Int. J. Environ. Res. Public Health 2009, 6 195 to total doses made by external dose have shown a decreasing trend, with the most recent study assessing a more comparable contribution to dose from external and internal sources than thought previously. A slight increase of external exposures witnessed to residents of Muslyumovo and Brodokalmak in recent years is probably due to increased use of the sanitary zone: today, teenagers receive the highest external doses because they use the floodplain more. However, adult residents, especially those born before 1951, have received the highest accumulated effective doses. It is therefore clear that restrictions on usage of the sanitary zones and floodplain would reduce the current doses to riverside residents. Concentrations of 90Sr and 137Cs in privately produced agricultural food products around the Muslyumovo and Brodokalmak areas have been reported as being quite low for the most important products (milk, potatoes, vegetables, meat), though average intakes of radionuclides are obviously in excess of unaffected populations due to the local contamination. Average effective internal doses are higher in Muslyumovo compared to Brodokalmak with some studies suggesting that frequent use of the floodplain for food and fodder production increase the intake and dose estimates by about a factor three. An increase in the risk of developing solid carcinoma or leukemia has been demonstrated for the affected populations though it is important to note that residents in the area who were not exposed to the highest contamination period (due to age or migration) are believed to experience an approximate two orders of magnitude lower risk for developing radiation induced cancer than those who lived in the area during the period of intensive discharges. References 1. 2. 3. 4. 5. Malyshev, S.V.; Vakulovsky, S.M.; Drozhko, E.G.; Romanov, G.N.; Glagolenko, Y.V.; Mokrov, Yu.G.; Westerlund, E.A.; Amundsen I.; Strand, P.; Salbu, B.; Oughton, D.H.; Christensen, G.C.; Bergan, T.S. in Joint Norwegian-Russian Expert Group (JNREG) Sources contributing to radioactive contamination of the Techa River and the area surrounding the "Mayak" production association, Urals, Russia. In Programme of the Joint Norwegian-Russian Investigations of possible impacts of the Mayak PA activities on radioactive contamination of the Barents and Kara Seas. Norwegian Radiation Protection Authority: Østerås, Norway, 1997. Christensen, G.C.; Romanov, G.N.; Strand, P.; Salbu, B.; Malyshev, S.V.; Bergan T.D.; Oughton, D.; Drozkho, E.G.; Glagolenko, Y.V.; Amundsen, I.; Rudjord, A.L.; Bjerk, T.O.; Lind, B. Radioactive contamination in the environment of the nuclear enterprise `Mayak` PA. Results from the joint Russian-Norwegian field work in 1994. Sci. Tot. Env. 1997, 202, 237-248. Trapeznikov, A.V.; Pozolotina, V.N.; Chebotina, M. Ya.; Chukanov, V.N.; Trapeznikova, V.N.; Kulikov, N.V.; Nielsen, S.P.; Aarkrog, A. Radioactive contamination of the Techa River, The Urals. Health Phys. 1993, 65, 481-488. Cochran, T.B.; Standish Norris, R.; Suokko, K.L. Radioactive contamination at Chelyabinsk-65, Russia. Annu. Rev. Energy Environ. 1993, 18, 507-528. Bradley, D.J.; Jenquin, U.P. Radioactive inventories and sources for contamination of the Kara Sea by fluvial transport. Office of Naval Research Report, Contract N00014-94-1-0054. Pacific Northwest Laboratory: Richmond, Washington, U.S., 1995.