title: Dioxin-related compounds in breast milk of women from Vietnamese e-waste recycling sites: levels, toxic equivalents and relevance of non-dietary exposure.
abstract: Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and polybrominated 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=10, 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 <1.1 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.
authors.affiliation: Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam.
authors.forename: Nguyen Minh
authors.initials: NM
authors.lastname: Tue
authors.affiliation: Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Katsura
authors.affiliation: Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.affiliation: Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam.
authors.forename: Le Huu
authors.initials: le H
authors.lastname: Tuyen
authors.affiliation: Shimadzu Techno-Research, Inc., Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Takasuga
authors.affiliation: Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan; Center of Advanced Technology for the Environment, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. Electronic address: shint@agr.ehime-u.ac.jp.
authors.forename: Shin
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi, Vietnam.
authors.forename: Pham Hung
authors.initials: PH
authors.lastname: Viet
authors.affiliation: Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Tanabe
mesh_terms: D004147:Dioxins / Q000032:analysis* / Q000633:toxicity; D004391:Dust / Q000032:analysis; D059029:Electronic Waste; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity; D005260:Female; D006801:Humans; D008895:Milk, Human / Q000737:chemistry*; D059027:Recycling; D018570:Risk Assessment; D014744:Vietnam
chemical_list: D004147:Dioxins; D004391:Dust; D004785:Environmental Pollutants
keywords: Breast milk; Brominated dioxin; CALUX; E-waste; Vietnam