Contamination status, emission sources, and human health risk of brominated flame retardants in urban indoor dust from Hanoi, Vietnam: the replacement of legacy polybrominated diphenyl ether mixtures by alternative formulations.

This study investigated the occurrence, distribution of several additive brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and some novel brominated flame retardants (NBFRs) in urban indoor dust collected from ten inner districts of Hanoi, Vietnam to assess the contamination status, emission sources, as well as their associated human exposure through indoor dust ingestion and health risks. Total concentrations of PBDEs and NBFRs in indoor dust samples ranged from 43 to 480 ng g-1 (median 170 ng g-1) and from 56 to 2200 ng g-1 (median 180 ng g-1), respectively. The most abundant PBDE congener in these dust samples was BDE-209 with concentrations ranging from 29 to 360 ng g-1, accounting for 62.6-86.5% of total PBDE levels. Among the NBFRs analyzed, decabromodiphenyl ethane (DBDPE) was the predominant compound with a mean contribution of 98.6% total NBFR amounts. Significant concentrations of DBDPE were detected in all dust samples (median 180 ng g-1, range 54-2200 ng g-1), due to DBDPE as a substitute for deca-BDE. Other NBFRs such as 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), pentabromoethylbenzene (PBEB) and 2,2',4,4',5,5'-hexabromobiphenyl (BB-153) were found at very low levels. Based on the measured BFR concentrations, daily intake doses (IDs) of PBDEs and NBFRs via dust ingestion at exposure scenarios using the median and 95th percentile levels for both adults and children were calculated for risk assessment. The results showed that the daily exposure doses via dust ingestion of all compounds, even in the high-exposure scenarios were also lower than their reference dose (RfD) values. The lifetime cancer risks (LTCR) were much lower than the threshold level (10-6), which indicated the acceptable health risks resulting from indoor BFRs exposure for urban residents in Hanoi.

Hoang MTT ，Anh HQ ，Kadokami K ，Duong HT ，Hoang HM ，Van Nguyen T ，Takahashi S ，Le GT ，Trinh HT ... -  《-》

PBDEs and novel brominated flame retardants in road dust from northern Vietnam: Levels, congener profiles, emission sources and implications for human exposure.

Polybrominated diphenyl ethers (PBDEs) and selected novel brominated flame retardants (NBFRs) were examined in road dust samples collected from three representative areas in northern Vietnam, including seven inner districts of Hanoi metropolitan area, an industrial park in Thai Nguyen province and a rural commune in Bac Giang province. This study aims to provide basic information on the contamination status, potential sources and human exposure to PBDEs and NBFRs associated with road dust in northern Vietnam. PBDEs were detected in all the samples at a range of 0.91-56 ng g-1 with a median value of 16 ng g-1. PBDE concentrations in road dusts from urban sites were significantly higher than those from industrial zone and rural area, suggesting their environmental load related to urbanization in northern Vietnam. BDE-209, major component of deca-BDE technical mixtures, dominated the congener patterns in all samples, accounting for 60.8-91.9% of total PBDE levels. Decabromodiphenyl ethane, an alternative of deca-BDE, was observed in a detection frequency of 100% in urban and industrial areas and at levels comparable to those of BDE-209. Other NBFRs such as pentabromoethylbenzene, hexabromobiphenyl and 1,2-bis-(2,4,6-tribromophenoxy)ethane, were found at trace levels. Daily intake doses of PBDEs via road dust ingestion from 2.3 × 10-5 to 0.11 ng kg-bw-1 d-1 were estimated for residents in study areas, indicating a negligible risk with hazard indexes of 10-9 to 10-5 for selected congeners such as BDE-47, 99, 153 and 209.

Anh HQ ，Tomioka K ，Tue NM ，Tri TM ，Minh TB ，Takahashi S ... -  《-》

Organophosphate compounds, polybrominated diphenyl ethers and novel brominated flame retardants in European indoor house dust: Use, evidence for replacements and assessment of human exposure.

52 pollutants including organophosphate flame retardants and plasticizers (OPs), polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs) were evaluated in household dust from Belgium, Italy and Spain. Pollutant pattern was dominated by ∑OPs (12.8 μg/g; median) followed in decreasing order by ∑PBDEs (229 ng/g), decabromodiphenyl ethane (DBDPE, 130 ng/g), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE, 1.35 ng/g), hexabromobenzene (HBB, 0.28 ng/g) and finally pentabromoethylbenzene (PBEB, 0.03 ng/g). Country differences and substitution of regulated chemicals by unregulated ones were explored. Results clearly reflected a decrease in c-penta and c-octaBDE commercial mixtures, which are mainly substituted by OPs, BTBPE and PBEB. On the other hand, c-decaBDE concentrations increased in Spanish case. However, positive correlations with its proposed substitute (DBDPE) and recent restricted policies make it possible to assume that this trend will change in the coming years. On the basis of the relationship between pollutants, house characteristics and inhabitant habits, potential sources were studied. Finally, data obtained were used to determine estimated daily intakes (EDI) via house dust ingestion and dermal absorption for toddlers and adults at central and upper percentiles. Calculated EDI levels even at worst case scenario were below available reference dose (RfD) values in all cases.

de la Torre A ，Navarro I ，Sanz P ，de Los Ángeles Martínez M ... -  《-》

Concentrations of legacy and novel brominated flame retardants in indoor dust in Melbourne, Australia: An assessment of human exposure.

Polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFR) have been used in a range of polymers to inhibit the spread of fires but also have a propensity to migrate out of consumer materials and contaminate indoor dust. In this study, a total of 57 dust samples were collected from 12 homes, eight offices and eight vehicles in Melbourne, Australia and analysed for eight PBDEs (-28, -47, -99, -100, -153, -154, -183 and -209) and seven NBFRs (PBT, PBEB, HBB, EH-TBB, BEH-TEBP, BTBPE and DBDPE) to determine human exposure risks from dust ingestion. Samples were analysed using selective pressurized liquid extraction (S-PLE) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Legacy and replacement flame retardants were detected in all samples with overall ∑PBDE concentrations ranging from 120 to 1700,000 ng/g (median 2100 ng/g) and ∑NBFRs ranging from 1.1 to 10,000 ng/g (median 1800 ng/g). BDE-209 and DBDPE were the dominant compounds in dust samples, followed by congeners associated with commercial Penta-BDE formulations (-47, -99, -100, -153 and -154) and then EH-TBB of the FireMaster 550 and BZ-54 products. ∑Penta-BDE concentrations were elevated in office samples compared with homes and vehicles, while EH-TBB and BDE-209 measured higher concentrations in vehicles compared with their respective levels in homes and offices. Risk assessment estimates revealed the majority of exposure to occur in the home for both adults and toddlers in the City of Melbourne. Generally, body weight adjusted exposure to PBDEs and NBFRs was predicted to be 1 to 2 orders of magnitude higher for toddlers than adults. Estimated rates of BDE-47, -99, -153 and -209 ingestion were each 2 orders of magnitude or more below the USEPA's prescribed oral reference dose values (RfDs) for typical exposure scenarios. However, exposure rates for BDE-47 and -99 reached as high as 52 and 95% of RfDs, respectively, for adults and 4.4 and 7.4%, respectively, for toddlers in high exposure scenarios. This study provides the first wide-ranging survey of NBFRs in indoor dust from homes, offices and vehicles in Australia and offers further evidence of human exposure to legacy and novel brominated flame retardants via dust ingestion.

McGrath TJ ，Morrison PD ，Ball AS ，Clarke BO ... -  《-》

Legacy and novel brominated flame retardants in interior car dust - Implications for human exposure.

Brominated flame retardants (BFRs) are organobromine compounds with an inhibitory effect on combustion chemistry tending to reduce the flammability of products. Concerns about health effects and environmental threats have led to phase-out or restrictions in the use of Penta-, Octa- and Deca-BDE technical formulations, increasing the demand for Novel BFRs (NBFRs) as replacements for the banned formulations. This study examined the occurrence of legacy and NBFRs in the dust from the interior of private cars in Thessaloniki, Greece, aged from 1 to 19 years with variable origin and characteristics. The determinants included 20 Polybrominated Diphenyl Ethers (PBDEs) (Di-to Deca-BDEs), four NBFRs such as Decabromodiphenylethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH), three isomers of hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA). The concentrations of ∑20PBDE ranged from 132 to 54,666 ng g-1 being dominated by BDE-209. The concentrations of ∑4NBFRs ranged from 48 to 7626 ng g-1 and were dominated by DBDPE, the major substitute of BDE-209. HBCDs ranged between <5 and 1745 ng g-1, with alpha-HBCD being the most prevalent isomer Finally, the concentrations of TBBPA varied from <10 to 1064 ng g-1. The concentration levels and composition profiles of BFRs were investigated in relation to the characteristics of cars, such as year of manufacture, country of origin, and interior equipment (type of car seats, electronic and electrical components, ventilation, etc.). The average daily intakes of selected BFRs (BDE-47, BDE-99, BDE-153, BDE-209, TBB, BTBPE, TBPH, DBDPE, HBCDs and TBBPA) via ingestion and dermal absorption were estimated for adults and toddlers. The potential health risk due to BFRs was found to be several orders of magnitude lower than their corresponding reference dose (RfD) values.

Besis A ，Christia C ，Poma G ，Covaci A ，Samara C ... -  《-》