PAHs,PCDD/Fs,PCBsandHCBinleavesfromBrisbane, Australia JochenF.M uller a, * ,DarrylW.Hawker b ,MichaelS.McLachlan c,1 , DesW.Connell b a National Research Center for Environmental Toxicology, University of Queensland, 39 Kessels Road, Coopers Plains, 4108 Qld, Australia b Faculty of Environmental Sciences, Grith University, Nathan, 4111 Qld, Australia c Ecological Chemistry and Geochemistry, University of Bayreuth, Bayreuth Germany Abstract The concentrations of SOCs in leaves of an evergreen Australian native tree Melaleuca leucadendra) and grass collectedinBrisbane,Australiaweredetermined.TheconcentrationsofPCDD/FsandPAHsintheleaftissuewere comparable to those reported for urbanised areas in other industrialised countries. A distinct dierence in the com- poundpro®lesbetweentheleavesofthetwospecieswasobserved,withhigherconcentrationsofthelowermolecular massPAHsandPCDD/FsandlowerconcentrationsofthehighermolecularmassPAHsandPCDD/Fsinthe Mel- aleuca leavesrelativetothegrassleaves.Theinterspeciesdierencesareexplainedonthebasisofthelargersizeofthe lipophiliccompartmentforcompoundswithlow K OA )andthelowerratioofsurfaceareatovolumeinthe Melaleuca leaves. Ó 2001ElsevierScienceLtd.Allrightsreserved. Keywords: PAHs;PCDD/Fs;Leaves;Compoundpro®les;Mechanisms 1. Introduction Many semivolatile organic compounds SOCs) in- cludinganumberofthepolychlorinateddibenzodioxins and dibenzofurans PCDD/Fs), polychlorinated biphe- nyls PCBs), and polycyclic aromatic hydrocarbons PAHs)aretoxic,persistent,andhydrophobic,andhave been shown to accumulate in biota Mackay, 1982; HawkerandConnell,1991).AlthoughSOCsaretaken upbyhumansviainhalation,ithasbeenshownthatthis does not make a major contribution to overall uptake Standley and Hites, 1991) except in atypical exposure situations such as the uptake of carcinogenic PAHs throughsmokingMenzieetal.,1992).Food,especially products which originate from animals, is usually the main source of exposure for SOCs such as PAHs e.g. Menzie et al., 1992) and PCDD/Fs e.g. Henry et al., 1992; Theelen et al., 1993). Uptake of persistent atmo- spheric SOCs in vegetation is the ®rst step of a multi- step pathway through the food chain resulting in the contamination of animals and humans McLachlan, 1997). Many plants have a relatively large surface area coveredwithwaxesthatfacilitatestheaccumulationof hydrophobicchemicalsMcCradyetal.,1990;Riederer, 1995).Theuseofplantsas`passivesamplers'oforganic compounds in the atmosphere has been suggested by many authors e.g. Grimmer and Hildebrandt, 1965; Erikssonetal.,1989;Franzaringetal.,1992;Kylinetal., 1994; Lead et al., 1996). Plants have been used as biomonitorstoevaluatetheextentandsourceofpollu- tionMeredithandHites,1987;Safeetal.,1992)aswell Chemosphere432001)507±515 * Correspondingauthor.Tel.:+61-7-3274-9147;fax:+61-7- 32749003. E-mail address: j.mueller@mailbox.uq.edu.au J.F. M ul ler). 1 Presentaddress:BalticSeaResearchInstitutePostfach30 1161,D-18112Rostock-Warnem unde,Germany. 0045-6535/01/$-seefrontmatter Ó 2001ElsevierScienceLtd.Allrightsreserved. PII:S0045-653500)00402-1