted inside. High radon concentration surges were observed after blasting and drilling activities. In the cases of inadequate ventilation, it was estimated that workers could be subjected to exposures as high as 10 microSv.h(-1), only due to 222Rn and its short-lived progeny. The results show the importance of real-time measurements to evaluate radon dynamics during mining operations.     

Cost-effectiveness of countermeasures against radon in the Czech Republic: preliminary report

The cost-effectiveness of remedial and preventive countermeasuresagainst indoor radon in the frame of the Czech Radon Programmeis preliminarily estimated, resulting in 72 700 CZK and 194000 CZK per y of life gained by remediation and prevention,respectively, (exchange rate 28 CZK/EUR).     

PRDC--a software package for personnel radiation dose calculation

To determine effective dose, we usually need to use a very complicated human body model and a sophisticated computer code to transport radiations in the body model and surrounding medium, which is not very easy to practicing health physicists in the field. This study develops and tests a software package, called PRDC (Personnel Radiation Dose Calculation), which calculates effective dose and radiation doses to various organs/tissues and personal dosemeters based on a series of interpolations.     

Estimation of the uncertainty in internal dose calculation for two contamination cases

The assessment of internal dose is subject to a large uncertainty due to the limits of measuring technique and to the assumptions made by the expert. Here, we propose an approach to report the confidence interval associated with the evaluated dose. The sources of uncertainties considered so far include the date of intake, the physico-chemical characteristics of the radioactive material, the counting error and the stochastic variability of excretion. Three successive levels of approximation are suggested, depending on the expected dose, for which increasingly realistic parameter values should be sought and applied. Finally, the results of a Monte Carlo dose calculation are presented in the form of a statistical distribution of possible dose values. This approach has been applied to two cases of uranium and caesium exposure.     

Bibliometric evaluation of the FP-5 and FP-6 results in the Czech Republic

Our study evaluates results and impacts of the Framework Programs (FP) 5 and 6 in the Czech Republic. Publications resulting from the FP projects had 42% higher mean citation rate and 77% more EU-25 collaborations than the Czech standards. Teams participating in the FP are better-than-average, because citation rate of all their papers is 21% higher than the Czech standards. The most striking finding is the marked influence of FP on research direction. After the project start, the participating teams published papers in ten new fields in which they did not publish before the project. In 45 other fields, more than 200% increase of papers was observed.