Nuclear and related analytical techniques used to study the anthropogenic impact on the Sister River in the vicinity of the town of Klin (Moscow Region, Russia)

The ecological fate of small rivers, tributaries of the Volga River, is of great concern in the national program of the Russian Federation 'Restoration of the Volga River'. The results on the elaborated hydrochemical and saprobiological water examination of the Sister River are reported along with the results on the multielement chemical analysis of surface sediments in the catchment of the town of Klin (Moscow Region) known for its numerous industrial and chemical enterprises with heavy contaminant inputs. Epithermal neutron activation analysis was used to study heavy metals and other toxic elements in bottom sediments. A total of 42 elements including Pb, Cu, Cd and Hg were determined by polarography (method of inverse voltamperometry). Metal/Al rations which express the relative mobility of the elements follow the sequence: Fe > Mg > K > Na > Ca >> Zr > Mn > Zn = Sr > Cr > V > Ni = As > Co. Elevated concentrations of Cd, Pb, Zn and Cu in the bottom sediments of the Sister River reinforced us to determine their chemical forms using fractionation scheme. Cadmium is mostly associated with carbonate content and thus has a possibility of becoming readily bioavailable. Its toxicity and bioavailability poses a serious problem to ecosystem. Copper and zinc besides having less environmental risk are present in forms in which they cannot be easily leached out. Accumulation of toxic metals, arsenic and oil products are of potential hazard for the secondary pollution of the surface waters. It is shown that the main sources of pollution in the vicinity of the town of Klin are the domestic sewage waters and sewage waters from the chemical complex 'Klin-Fiber' producing synthetic materials. The extremes of the distribution patterns of pollutants in the bottom sediments and water are to be found approximately 50 km down the stream from the discharge sources. The second source of geochemical anomaly is located upstream of the Sister River, before the town of Klin