Determining depleted uranium (DU) contamination in soils and salt marsh sediments in the vicinity of DU munitions testing sites in SW Scotland and NW England, UK

Abstract

first of all, such changes manifest themselves in the extent of the impact of operating plants upon the environment and the air basin. This atmo-geochemical research was performed through studying natural depositing medium snow cover, as the composition of its insoluble fraction is identical to that of solid constituent of air pollutants. The solid phase was analyzed through the method of quantitative spectral analysis for a wide set of heavy metals. Based on the data on heavy metal contents in separate samples, specialized geochemical maps of the city's territory were produced applying GIS ArcView 3.2 a. These initial data allow to calculate in-day dust load per square kilometer -38.3 kg/sq, km*day, respectively, for the whole of the city's territory (225 sq. kin) -8.6 tons. Data on element contents in dust allow to calculate the load of separate elements throughout the city landscape; so in-day load of Zn is 2.3 kg, Cu 1.1 kg. The determined contents of heavy metals are standardized by the element background and the following ranked geochemical series of heavy metal contents in ambient dust throughout the city was made up: Mo-Ag-Sn-Zn-Ni-Cu-Cr-Pb. The maps clearly reflect the morphology and extent of pollution zones and the structure of pollution. To characterize complex pollution, we have calculated a Summary Index of Pollution (SIP) that represents the sum of heavy metal contents in samples standardized by the background. For the city's territory, the summary index varies from 44 to 129. The research results show that dust in ambient air is simultaneously contaminated with several heavy metals. Comparing data on SIP with sanitary-standardized indices for heavy metal contents in dust allows to attribute pollution of the city's air basin with heavy metals to middle-level one. SIP for heavy metals in dust can be used as a geoindicator to characterize the intensity of man-made geochemical stream in the atmosphere.