Heavy metals in soils near a steel‐making industry: A case study in a complex valley situation in Italy

Abstract

Mn, Zn, Ni, Cu, Pb and Cr from a steel industry were studied in soils from an alpine valley near Turin (NW Italy). Dusts fell onto the agricultural lands in the valley floor as first demonstrated by a lichens analysis. Soil analysis showed that total metals were often very high without differences between topsoils and deeper layers, except Pb. In order to assess the risky zones a geostatistical approach was considered, lacking the parameters needed for modeling and because of the complex terrain. A spatial dependence for several metals was detected, but isarithmic maps from Kriging showed that the fallout of these single elements was not uniform. From a multivariate analysis a linear combination of total metals was computed: its score, used as a global index, well described the spatial distribution of the fallout. An effect of the high mountain walls on the fallout peaks was then suggested.

Key words:

• Soil pollution
• Heavy metals
• Geostatistics
• Steel plant
• Complex terrain