Heavy metals and trace element concentrations in intertidal soils of four estuaries of SW Iberian Peninsula

8 pages, 2 figures, 1 table, 29 references.Soils from four estuaries of SW Iberian Peninsula, affected by anthropogenic influence (urban, industrial and agricultural activities), were analyzed for the occurrence of a variety of metals and trace elements including Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S and Zn. The soils presented very high levels of salinity (high concentrations of Na, K and Mg), organic matter and, consequently, of C and N concentrations. In contrast, very low values of CaCO3,Ca and Pwere found. In addition, it should be highlighted that in certain localities (Piedras 1 and 2 and Guadiana in Huelva, Spain, and Ria Formosa, Faro, Portugal) the concentrations of Pb, S and Zn were extremely high, reaching levels of pollution.We thank the Spanish Science and Technology and Environmental Ministries for their support (projects 04212007 and PCI2006-A7-0641, respectively).Peer reviewe