Concentration and distribution of twelve metals in Central Catalonia surface soils

A total of 27 surface soil samples were collected to investigate the concentration (aqua regia extractable) and spatial distribution of five major elements (Al, Ba, Fe, Mn and Sr) and seven trace elements (Cd, Cr, Cu, Ni, Pb, V and Zn) in Central Catalonia (NE Spain). The median concentrations (mg kg−1) were: Ba 227, Cd 0.32, Cr 25, Cu 20.3, Ni 23.6, Pb 19.7, Sr 73.7, V 50.2, Zn 72.2, Al 22214, Fe 21754 and Mn 463. The highest median of Ba, Cr, Cu, Ni, Sr, V, Al, Fe and Mn are in soils formed from lutites and those of Cd, Pb and Zn to soils derived from limestones. The soils formed from sandstones have the lowest median values of the studied metals. The spatial distributions of Cr and Ni are similar. The distribution patterns of Cd, Cr, V and Zn have in common higher values in NW, N and NE areas; but Zn, moreover, has high concentration also in the eastern area. In general, the metal higher values occur in the NW, N and NE. Some of them, such Cd, Cr, Ni, Pb and Mn also show significant values in southern-center area. Barium, Cu and Mn show as well higher values in the SE corner of the studied region.

Research Highlights
► Concentrations of Ba, Cd, Cr, Cu, Ni, Pb, Sr, V, Zn, Al, Fe and Mn in top soils of Central Catalonia (NE Spain).
► Clay and OM contents, EC and pH were related to metal concentrations using correlation and factorial analysis.
► Relationship between these twelve metals of tops soils and their parent rocks.
► The pattern distribution of these twelve metals in top soils of Central Catalonia (NE Spain).