Novel environmental monitoring detector for discriminating fallout and airborne radioactivity.

Early warning networks are used for detecting abnormal radioactivity levels in the environment. State-of-the-art networks are equipped with both dose rate detectors and spectrometric stations. Current networks don't automatically discriminate between radioactivity on the ground and in the air. A novel directional sensing gamma radiation detector utilizing a collimated phoswich scintillator was developed. The signals from the two scintillator materials are separated using a pulse shape discrimination. The separated signals are employed to determine the radioactivity concentrations on the ground and in the air assuming specific concentration distributions. Limitations related to imperfect directional sensing and dead time are discussed.

Technical note: Simulation of lung counting applications using Geant4.

A Geant4 simulation package has been developed to investigate and test detector configurations for lung counting applications. The objective of this study was to measure radiation emitted from the human body and to make a qualitative comparison of the results of the simulation with an experiment. Experimental data were measured from a plastic phantom with a set of lungs containing 241Am activity. For comparison, simulations in which 241Am activity was uniformly distributed inside the lungs of the ICRP adult reference computational phantom were made. The attenuation of photons by the chest wall was simulated and from this photopeak efficiency and photon transmission were calculated as a function of photon energy. The transmission of 59.5 keV gamma rays, characteristic of the decay of 241Am, was determined from the computational phantom as a function of the angular position of the detector. It was found that the simulated detector response corresponds well with that from an experiment. The simulated count rate below 100 keV was 10.0(7) % greater compared to the experimental measurement. It was observed that 58.3(4) % of photons are attenuated for energies below 100 keV by the chest wall. In the simulation, the transmission of 59.5 keV gamma rays varied from 13.8(2) % to 38.0(4) % as a function of the angular position of the detector. The results obtained from the simulations show a satisfactory agreement with experimental data and the package can be used in the development of future body counting applications and enables optimization of the detection geometry.

An updated strategic research agenda for the integration of radioecology in the european radiation protection research.

The ALLIANCE Strategic Research Agenda (SRA) for radioecology is a living document that defines a long-term vision (20 years) of the needs for, and implementation of, research in radioecology in Europe. The initial SRA, published in 2012, included consultation with a wide range of stakeholders (Hinton et al., 2013). This revised version is an update of the research strategy for identified research challenges, and includes a strategy to maintain and develop the associated required capacities for workforce (education and training) and research infrastructures and capabilities. Beyond radioecology, this SRA update constitutes a contribution to the implementation of a Joint Roadmap for radiation protection research in Europe (CONCERT, 2019a). This roadmap, established under the H2020 European Joint Programme CONCERT, provides a common and shared vision for radiation protection research, priority areas and strategic objectives for collaboration within a European radiation protection research programme to 2030 and beyond. Considering the advances made since the first SRA, this updated version presents research challenges and priorities including identified scientific issues that, when successfully resolved, have the potential to impact substantially and strengthen the system and/or practice of the overall radiation protection (game changers) in radioecology with regard to their integration into the global vision of European research in radiation protection. An additional aim of this paper is to encourage contribution from research communities, end users, decision makers and other stakeholders in the evaluation, further advancement and accomplishment of the identified priorities.

Occupational exposure to 131I-a case study.

In a laboratory in a company manufacturing radiopharmaceuticals, a laboratory technician was contaminated with I. The employee was preparing I capsules for thyroid carcinoma treatment. The employee was wearing two pairs of protective gloves and, when changing gloves, noticed a rupture in the right inner glove but no visible rupture in the outer glove. Only 3-4 h later, routine monitoring revealed heavy contamination of the back of the right hand. Immediate actions to decontaminate the hand were taken on-site. Stable iodine was not administered. On the next day, besides persisting heavy contamination of the hand, I was also detected in the thyroid gland. Based on original measurements on-site and later follow-up at STUK, including surface contamination measurements and whole body counting, the original I activity on the hand was estimated at 12 MBq and the superficial skin dose at 33 Gy, affecting a skin area of about 10 cm. The thyroid dose was estimated at 430 mGy. Eleven days after the incident, the skin was dry and slightly desquamated. After 15 d, the skin was intact with no desquamation left. No further signs of skin damage have occurred. Cytogenetic analysis of circulating lymphocytes indicated a slight elevation of chromosomal aberrations.

Exogenous contamination of uranium in human scalp hair.

The use of human scalp hair as a bioindicator of occupational or environmental exposure has been the subject of some debate over the years. One problem is how to distinguish internal contamination from external contamination. In this study, possibility that elevated levels of natural uranium in human hair are partly due to the exogenously bound uranium from uranium-rich household water was tested. Hair samples from six adult volunteers were cut and then exposed externally to uranium by using washing water with highly elevated levels of natural uranium. After that, and before making the analysis using inductively coupled plasma mass spectrometry (ICP-MS), the samples were washed using two commonly used washing procedures in order to remove external contamination. No quantitative information was gained in the tests, but it was shown that the use of uranium-rich water when washing hair affects the uranium concentration in hair. Although the samples were cleaned according to widely used washing procedures before the analysis, the uranium concentrations in hair were about three orders of magnitude higher after the tests. The possibility of external contamination should be kept in mind, especially when considering hair as an excretion pathway for estimating internal dose.

Natural variation in 210Po and 210Pb activity concentrations in the urine of Finnish population groups.

