The data treasure-trove in the southern urals

Sometimes Dr Peter Jacob’s job is like a detective’s. How much radiation was a worker exposed to fifty years ago in the Russian plutonium factory Mayak? How did the system of dams on the Techa river work, into which the radioactive waste used to be released? Jacob coordinates the project on radiation risk research in the Southern Urals (SOUL) which involves fourteen Russian and European research institutions. The researchers aim to analyse the unique data from the medical records of the Mayak workers and the people living on the river.

Both groups were exposed to radiation in the late 1940s and early 1950s, the period when plutonium production for nuclear weapons was being expanded in the so-called secret cities. Peter Jacob says that many of the estimates about the amount of radiation exposure the people suffered have large uncertainties. His laboratory in the Helmholtz Zentrum München is therefore examining items such as bricks from buildings on the banks of the Techa and affected people’s teeth. The results indicate a relatively low exposure for the local inhabitants – comparable with that of more exposed workers in Germany or patients who have had several whole body CT scans. For exposure of this type, it was previously thought that the cancer risk per dose was less than for nuclear bomb survivors. However, initial analyses of the Techa residents do not confirm this. The cancer risk per radiation dose appears to be just as high for them.

The Mayak workers, on the other hand, were exposed to relatively high levels of radiation. Jacob explains that through the study of Mayak workers, the lung cancer risk resulting from plutonium exposures could be established for the first time. Plutonium causes about ten times as many cases of lung cancer as the same dose of gamma radiation. The researchers are now eagerly anticipating the analysis of cardiovascular disease among the Mayak workers. The indications are that radiation protection must take not only the risk of cancer but also of cardiovascular disease into account.