Heavy metal inputs to Mississippi Delta sediments: A historical view

Heavy metal concentrations were determined in suspended particulates, filtered water and sediment collected in the Mississippi river and its marine delta. No cobalt, chromium, copper, iron, manganese or nickel pollution is shown, but there were strong indications of anthropogenic cadmium and lead additions by 200 per cent and 70 per cent respectively over recent decades. River particulate aluminium, cadmium, chromium, iron, lead , and vanadium values are similar to those for delta surface sediments, but cobalt, copper, manganese, nickel, and zinc concentrations are 20-40 per cent higher than those in delta sediments. Trace metal concentrations in filtered Mississippi river water were below the limits for safe drinking water. The abundant river suspended matter and high pH combine to keep dissolved trace metal concentrations low.