Long-term monitoring of metal pollution in sediments from the estuary of the Nerbioi-Ibaizabal River (2005–2010)

摘要: Abstract This work aims to investigate the spatial and temporal distribution of trace metals in sediment samples taken from Nerbioi-Ibaizabal River estuary (Bilbao, Basque Country) over course a long-term surveillance monitoring programme 2005 2010. Sediment Quality Guidelines (SQGs) geoaccumulation indexes ( I geo ) were used assess environmental risk posed by metal content sediment. was collected at eight different sites every three months period investigation. A total 14 elements (Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn, V Zn) selected concentration each measured all samples. Additionally, conductivity, pH carbonate, organic carbon fulvic humic acids also those sampling campaigns March 2006 October 2008. The most systematically decreased There are still some points (those located surroundings Gobela Galindo tributaries), however, where concentrations Pb Zn significantly higher than background values estimated for area. According mean Effects Range Median quotients (mERMqs) calculated these sites, sediments may pose toxicological threat living organisms. Metal inner is low. Specific point sources estuary, together with contamination diffuse origin, probably responsible this situation.