Few studies have investigated the human exposure to the ensemble of dioxin-related compounds (DRCs) released from uncontrolled e-waste recycling, especially from a toxic effect standpoint. This study evaluated the TCDD toxic equivalents (TEQs) in persistent extracts of settled house dust from two Vietnamese e-waste recycling sites (EWRSs) using the Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX), combined with chemical analysis of PCDD/Fs, DL-PCBs, PBDD/Fs, and monobromo PCDD/Fs to determine their TEQ contribution. The CALUX-TEQ levels in house dust ranged from 370 to 1000 pg g^-1 in the EWRSs, approximately 3.5-fold higher than in the urban control site. In EWRS house dust, the concentrations of the unregulated PBDFs were 7.7-63 ng g^-1, an order of magnitude higher than those of regulated DRCs (PCDD/Fs and DL-PCBs), and PBDFs were also principal CALUX-TEQ contributors (4.2-22%), comparable to PCDD/Fs (8.1-29%). The CALUX-TEQ contribution of DRCs varied, possibly depending on thermal processing activities (higher PCDD/F-TEQs) and PBDE content in the waste (higher PBDF-TEQs). However, the percentage of unknown dioxin-like activities was high in all dust samples, indicating large contribution from unidentified DRCs and/or synergy among contaminants. Estimates of TEQ intake from dust ingestion suggest that children in the EWRSs may be adversely affected by DRCs from dust. © 2010 American Chemical Society.

Tue N.M., Suzuki G., Takahashi S., Isobe T., Trang P.T.K., Viet P.H., Tanabe S.

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Từ khóa : Chemically activated LUciferase gene expressions; Control sites; Dioxin-like PCBs; Dl-PCBs; Dust ingestion; Dust samples; e-Waste; House dust; Human exposures; Order of magnitude; PCDD/Fs; Related compounds; Thermal processing; Toxic effect; Toxic Equivalents TEQ; Chemical analysis; Gene expression; Houses; Polychlorinated biphenyls; Recycling; Toxic materials; Wastes; Dust; dioxin; polybrominated dibenzofuran; polychlorinated biphenyl; polychlorinated dibenzodioxin; chemical analysis; gene expression; health risk; industrial emission; ingestion rate; particulate matter; PCB; PCDD; pollution exposure; recycling; toxicity; article; chemical analysis; dioxin responsive chemically activated luciferase gene expression assay; genetic analysis; house dust; recycling; thermal analysis; urban area; Viet Nam; Viet Nam