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Information regarding the contamination of brominated flame retardants (BFRs) in lake sediments from Vietnam and Southeast Asia is still very limited. To fill such knowledge gaps, surface sediment samples from five urban lakes in Hanoi, Vietnam, were analyzed for polybrominated diphenyl ethers (PBDEs) and some other BFRs. Concentrations of total PBDEs ranged from 1.1 to 26 (median 6.6) ng/g dry weight with the most predominant congeners as BDE-209 (62 ± 17%), BDE-99 (10 ± 8%), and BDE-47 (6 ± 5%). Concentrations of other BFRs decreased in the order: decabromodiphenyl ethane (DBDPE) > 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) > hexabromobiphenyl (BB-153) > pentabromoethylbenzene (PBEB), which were about one to two orders of magnitude lower than PBDEs. BDE-209 and DBDPE were highly correlated (Pearson's r = 0.879; p < 0.01), suggesting their similar applications and/or environmental fate. Potential sources of BFRs in lake sediments are estimated to be wastewater discharge, riverine inflow, and atmospheric deposition. [ABSTRACT FROM AUTHOR]

Settled dust samples from Vietnamese end-of-life vehicle (ELV) processing, urban, and rural areas were analyzed for polybrominated diphenyl ethers (PBDEs) and other current-use brominated flame retardants (BFRs). PBDE levels found in dust samples collected from ELV workshops (median 390; range 120–520 ng/g) and nearby living areas (110; 36–650 ng/g) were generally higher than those in common house dust (25–170 ng/g). BDE-209 was the most predominant congener detected in almost all the samples, indicating extensive application of products containing deca-BDE mixtures. The dust samples from ELV workplaces showed a more abundance of lower brominated congeners (e.g., tetra- to hexa-BDEs) that may originate from car interior materials treated by penta-BDE formulations. Concentrations of other BFRs decreased in the order urban > rural > ELV dust, reflecting the current use of these compounds in new consumer products. Decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were the major alternative BFRs. Daily intake doses and hazard indexes of PBDEs and some other BFRs through dust ingestion were estimated and showed acceptable levels of risk. However, more comprehensive risk assessment considering multiple exposure pathways should be performed, especially for ELV workers and children in the ELV processing and urban areas. [ABSTRACT FROM AUTHOR]

Information about the co-occurrence of halogenated flame retardants (HFRs) and organophosphate esters (OPEs) in the environment of informal waste processing areas is still limited, especially in emerging and developing countries. In this study, OPEs and HFRs including polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and chlorinated flame retardants (CFRs) were determined in settled dust from Vietnamese e-waste recycling (WR) and vehicle processing (VP) workshops. Pollutant concentrations decreased in the order: OPEs (median 1500; range 230–410,000 ng/g) ≈ PBDEs (1200; 58–250,000) > NBFRs (140; not detected – 250,000) > CFRs (13; 0.39–2200). HFR and OPE levels in the WR workshops for e-waste and obsolete plastic were significantly higher than in the VP workshops. Decabromodiphenyl ether and decabromodiphenyl ethane are major HFRs, accounting for 60 ± 26% and 25 ± 29% of total HFRs, respectively. Triphenyl phosphate, tris(2-chloroisopropyl) phosphate, and tris(1,3-dichloroisopropyl) phosphate dominated the OPE profiles, accounting for 30 ± 25%, 25 ± 16%, and 24 ± 18% of total OPEs, respectively. The OPE profiles differed between WR and VP dust samples, implying different usage patterns of these substances in polymer materials for electric/electronic appliance and automotive industries. Human health risk related to dust-bound HFRs and OPEs in the study areas was low. [Display omitted] • Pollutant levels in dust were in the order: PBDEs ≈ OPEs > NBFRs > CFRs. • Informal e-waste recycling activities were potential source of HFRs and OPEs. • BDE-209, DBDPE, and TPHP were major compounds in e-waste recycling sites. • Vehicle workshop dust had low HFR levels and specific OPE profiles. • OPE sources and emission from vehicle processing should be further investigated. [ABSTRACT FROM AUTHOR]