Accumulation of Radionuclides in Peat Deposits of Bog Ecosystems in the Urals

Studies of the last decades have shown that peat and peat-bogs function as an important factor for environment protection. Due to good take-up and filtering qualities, peat-bog deposits perform to absorb petroleum products, different natural and human-made chemical and radioactive pollutants. Due to low salinity of bog water and turf humic acids, the peat-bed is capable to extract cations of caesium, strontium and other radioactive elements (Kuznetsov et al., 1974; Belkevich and Chistova, 1979; Torf ..., 1988; Jantulen et al., 1991). This report presents results of comparative analyses of the vegetation characteristics, peat-bed stratification, physical and chemical features as related to strontium-90 and caesium-137 contents and distribution throughout areas and depths in three bog ecosystems in the Urals. The Peschany-lake bog (regarded as a control one) is situated in relatively non-polluted zone, Sr and Cs concentrations in the peat layers being due to global fallout. The Olkhovsky bog is situated 60 km eastward from the first one; for about 40 years it was regularly used as a waste ditch accumulating low-activity debalanced waters from the Beloyarsky Atomic Power Plant. The third bog named Maloe Ozero, lies 105 km south-eastward from the Peschany lake, within so-called Eastern-Ural radioactive trace zone (EURT); it was polluted by air radioactive fallout in 1957 (Kyshtym accident) and also by wind-transported radiocontaminated dry mud from the Karachay-lake banks in 1967 and 1970 (Israel et al., 2000).