Herngren, L; Goonetilleke, A; Ayoko, GA
Road-deposited sediments were analysed for heavy metal concentrations at threeifferent landuses (residential,ndustrial, commercial)n Queensland State, Australia. The sediments were collected using aomestic vacuum cleaner which was proven to be highly efficientn collecting sub-micron particles. Five particle sizes were analysed separately for eight heavy metal elements (Zn, Fe, Pb, Cd, Cu, Cr, Al and Mn). At all sites, the maximum concentrationf the heavy metalsccurredn the 0.45-75 microm particle size range, which conventional street cleaning serviceso not remove efficiently. Multicriteriaecision making methods (MCDM), PROMETHEE and GAIA, were employedn theata analysis. PROMETHEE, a non-parametric ranking analysis procedure, was used to rank the metal contentsf the sediments sampled at each site. The most polluted site and particle size range were thendustrial site and the 0.45-75 microm range, respectively. Although thendustrial siteisplayed the highest metal concentrations, the highest heavy metal loading coincided with the highest sediment load, whichccurred at the commercial site. GAIA, a special formf principal component analysis, was applied toetermine correlations between the heavy metals and particle size ranges and also to assess possible correlation with totalrganic carbon (TOC). The GAIA-planes revealed thatrrespectivef the site, mostf the heavy metals are adsorbed to sediments below 150 microm. A weak correlation was found between Zn, Mn and TOC at the commercial site. This could lead to higher bioavailabilityf these metals through complexation reactions with therganic speciesn the sediments.