Age-dependent congener proﬁles of polychlorinated dibenzo-p-dioxins and dibenzofurans in the general population of Taiwan Jing-Fang Hsu a , Yu-Chen Chang a , Pao-Chi Liao a,b, * a Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 704, Taiwan b Sustainable Environment Research Center, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan article info Article history: Received 3 March 2010 Received in revised form 14 June 2010 Accepted 18 July 2010 Available online 24 August 2010 Keywords: PCDD/Fs Age Gender Congener proﬁle Multivariate analysis General population abstract A congener proﬁle of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) could provide valu- able information for identifying possible sources of exposure to these compounds. The purpose of this study is to identify factors associated with PCDD/F congener proﬁles in the general population of Taiwan. Serum samples from 251 subjects of the general population in Taiwan were collected, and the levels of 17 2,3,7,8-chlorinated substituted PCDD/Fs were measured. The relationships between PCDD/F congener proﬁles and demographic parameters were evaluated using a multivariate analysis of variance method (MANOVA). Of the ﬁve demographic factors investigated, age was found to have the greatest impact on PCDD/F congener proﬁles. The PCDD/F congener pattern for the group I subjects (aged 18–29) was sig- niﬁcantly different from those for the other three older age groups (p < 0.001), and 12 congeners contrib- uted to the effects (difference index: 71%). In addition, the group I subjects did not exhibit trends parallel to those of the other groups in the relationship between age and PCDD/F levels. Age was associated with PCDD/F levels and congener proﬁles in the general population of Taiwan and the young subjects (aged 18–29) was quite different from the other older subjects that could be inﬂuenced by the individual dif- ferences in pharmacokinetics and/or background exposure from dietary sources. We conclude that inves- tigators must consider subjects’ age and other underlying factors that could inﬂuence PCDD/F congener proﬁles in humans when identifying exposure sources. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlori- nated dibenzofurans (PCDFs) are a group of structurally related chemicals. Humans are always exposed to mixtures of PCDD/Fs from various media (such as food, air, and soil) in the environment (Papke, 1998). It has been postulated that the media from different environments may contain mixtures of PCDD/Fs with different congener proﬁles (Gilpin et al., 2003). In principle, such source – and/or medium-speciﬁc proﬁles could provide information useful for identifying the source of these compounds, including environ- mental pollution, as well as human exposure to it (DeCaprio et al., 2005; Chen et al., 2010). However, linking contaminated sources with human exposure by using PCDD/F congener proﬁles poses certain problems. The main issue is that the congener pro- ﬁles of these compounds in humans are strongly inﬂuenced by the individual’s absorption, metabolism, distribution, and elimina- tion of these compounds. Many factors could inﬂuence the phar- macokinetics of chemicals in an individual, such as ethnicity, gender, age, genetics, and the induction of enzymes from exposure to other environmental chemicals or to drug usage (Alvarez et al., 1999; Price et al., 2003; Parkinson et al., 2004). To efﬁciently assist in exposure source identiﬁcation for human PCDD/F exposure, a more complete characterization of congener proﬁles of PCDD/F in humans is crucial. A multivariate statistical method, multivariate analysis of variance (MANOVA), has been used to resolve this issue and deal with the differentiated effects of gender and dietary hab- its in PCB congener proﬁles in human blood (Schaeffer et al., 2006). Taiwan is an urbanized and industrialized island with 20 muni- cipal waste incinerators and many factories with combustive pro- cesses. A survey on PCDD/F/PCB levels in the general population of Taiwan was carried out during 2001–2006. The TEQ levels of PCDD/F/PCBs in this population associated with age, gender, resi- dential regions, smoking status, and dietary status was reported (Hsu et al., 2009). In this report, a multivariate statistical method, 0045-6535/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2010.07.044 Abbreviations: ANOVA, analysis of variance; ALTEP Taiwan, Analytical Labora- tory for Trace Environmental Pollutants at National Cheng Kung University in Taiwan; HRGC–HRMS, high-resolution gas chromatography–high-resolution mass spectrometry; MANOVA, multivariate analysis of variance; PCBs, polychlorinated biphenyls; PCDDs, polychlorinated dibenzo-p-dioxins; PCDFs, polychlorinated dibenzofurans; TEQ, oxic equivalent; WHO-TEFs, World Health Organization toxic equivalency factors. * Corresponding author at: Tel.: +886 6 2353535x5566; fax: +886 6 3028095. E-mail address: liaopc@mail.ncku.edu.tw (P.-C. Liao). Chemosphere 81 (2010) 469–477 Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere