The purpose of the expedition is to study the environmental situation and to compile a map of the most contaminated reservoirs in the region. The map will help create a list of contingency measures for emergency situations. There are no chemical plants in western Siberia, nevertheless radionuclides can be found in fish bones as well as muscle tissue of animals. Reports by medics also sound the alarm as the level of cancer diseases in Ugra (the new name of Khanty-Mansi Autonomous Area) is 50 per cent higher than Russia’s average. Scientists do not rule out the possibility that (contaminated) water is the source of the problem. At present they are set to find out whether radionuclides leak into reservoirs from marshes in the water-meadows of the Techa River. Radionuclides appeared there about 50 years ago after an accident at one of the Urals chemical plants. The consequences of the five nuclear blasts that were carried out in the Ugra marshes in the Soviet era have not yet been studied. The radionuclides could not disappear by themselves as plutonium’s half-life is thousands of years, but radionuclides are actively moving around. Scientists say that a high level of them settle in water-meadows. Such large-scale research into Siberian rivers is being held for the first time.