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This paper summarises the view of the German Commission on Radiological Protection ("Strahlenschutzkommission", SSK) on the rationale behind the currently valid dose limits and dose constraints for workers recommended by the International Commission on Radiological Protection (ICRP). The paper includes a discussion of the reasoning behind current dose limits followed by a discussion of the detriment used by ICRP as a measure for stochastic health effects. Studies on radiation-induced cancer are reviewed because this endpoint represents the most important contribution to detriment. Recent findings on radiation-induced circulatory disease that are currently not included in detriment calculation are also reviewed. It appeared that for detriment calculations the contribution of circulatory diseases plays only a secondary role, although the uncertainties involved in their risk estimates are considerable. These discussions are complemented by a review of the procedures currently in use in Germany, or in discussion elsewhere, to define limits for genotoxic carcinogens. To put these concepts in perspective, actual occupational radiation exposures are exemplified with data from Germany, for the year 2012, and regulations in Germany are compared to the recommendations issued by ICRP. Conclusions include, among others, considerations on radiation protection concepts currently in use and recommendations of the SSK on the limitation of annual effective dose and effective dose cumulated over a whole working life.

The aim of the present study was to determine the internal dose in humans after the ingestion of soil highly contaminated with uranium. Therefore, an in vitro solubility assay was performed to estimate the bioaccessibility of uranium for two types of soil. Based on the results, the corresponding bioavailabilities were assessed by using a recently published method. Finally, these bioavailability data were used together with the biokinetic model of uranium to assess the internal doses for a hypothetical but realistic scenario characterized by a daily ingestion of 10 mg of soil over 1 year. The investigated soil samples were from two former uranium mining sites of Germany with (238)U concentrations of about 460 and 550 mg/kg. For these soils, the bioavailabilities of (238)U were quantified as 0.18 and 0.28 % (geometric mean) with 2.5th percentiles of 0.02 and 0.03 % and 97.5th percentiles of 1.48 and 2.34 %, respectively. The corresponding calculated annual committed effective doses for the assumed scenario were 0.4 and 0.6 µSv (GM) with 2.5th percentiles of 0.2 and 0.3 µSv and 97.5th percentiles of 1.6 and 3.0 µSv, respectively. These annual committed effective doses are similar to those from natural uranium intake by food and drinking water, which is estimated to be 0.5 µSv. Based on the present experimental data and the selected ingestion scenario, the investigated soils-although highly contaminated with uranium-are not expected to pose any major health risk to humans related to radiation.

Here the latest development stages of the HMGU active neutron dosemeter are presented. This work includes the comparison of the dosemeter's response function, calculated with Geant4, and the measurements in monoenergetic neutron fields at the Physikalisch Technische Bundesanstalt in Braunschweig, Germany. These results were used to match the response function and the count-to-dose conversion factors of the dosemeter to the Hp(10) personal dose equivalent., (© The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Two Bonner sphere spectrometers (BSSs) have recently been installed to measure secondary neutrons from cosmic radiation continuously, one at the environmental research station 'Schneefernerhaus' at an altitude of 2650 m in Germany and the other at the Koldewey station close to the North Pole in Ny-Alesund, Spitsbergen. After unfolding, both systems provide neutron fluence energy distributions as a function of time. Based on these distributions and on fluence-to-dose conversion coefficients, mean ambient dose equivalent rate values of 75.0 +/- 2.9 nSv h(-1) and 8.7 +/- 0.6 nSv h(-1) were obtained for October 2008, respectively (quoted uncertainties represent standard deviations of 124 values obtained during the measurement period). Ambient dose equivalent rates measured by means of an extended rem counter at the Schneefernerhaus agree with those based on the BSS neutron energy distributions within 5 %. The ambient dose equivalent rate was also calculated based on simulated FLUKA neutron energy distributions in the atmosphere. Even without detailed modelling of the local environment, an agreement better than 30 % was obtained between the ambient dose equivalent rate based on the FLUKA distributions and those based on the BSS measurements at the Schneefernerhaus, for neutrons above about 20 MeV. This agreement is expected to be even better if the influence of the local environment on the measured neutron fluence energy distribution will be calculated.

Since 1986, the year of the Chernobyl accident, 137Cs body burdens of members of a Bavarian reference group have been measured monthly. These time series were individually analyzed with respect to the long-term component T1 of the biological half-life of 137Cs, assuming a continuous 137Cs intake, which is based on reference data for the food consumption in the Federal Republic of Germany. In 13 individual cases, T1 was additionally deduced after single ingestion of 137Cs. The resulting T1 deduced from continuous and from single intake agreed within about 20%. Using the results of 64 cases, it is shown that there is a dependency of T1 with sex for adults. T1 for children and adults are also significantly different. When combining all data for children, adult females and adult males, significant correlations of T1 with age, 40K and body mass can be found. Since body mass, for example, is a parameter very simple to measure, the given correlations are useful for practical purposes.