Evaluation of age, gender and regional concentration differences for dioxin-like chemicals in the Australian population F.A. Harden a, * , L.M.L. Toms a , O. Paepke b , J.J. Ryan c , J.F. Mu ¨ ller a a National Research Centre for Environmental Toxicology, The University of Queensland, Brisbane, Australia b ERGO Research, Hamburg, D22305, Germany c Health Canada, Bureau Chemical Safety, Ottawa, Ont., Canada K1A 0L2 Accepted 26 May 2006 Available online 26 January 2007 Abstract The results of this study provide a measure of the levels of dioxin-like compounds (polychlorinated dibenzo-p-dioxins, polychlori- nated dibenzofurans and polychlorinated biphenyls) in pooled blood serum collected throughout Australia in 2003. De-identified sam- ples selected from surplus pathology samples were stratified on the basis of gender, region and age. In total 9090 samples were collected and analysed as 96 pools. Dioxin-like chemicals were detected in all strata. The mean and median levels expressed as TEQ values for all pooled samples were 10.9 ± 1.0 pg TEQ g 1 lipid and 8.3 pg TEQ g 1 lipid. For males and females the mean levels were 10.4 ± 0.6 pg TEQ g 1 lipid and 11.5 ± 1.5 pg TEQ g 1 lipid, respectively. A direct relationship of increasing dioxin-like chemical levels with increasing age was observed and could be described by the follow- ing equation: Levels in blood expressed as pg TEQ g 1 lipid ¼ 3:3exp 0:0251age ðr 2 ¼ 0:87Þ: No significant differences were observed in the levels of dioxin-like chemicals in samples collected from males and females. In addition, the levels of dioxin-like chemicals across the five regions were similar within each age range. In summary, the levels of dioxin-like chemicals in the Australian population are low compared to international levels and are similar across all regions of Australia within each designated age range. The levels of these chemicals increase with age and can be estimated if the age of an individual is known. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Polychlorinated dibenzo-p-dioxins; Polychlorinated dibenzofurans; Polychlorinated biphenyls; Human blood serum; Australia 1. Introduction The polychlorinated dibenzo-p-dioxins (PCDDs), poly- chlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) constitute families of persistent organic pollutants (POPs) that are present in both biological and environmental samples. These compounds are produced during a variety of chemical processes and also during waste incineration. Australia is a large island continent with low population and industry density. Notably, the population base and industry is concentrated along the south eastern coastline. Recent studies by the authors on breast milk, indicate that the levels of PCDDs, PCDFs and PCBs in Australian women are low in comparison to international levels (Van Leeuwen and Malish, 2002; Harden et al., 2004) 0045-6535/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2006.05.146 * Corresponding author. Tel.: +617 32749016; fax: +617 32749003. E-mail address: f.harden@uq.edu.au (F.A. Harden). www.elsevier.com/locate/chemosphere Chemosphere 67 (2007) S318–S324