Dioxin-related compounds in breast milk of women from Vietnamese e-waste recycling sites: Levels, toxic equivalents and relevance of non-dietary exposure Nguyen Minh Tue a,b , Kana Katsura a , Go Suzuki c , Le Huu Tuyen a,b , Takumi Takasuga d , Shin Takahashi a,e,n , Pham Hung Viet b , Shinsuke Tanabe a a Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan b Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam c Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan d Shimadzu Techno-Research, Inc., Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto, Japan e Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan article info Article history: Received 17 January 2014 Received in revised form 28 April 2014 Accepted 29 April 2014 Keywords: CALUX Breast milk Brominated dioxin E-waste Vietnam abstract Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and poly- brominated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and PBDD/Fs), human exposure to the latter has not been studied in details. This study investigated the accumulation levels and profiles of dioxin-related compounds (DRCs) in breast milk samples from women living in two Vietnamese EWRSs and estimated the intake contribution from e-waste-related exposure. Screening results using Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX) showed higher dioxin-like (DL) activities in samples from the EWRS Bui Dau than in those from the EWRS Trang Minh and a reference site (2.3–10 vs 1.7–4.8 and 0.60–5.7 pg CALUX-TEQ/g lipid, n ¼10, 6 and 9, respectively). Chemical analysis results of selected samples show that the WHO-TEQ levels of PCDD/Fs, DL-PCBs and PBDD/Fs in EWRS samples were not significantly higher than in those from the reference site (0.22–7.4 vs 1.1–3.0 pg/g lipid) and within the Vietnamese background range, but women involved in recycling accumulated higher concentrations of PCDFs (13–15 vs 2.3–8.8 pg/g lipid) and PBDFs (1.1–1.5 vs o1.1 pg/g lipid). By comparing the DRC profile in milk of these women with the reported profile in house dust from the same site, dust ingestion was estimated to contribute most of the intake for tetraBDF, 37 per cent to 55 per cent for penta– octaCDFs, but less than twenty per cent for PCDDs and DL-PCBs, and 26 per cent for total WHO-TEQs. The DL activities in some EWRS milk samples were not fully explained by chemical data, suggesting contribution from unidentified compounds. The estimated WHO-TEQ intake doses for breastfed infants (1.3–33 pg/kg/d) mostly exceeded the tolerable value, especially for those living in the EWRSs; and unidentified DRCs might increase further the dioxin-related health risk. & 2014 Elsevier Inc. All rights reserved. 1. Introduction Rapid growth in the amount of waste electrical and electronic equipment (WEEE), also known as e-waste, and continuing infor- mal recycling activities of these materials pose serious risks of environmental pollution and human health impacts (Zhang et al., 2012). Primitive e-waste processing methods such as acid- stripping and open burning of wires for metal retrieval, heating circuit boards for dismantling, and chipping and melting of plastics not only facilitate the release of hazardous chemicals contained in e-waste (e.g. toxic metals, brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs), etc.), but also generate dioxin- related compounds (DRCs)—including polychlorinated dibenzo-p- dioxins/dibenzofurans (PCDD/Fs), their brominated (PBDD/Fs) and mixed brominated/chlorinated homologues (PXDD/Fs)—as sec- ondary pollutants (Tue et al., 2013b). The occurrence of PBDD/Fs in EWRSs has been associated with high content of BFRs, especially polybrominated diphenyl ethers (PBDEs), in e-waste plastics (Ma et al., 2009; Tue et al., 2010). Technical PBDE formulations have been found to contain PBDFs as impurities (Hanari et al., 2006). PBDD/Fs can be generated from these precursors not only during waste incineration (Duan et al., 2011; Weber and Kuch, 2003), as is the case with the more well known PCDD/Fs, but also through degradation at o300 1C(Weber and Kuch, 2003) or under natural light (Kajiwara et al., 2008). Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/ecoenv Ecotoxicology and Environmental Safety http://dx.doi.org/10.1016/j.ecoenv.2014.04.046 0147-6513/& 2014 Elsevier Inc. All rights reserved. n Corresponding author at: Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. Fax: þ81 89 946 9980. E-mail address: shint@agr.ehime-u.ac.jp (S. Takahashi). Ecotoxicology and Environmental Safety 106 (2014) 220–225