Dose limits for occupational exposure to ionising radiation and genotoxic carcinogens: a German perspective.

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.

Assessment of mRNA and microRNA Stabilization in Peripheral Human Blood for Multicenter Studies and Biobanks.

In this study we evaluate the suitability of two methods of RNA conservation in blood samples, PAXgene and RNAlater, in combination with variable shipping conditions for their application in multicenter studies and biobanking. RNA yield, integrity, and purity as well as levels of selected mRNA and microRNA species were analyzed in peripheral human blood samples stabilized by PAXgene or RNAlater and shipped on dry ice or at ambient temperatures from the study centers to the central analysis laboratory. Both examined systems were clearly appropriate for RNA stabilization in human blood independently of the shipping conditions. The isolated RNA is characterized by good quantity and quality and well suited for downstream applications like quantitative RT-PCR analysis of mRNA and microRNA. Superior yield and integrity values were received using RNAlater. It would be reasonable to consider the production and approval of blood collection tubes prefilled with RNAlater to facilitate the use of this excellent RNA stabilization system in large studies.

Leukemia and exposure to ionizing radiation among German uranium miners.

BACKGROUND: It is well known that uranium miners are at an increased risk of lung cancer. Whether they also have an increased risk for other cancer sites remains under discussion. The aim of this study was to examine the leukemia risk among miners. METHODS: An individually matched case-control study of former uranium miners in East Germany was conducted with 377 cases and 980 controls. RESULTS: Using conditional logistic regression models, a dose-response relationship between leukemia risk and radon progeny could not be confirmed. Yet, a significantly elevated risk is seen in the category > or = 400 mSv when combining gamma-radiation and long-lived radionuclides. CONCLUSIONS: The results suggest that an elevated risk for leukemia is restricted to employees with a very long occupational career in underground uranium mining or uranium processing. Moreover, the study does not support the hypothesis of an association between exposure to short-lived radon progeny and leukemia risk.

Uranium mining in Germany: incidence of occupational diseases 1946-1999.

OBJECTIVES: In East Germany, uranium mining was performed on a large scale for approximately 45 years (1946-1990). In particular, the poor working conditions during the post-war years until 1955 led to a high level of occupational diseases. The present study gives an overview of the occurrence of occupational diseases during the mining period as well as after uranium mining was stopped in 1990. METHODS: The number of occupational diseases which occurred during the mining period was calculated from the files of the former Wismut SDAG. Although exposure to uranium ceased after 1990, new cases of occupational diseases were recognized after that date. These were recorded by the German Federation Of Institutions For Statutory Accident Insurance And Prevention (HVBG). RESULTS AND CONCLUSIONS: Today, more than 35,000 cases of occupational diseases are known, and many more are expected. About two-thirds of them are lung diseases: 16,376 cases of silicosis/silicotuberculosis and 7,695 cases of bronchial carcinomas. The increase in the number of recognized occupational diseases is shown and discussed against the background of changes in criteria for recognition and in working conditions as well as the duration of the latency period.