A study to determine activity concentrations of (210)Pb and (210)Po in the urine of certain Finnish population groups was conducted, to investigate the variation in natural background level of urinary excretion. The study participants were divided into three groups mainly based on their diet. The first group comprised recreational fishermen and the second group represented people consuming more reindeer meat than an average Finn, while people using drinking water with very high activity concentrations of (210)Po were selected for the third group. The fourth group was a control group. The mean urinary excretion of (210)Po in groups 1 and 2 was 73 and 100 mBq d(-1), respectively. These values were higher than the value of the control group (20 mBq d(-1)) and the mean values reported in the literature. The mean daily urinary excretion of (210)Pb in groups 1 and 2, 70 and 52 mBq d(-1), was also slightly higher than that in the control group (32 mBq d(-1)). In contrast, the excretion rates of both (210)Po and (210)Pb for the members of group 3 were one to two orders of magnitude higher than those reported in the literature. This was clearly due to the elevated levels of natural radionuclides in their drinking water. The present study demonstrates the importance of possessing good knowledge of the background levels, in order to allow the determination of the additional exposure due, for example, to the malevolent use of radiation.

Effective half-lives of 134Cs and 137Cs in reindeer meat and in reindeer herders in Finland after the Chernobyl accident and the ensuing effective radiation doses to humans.

Monitoring of 137Cs in reindeer herders and in reindeer meat in Finnish Lapland began in the early 1960s and has continued until today. The monitoring of 137Cs in reindeer herders and in reindeer meat in the Halla area began after the Chernobyl accident. In this study, reindeer herders together with reindeer meat samples were monitored for gamma-emitting radionuclides from two separate areas in the Finnish reindeer management area, Northern Finland and the Halla area. The effective half-lives determined for 137Cs in reindeer meat were from 3.0 ± 1.7 to 5.1 ± 0.5 y. For 134Cs, the observed effective half-lives in reindeer meat were from 1.3 ± 0.2 to 1.5 ± 0.1 y. The effective half-lives among male and female reindeer herders in Northern Finland were 5.5 ± 1.3 and 4.4 ± 0.9 y, respectively, for the body-burden of 137Cs. In the Halla reindeer herding cooperative, located to the south of Finnish Lapland in the province of Kuusamo, the effective half-lives in the reindeer herders were shorter, about 1-2 y. The 134Cs × 137Cs-1 ratios decreased more rapidly in reindeer meat and also in humans in the Halla area than in Northern Finland. This implies faster removal of Chernobyl-derived cesium from the reindeer-man food chain in the Halla area. The contribution of Chernobyl fallout (percent) in reindeer meat was 70% and 80% in the Paistunturi and Ivalo cooperatives, respectively, and 50% and 80% in the western and eastern part of Halla cooperative, respectively. In humans, the contribution of Chernobyl fallout to 137Cs in whole-body content was 60% in Northern Finland and 80% in the Halla area. The mean committed effective doses of Cs for reindeer herders in Finnish Lapland decreased from 0.36 mSv y-1 in 1987 to 0.053 mSv y-1 in 2005.

A new handbook on triage, monitoring and treatment of people following malevolent use of radiation.

Through the Euratom 6 Framework Programme, the European Commission is co-sponsoring the specific targeted research project "Triage, Monitoring and Treatment-Handbook for management of the public in the event of malevolent use of radiation" (TMT Handbook). The main aim of the project is to produce a handbook for the effective and timely triage, monitoring, and treatment of people exposed to radiation following a malevolent act. The World Health Organization contributed to this project with development of guidelines on medical and public health response. A training course based on the TMT Handbook was developed. It will help to enhance national capacity for planning and response to acts involving the malevolent use of radiation. The course will also provide a platform to identify common challenges and discuss opportunities for harmonizing response strategies throughout the European Union. Focusing on its medical and public health response aspects, this paper introduces the TMT Handbook and its potential applicability not only as practical guidance for end-users but also as a useful tool for education and training.

The mean concentration of uranium in drinking water, urine, and hair of the occupationally unexposed Finnish working population.

Uranium concentrations in the household water, urine, and hair of the occupationally unexposed Finnish working population were determined using inductively coupled plasma mass spectrometry (ICP-MS). The age of the randomly selected participants ranged from 18 to 66 y. The mean concentrations of uranium in water, urine, and hair were 1.25 microg L(-1), 0.016 microg L(-1), and 0.216 microg g(-1), respectively. The mean uranium concentration in hair of the Finnish working population was from 3- to 15-fold higher than the values reported in the literature, while the mean uranium concentration in urine was similar to those measured elsewhere in Europe. The observed large variation in the uranium concentrations in hair and urine can be explained by the variation in the uranium concentration in drinking water. Exceptionally high concentrations have been measured in private drilled wells in the granite areas of Southern Finland.

Internal dose assessment of natural uranium from drinking water based on biokinetic modeling and individual bioassay monitoring: a study of a Finnish family.

Since the later 1960's, a nationwide survey on natural radionuclides in drinking water showed high concentrations of natural uranium (U) in Finland, especially in uraniferous granite areas. In order to assess the radiation dose from the natural uranium to individuals, the concentrations of natural uranium in drinking water of the drilled wells were determined by radiochemical and alpha spectrometric methods. Uranium contents were measured in the urinary samples of five members of a Finnish family by means of inductively coupled plasma-mass spectrometry. Correspondingly, theoretical biokinetic modeling of natural uranium incorporated for the same persons were performed with the aid of follow-up interviews. The ICRP biokinetic compartmental model and the age-dependent transfer rates for uranium were used to model the intake, transfer, distribution, retention, and excretion of (234)U and (238)U, respectively, from the drinking water for each person of the family. The organ absorbed dose, equivalent dose, and effective dose were evaluated for each family member at time intervals using specific effective energy values calculated by the SEECAL program and compared with recommended values. The modeled urinary excretion rates were found to be mostly higher than the measured values by a factor of three. The mean annual effective dose for this family is 8 muSv y(-1). By comparing the measured and calculated data, estimation of retrospective radiation exposure based on biokinetic modeling and bioassay method is enhanced and, vice versa, the biokinetic and dosimetric models are tested and verified.