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Author

Yuning Ma

Bio: Yuning Ma is an academic researcher from Indiana University. The author has contributed to research in topics: Polybrominated diphenyl ethers & Hexabromobenzene. The author has an hindex of 7, co-authored 7 publications receiving 532 citations.

Papers
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Journal ArticleDOI
TL;DR: Levels of 12 organophosphate flame retardants (OPs) were measured in particle phase samples collected at five sites in the North American Great Lakes basin from March 2012 to December 2012 as discussed by the authors.
Abstract: Levels of 12 organophosphate flame retardants (OPs) were measured in particle phase samples collected at five sites in the North American Great Lakes basin from March 2012 to December 2012 (inclusive). The target compounds were three chlorinated OPs [tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP)], three alkyl phosphates [tri-n-butyl phosphate (TnBP), tris(butoxyethyl) phosphate (TBEP), and tris(2-ethylhexyl) phosphate (TEHP)], and six aryl phosphates [triphenyl phosphate (TPP), tri-o-tolyl phosphate (TOTP), tri-p-tolyl phosphate (TPTP), tris(3,5-dimethylphenyl) phosphate (TDMPP), tris(2-isopropylphenyl) phosphate (TIPPP), and tris(4-butylphenyl) phosphate (TBPP)]. Total OP (ΣOP) atmospheric concentrations ranged from 120 ± 18 to 2100 ± 400 pg/m3 at the five sites, with the higher ΣOP levels detected at Cleveland and Chicago. ΣOP concentrations at these urban sites were dominated by the chlorinated OPs (TCEP, TCPP, and TDCP...

213 citations

Journal ArticleDOI
TL;DR: The atmospheric concentrations of TBB and TBPH increased rapidly and significantly over this time period, perhaps indicating that these compounds are replacing the polybrominated diphenyl ethers (PBDEs), which have been removed or soon will be removed from the marketplace.
Abstract: Two relatively new flame retardants, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromophthalate (TBPH), were identified and quantitated in gas and particle-phase air samples collected from six sites near the shores of the Great Lakes. TBB and TBPH were detected in more than half of the samples collected from 2008 to 2010. Urban areas, such as Chicago and Cleveland, showed the highest concentrations (0.36–290 pg/m3), while remote areas, such as Eagle Harbor and Sleeping Bear Dunes, exhibited the lowest levels (0.050–32 pg/m3). The atmospheric concentrations of TBB and TBPH increased rapidly and significantly over this time period, perhaps indicating that these compounds are replacing the polybrominated diphenyl ethers (PBDEs), which have been removed or soon will be removed from the marketplace.

110 citations

Journal ArticleDOI
TL;DR: Positive relationships indicate that the replacement of the deca-BDE commercial product by DBDPE and the penta- BDE product by Firemaster 550 have not yet become evident in the Great Lakes' atmospheric environment.
Abstract: Air and precipitation samples were collected every 12 days at five sites near the North American Great Lakes from 2005 to 2011 (inclusive) by the Integrated Atmospheric Deposition Network (IADN). The concentrations of polybrominated diphenyl ethers (PBDEs) and selected alternative brominated flame retardants [pentabromoethyl benzene (PBEB), hexabromobenzene (HBB), 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE or BTBPE), decabromodiphenylethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), and bis(2-ethylhexyl)-tetrabromo-phthalate (TBPH)] were measured in these samples. The concentrations of almost all of these flame retardants were related to the number of people within a 25 km radius of the sampling site, except for HBB, the concentrations of which were relatively high at Sturgeon Point, and PBEB, the concentrations of which were relatively high at Eagle Harbor. The temporal trends of all of these concentrations were variable. For example, BDE-47 vapor phase concentrations were increasing with dou...

107 citations

Journal ArticleDOI
TL;DR: The atmospheric concentrations of PBT, pTBX, PBBB, and PBBA tracked local human population density, suggesting that these compounds are or were used in a variety of commercial products.
Abstract: Seven bromobenzene flame retardants were measured in vapor-phase samples collected at five sites, all near the shores of the North American Great Lakes during 2008-2009, inclusive. The target compounds were hexabromobenzene (HBB), pentabromobenzene (PBBz), pentabromotoluene (PBT), pentabromobenzylacrylate (PBBA), pentabromobenzyl bromide (PBBB), tetrabromo-p-xylene (pTBX), and pentabromoethyl benzene (PBEB). Detection frequencies were, on average, higher than 50% for all of the compounds, with the exception of PBBA, which was detected only in 22% of all the samples. Considering all the sampling sites together, HBB showed the highest average concentration (4.6 ± 1.0 pg/m(3)), followed by PBBB (3.3 ± 0.5 pg/m(3)) and PBEB (1.0 ± 0.1 pg/m(3)). The concentrations of these compounds were generally significantly correlated with one another, with the exception of PBBA, which was correlated only to PBBB. The atmospheric concentrations of PBT, pTBX, PBBB, and PBBA tracked local human population density, suggesting that these compounds are or were used in a variety of commercial products. Unexpectedly, the concentration of PBEB was highest at the remote site of Eagle Harbor in northern Michigan, whereas that of HBB was highest at Sturgeon Point, ∼25 km southwest of Buffalo, New York. The lack of dependence of these two compounds' concentrations on human population suggests local point sources.

