Fossil fuels, trace element analysis

The view at Cadmium changed with time starting from a valuable resource and ending up as a toxic element with a limited number of applications not substituted by alternative products. The decontamination of the technosphere works to a certain extent. Due to the character of Cd as trace contamination of phosphate fertilizers and of Zn ores and fossil fuels, there is no final solution for the environmental contamination. Due to the restrictions issued in many countries, there is reason to fear that Cd could end up in unknown material streams. From an analysis of the refining of Zn ores in 2002, it has been concluded that about one quarter of Cd generated as by-product ( 7,000-8,000 Mg) could not be found either in the products analyzed or in the emissions from the process [27]. 

Based on this analysis, the major sources of trace metals in PM2.5 at the urban sites included in this study are, natural dust resuspension processes (indicated by th presence of mineral elements such as Fe and Mn), industrial emissions (Cu, As, Cd, Pb, Mo and Sn), fossil fuel refining and/or burning processes (Ni, V, Se) and traffic related emissions (Ba, Sr Sb, Zn). The mineral component comprises 55-65% of the trace metal concentrations in PM2.5 in urban areas and above 70% at rural sites. The contribution of the anthropogenic sources depends on the human... 

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