Heavy metal pollution of coastal river sediments, north-eastern New South Wales, Australia: lead isotope and chemical evidence

摘要: Heavy metal and metalloid concentrations within stream-estuary sediments (<180-μm size fraction) in north-eastern New South Wales largely represent natural background values. However, element (Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn) of Hunter River the heavily industrialized urbanized Newcastle region exceed upstream values by up to one order magnitude. High have been found Harbour Throsby Creek which drains into light industry areas. Observed Pb enrichments low 208Pb/204Pb, 207Pb/204Pb 206Pb/204Pb ratios are likely caused atmospheric deposition additives from petrol subsequent transport road run-off waters local drainage system. Sediments Richmond lower Manning, Macleay, Clarence, Brunswick Tweed generally display no evidence for anthropogenic heavy contamination Zn). rivers their tributaries possess localized sedimentary traps with elevated (Cu, Lead isotope data indicate that provides a detectable contribution investigated sediments. Such contributions evident at sample sites close sewage outlets vicinity Pacific Highway. In addition, As gradually increase downstream. This geochemical trend may be result mobilization numerous cattle-dip system accumulation downstream river estuary