AN URBAN SOIL STUDY - HEAVY-METALS IN GLEBE, AUSTRALIA

This study investigated the occurrence of Pb, Zn, Cu, and Cd in the to psoil of an inner-city suburb of Sydney, Australia. The total heavy me tal concentrations in the topsoil of Glebe were determined along with their spatial distribution. These concentrations were compared with en vironmental investigation limits. Stratified random sampling was condu cted within 1-ha square areas taking a samples at 1 m separation from each stratum as a means to investigating spatial variation. Total meta l concentrations were determined on an aqua regia extract analysed usi ng atomic absorption spectroscopy. Fifty percent of total Pb, Zn, and Cu concentrations and 2.5% of Cd concentrations were above the ANZECC and NH&MRC (Australia & New Zealand Environment Conservation Council a nd National Health & Medical Research Council) guidelines of 300, 200, 60, and 3 mg/kg, respectively. Some spatial clustering was evident an d a geostatistical analysis showed some large high-risk areas. Fuzzy c lustering showed 5 groups of increasing contamination. Soil disturbanc e and distance from road explained 24% of the variation in total Pb co ncentration, 15% in total Zn and Cu concentrations, and 13% in total C d concentration.