GcBÜK400 - Cadmium in the topsoil

Description

Cadmium deserves special attention among heavy metals, as its toxicity to animals and humans is significantly greater than that of other heavy metals. As an accumulation poison, it is enriched in the body and can remain there for decades. Due to its chemical affinity to zinc, it occurs almost exclusively with zinc, especially in all zinc-bearing minerals (including zinc diaphragm, galmei) and rocks. The average concentration of Cd in the rocks of the upper continental crust (clearness) is 0.1 mg/kg, soils usually contain 0.50 mg/kg. In contrast to As and other heavy metals (e.g. Cr, Ni), no geochemical specialisation on Cd can be detected in the main Saxon rock types near the surface. The petrogeochemical component is in the range of the Clark value by 0.1 mg/kg. In the ore deposits Cd is mainly bound to the zinc ore of the polymetallic hydrothermal aisles and partly to the skarn deposits and stratigen-stratiform formations (chacogenic component). Since the beginning of industrialization, cadmium has been released into the environment through the emissions of non-ferrous metal smelters, the combustion of coal and petroleum, and more recently through electroplating, waste incineration, fertilizers, sewage sludge and compost. While in the upper soils of North and Central Saxony low grades dominate (Cd-poor periglacian sandy to loamy substrates; Loess), there is a relative accumulation in the weathering soils over solid rocks. A dependence on the clay content is to be found in this respect that the sandy substrates have slightly lower Cd contents compared to loamy substrates. On arable and grassland sites, higher Cd levels are found compared to the forest sites in the topsoil, as the very low pH values under forest lead to Cd mobilization and shift to greater soil depths. Particularly high Cd loads are found in the Freiberg area, which are caused by the geogenous Cd enrichment in the formation of colorful metal-bearing veins, but above all anthropogenic by the smelting of zinc ores. The highest grades are found in the upper soils in the immediate vicinity of the smelter sites and in lower concentrations east of them (in the main wind direction). Other zinc mineralized deposits in the Westerzgebirge and the Erzgebirgsnordrandzone have only slightly elevated grades. The floodplain soils of the Freiberger and the Vereinigte Mulde occupies a special position in the loading with cadmium. Due to the removal of soils with geogenous enrichments in the catchment area and the enormous anthropogenic additional loads caused by the ore processing and the metallurgical industry, high Cd enrichments occur when the river sediments and Schweban parts are deposited in the flood areas. In the floodplain soils of the Elbe and Zwickauer Mulde, on the other hand, significantly lower grades occur. The geogenous and anthropogenic processes lead to area-wide exceedances of the test and action values of the Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV) for cadmium in the Freiberger area and in the floodplain soils of the Freiberger and Vereinigte Mulde.

Resources

Name Format Description Link
0 https://luis.sachsen.de/arcgis/services/boden/gcbuek400/MapServer/WFSServer?request=GetCapabilities&service=WFS
0 https://luis.sachsen.de/arcgis/services/boden/gcbuek400/MapServer/WMSServer?request=GetCapabilities&service=WMS
21 https://luis.sachsen.de/boden/geochemie.html
21 https://luis.sachsen.de/boden/geodatendownload.html
33 https://umwelt.sachsen.de/umwelt/infosysteme/fme/data/boden/gcbuek400/Steckbrief_GCH_Cadmium_2025.pdf
21 https://www.boden.sachsen.de/uebersichtskarten-fuer-schadstoffe-in-boeden-23988.html?_cp=%7B%22accordion-content-23994%22%253A%7B%220%22%253Atrue%7D%252C%22previousOpen%22%253A%7B%22group%22%253A%22accordion-content-23994%22%252C%22idx%22%253A0%7D%7D

Tags

  • chemisches-element
  • geologie
  • boden
  • chemie
  • anorganischer-schadstoff
  • cadmium

Topics

  • REGI
  • ENVI
  • TECH

Categories