68 citations

Journal ArticleDOI
TL;DR: The concentrations of ATE, BATE, and DPTE did not change significantly over the two-year study, but the concentrations of TBE decreased by about a factor of 2 during this time, which was statistically significant but not strong compared to the urban effect.
Abstract: The 2,4,6-tribromophenoxy moiety is a common structural feature of several brominated flame retardants, and we have previously reported on the environmental concentrations of one such compound, 1,2...

42 citations


Cited by
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Journal ArticleDOI
TL;DR: The present study shows that the release of OPs from a wide variety of commercial products and wastewater discharge might be considered as primary emission sources and that high potential of long-range atmospheric transport and persistence of OP would be responsible for their presence in various matrices on a global scale.

822 citations

Journal ArticleDOI
TL;DR: In this article, the occurrence and spatial distribution of 11 OPE congeners and one synthetic intermediate triphenylphosphine oxide (TPPO) in 40 major rivers entering into the Bohai Sea were investigated.

296 citations

Journal ArticleDOI
TL;DR: Children had higher urinary levels of BDCIPP, DPHP, ip-DPHP, and TBBA as compared to their mothers, suggesting higher exposure to flame retardant levels as a result of increased hand-mouth behavior and elevated dust exposure.
Abstract: As a result of the polybrominated diphenyl ether (PBDE) ban in the mid-2000s, the chemical flame retardant market has moved toward alterative compounds including chlorinated alkyl and nonchlorinated aryl organophosphate flame retardants (OPFRs) as well as aromatic brominated compounds such as Firemaster 550 (FM550). Recent studies have shown that the OPFRs and Firemaster 550 components are frequently detected in polyurethane foams and in indoor dust. Some OPFRs are considered carcinogenic and/or neurodevelopmental toxicants, and children's exposure to these compounds is a concern. OPFRs are readily metabolized and excreted in the urine as their dialkyl and diaryl compounds which function as biomarkers for OPFR exposure. Limited research has shown that adults are broadly exposed to OPFRs, but nothing is known about children's exposure. Similarly, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), a FM550 component, is metabolized to tetrabromobenzoic acid (TBBA). The current study measured levels of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(1-chloro-2-propyl) phosphate (BCIPP), diphenyl phosphate (DPHP), 2 alkylated DPHPs, and TBBA in urine collected in 2013 from 21 US mother-toddler pairs. BDCIPP, DPHP, and ip-DPHP were detected in 100%, 98%, and 96% of all individuals, whereas BCIPP and tert-butyl-DPHP (tb-DPHP) were only detected in 8% and 13%. Further, TBBA was detected in 27% of adults but 70% of children. Overall, children had higher urinary levels of BDCIPP, DPHP, ip-DPHP, and TBBA as compared to their mothers, suggesting higher exposure. For example, on average, BDCIPP levels in children were 4.9 times those of mothers. BDCIPP and DPHP levels in mother's urine were also significantly correlated with levels in children's urine, suggesting similar exposure routes, likely in the home environment. Various potential predictors of OPFR exposure were assessed using a questionnaire. In children some predictors of hand-mouth exposure were associated with elevated BDCIPP and DPHP levels (e.g., less frequent hand washing for BDCIPP). Overall, these trends are consistent with higher flame retardant levels in children as a result of increased hand-mouth behavior and elevated dust exposure.

268 citations

Journal ArticleDOI
TL;DR: Results are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels and induced phenotypic hallmarks associated with metabolic syndrome in the offspring.
Abstract: Firemaster® 550 (FM 550), a fire-retardant mixture used in foam-based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 µg/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels.

243 citations

Journal ArticleDOI
TL;DR: Levels of 13 organophosphate esters (OPEs) and 45 brominated and chlorinated flame retardants (BFRs) were measured in particle phase atmospheric samples collected at Longyearbyen on Svalbard in the European Arctic from September 2012 to May 2013, and ΣOPE concentrations were 1-2 orders of magnitude higher than the ΣBFR concentrations.
Abstract: Levels of 13 organophosphate esters (OPEs) and 45 brominated and chlorinated flame retardants (BFRs) were measured in particle phase atmospheric samples collected at Longyearbyen on Svalbard in the European Arctic from September 2012 to May 2013. Total OPE (ΣOPEs) concentrations ranged from 33 to 1450 pg/m3, with the mean ΣOPE concentration of 430 ± 57 pg/m3. The nonchlorinated tri-n-butyl phosphate (TnBP) and 2-ethylhexyl-diphenyl phosphate (EHDPP) were the most abundant OPE congeners measured, and the sum of all nonchlorinated OPE concentrations comprised ∼75% of the ΣOPE concentrations. The most abundant chlorinated OPE was tris(1-chloro-2-propyl) phosphate (TCPP). Total BFR concentrations (ΣBFRs) were in the range of 3–77 pg/m3, with a mean concentration of 15 ± 3 pg/m3. 2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl)tetrabromophthalate (TBPH) were among the relatively abundant BFRs measured in these samples and comprised ∼46% and 17% of ΣBFR concentrations, respectively. Total PBD...

240 citations