Evaluation of dioxin-like activities in settled house dust from Vietnamese E-waste recycling sites: relevance of polychlorinated/brominated dibenzo-p-dioxin/furans and dioxin-like PCBs.
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.
Center for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.
Nguyen M
NM
Tue
Go
G
Suzuki
Shin
S
Takahashi
Tomohiko
T
Isobe
Pham T K
PT
Trang
Pham H
PH
Viet
Shinsuke
S
Tanabe
D001572:Benzofurans / Q000032:analysis* / Q000633:toxicity; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins / Q000032:analysis / Q000633:toxicity; D004391:Dust / Q000032:analysis; D059029:Electronic Waste / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity; D006801:Humans; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000633:toxicity; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000633:toxicity; D014744:Vietnam; D018505:Waste Management / Q000379:methods
D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins; D004391:Dust; D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls