TRACE-METAL FLUXES TO LAKE-SEDIMENTS IN SOUTH-EASTERN AUSTRALIA

Trace metal fluxes have been determined for two lakes in south-eastern Australia. Lakes in the Melbourne metropolitan area and in a remote region of the Australian Alps were examined. Historic fluxes were calculated from the combination of trace metal concentrations and sedimentation rates. The trace metal concentrations of Pb, Cu and Zn were determined by conventional atomic absorption spectrophotometric methods, and the rates of sedimentation by Pb-210 dating. In the last 80 years the flux of Zn has increased 42-fold and Cu 30-fold in the Melbourne area. The flux of stable lead has increased 90-fold in the urban environment and 35-fold in the remote location. At the Melbourne site the average Pb flux over recent years has been 230 mg m-2 year-1.