Identification of heavy metal sources by multivariable analysis in a typical Mediterranean city (SE Spain)

Problems associated with heavy metal characterization in the majority of sites are often due to multiple sources of pollution. This work presents the results through the use of advanced statistical techniques to identify sources of soil heavy metals in a typical Mediterranean city. The multivariable analysis performed on seven metals identified four sources controlling their variability. Cr, Mn, and Ni contents were associated to soil parent materials; Cd and Pb contents were related to anthropogenic activities, specifically industrial activities and traffic; Cu content is controlled by long-term application of inorganic fertilizers in agricultural areas. Finally, zinc concentration is associated to commercial and outdoor activities in the area. These results were supported by the fact that metals associated to parent material (Cr, Mn, and Ni) were better correlated with soil lithogenic properties, while anthropogenic metals were correlated with more variable soil constituents.