Lead content and isotopic composition in submound and recent soils of the Volga upland

Literature data on the historical reconstructions of the atmospheric lead deposition in Europe and the isotopic composition of the ores that are potential sources of the anthropogenic lead in the atmospheric deposition in the lower Volga steppes during different time periods have been compiled. The effect of the increasing anthropogenic lead deposition recorded since the Bronze Age on the level of soil contamination has been investigated. For the first time paleosol buried under a burial mound of the Bronze Age has been used as a reference point to assess of the current contamination level. The contents and isotopic compositions of the mobile and total lead have been determined in submound paleosols of different ages and their recent remote and roadside analogues. An increase in the content and fraction of the mobile lead and a shift of its isotopic composition toward less radiogenic values (typical for lead from the recent anthropogenic sources) has been revealed when going from a Bronze-Age paleosol to a recent soil. In the Bronze-Age soil, the isotopic composition of the mobile lead is inherited from the parent rock to a greater extent than in the modern soils, where the lead is enriched with the less radiogenic component. The effect of the anthropogenic component is traced in the analysis of the mobile lead, but it is barely visible for the total lead. An exception is provided by the recent roadside soils characterized by increased contents and the significantly less radiogenic isotopic composition of the mobile and total lead

Chemical Constituents in the Surface Snow in Mizuho Plateau

Chemical features and profiles of the ice sheet in Mizuho Plateau have been revealed by means of newly developed analytical techniques such as atomic absorption spectrophotometry, neutron activation method and isotope dilution mass spectrometry. The chemical concentration is as low as ppb level even for the major components, Na, K, Mg and Ca, and its distribution is homogeneous in the surface sheet but shows much vertical complexity. Silicate dusts which functioned as the condensation nuclei for the formation of snow crystal in the upper atmosphere and which were captured by snow fall process are poor, while sea salts account for more than 90per cent of the total weight of components. Annual accumulation of chemical components, μg/(cm)^2,is 0.1 for silicate dusts and 0.40,0.03,0.1 and 0.06 for Na, K, Mg and Ca originated from the latter source. Annual accumulation of Hg and Pb is at the level of 0.1 and 1.5 ng/(cm)^2 at the present time while 0.02 and 0.3ng/(cm)^2 in ancient times