Heterogeneous OH Initiated Oxidation: A Possible Explanation for the Persistence of Organophosphate Flame Retardants in Air
07 Jan 2014-Environmental Science & Technology (American Chemical Society)-Vol. 48, Iss: 2, pp 1041-1048
TL;DR: The results demonstrate that particle bound OPEs are highly persistent in the atmosphere with regard to OH radical oxidation, consistent with the assumption that O PEs can undergo medium or long-range transport, as previously proposed on the basis of field measurements.
Abstract: Heterogeneous reactions between OH radicals and emerging flame retardant compounds coated on inert particles have been investigated. Organophosphate esters (OPEs) including triphenyl phosphate (TPhP), tris-2-ethylhexyl phosphate (TEHP), and tris-1,3-dichloro-2-propyl phosphate (TDCPP) were coated on (NH4)2SO4 particles and exposed to OH radicals in a photochemical flow tube at 298 K and (38.0 ± 2.0) % RH. The degradation of these particle-bound OPEs was observed as a result of OH exposure, as measured using a Time-of-Flight Aerosol Mass Spectrometer. The derived second-order rate constants for the heterogeneous loss of TPhP, TEHP, and TDCPP were (2.1 ± 0.19) × 10–12, (2.7 ± 0.63) × 10–12, and (9.2 ± 0.92) × 10–13 cm3 molecule–1 s–1, respectively, from which approximate atmospheric lifetimes are estimated to be 5.6 (5.2–6.0), 4.3 (3.5–5.6), and 13 (11–14) days. Additional coating of the OPE coated particles with an OH radical active species further increased the lifetimes of these OPEs. These results repre...
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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
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
TL;DR: The present review outlines the current state of knowledge regardimg the analytical methodology applied for OPFRs determination in wastewater and aquatic environment as well as their occurrence in water, wastewater, sediments and sludge.
196 citations
TL;DR: Concentrations of halogenated and nonhalogenated OPEs seemed to be driven by river discharge from the Nelson and Churchill Rivers (Manitoba) and Churchill River and Lake Melville (Newfoundland and Labrador) and local sources close to the land-based sampling stations.
Abstract: Fourteen organophosphate esters (OPEs) were measured in the filter fraction of 117 active air samples from yearly ship-based sampling campaigns (2007–2013) and two land-based stations in the Canadian Arctic, to assess trends and long-range transport potential of OPEs. Four OPEs were detected in up to 97% of the samples, seven in 50% or less of the samples, and three were not detected. Median concentrations of ∑OPEs were 237 and 50 pg m–3 for ship- and land-based samples, respectively. Individual median concentrations ranged from below detection to 119 pg m–3 for ethanol, 2-chloro-, phosphate (3:1) (TCEP). High concentrations of up to 2340 pg m–3 were observed for Tri-n-butyl phosphate (TnBP) at a land-based sampling location in Resolute Bay from 2012, whereas it was only detected in one ship-based sample at a concentration below 100 pg m–3. Concentrations of halogenated OPEs seemed to be driven by river discharge from the Nelson and Churchill Rivers (Manitoba) and Churchill River and Lake Melville (Newfou...
140 citations
TL;DR: It is highlighted that OPEs are subject to long-range transport via both air and seawater from the European continent and seas to the North Atlantic and the Arctic.
Abstract: The concentrations of eight organophosphate esters (OPEs) have been investigated in air, snow and seawater samples collected during the cruise of ARK-XXVIII/2 from sixth June to third July 2014 across the North Atlantic and the Arctic. The sum of gaseous and particle concentrations (ΣOPE) ranged from 35 to 343 pg/m3. The three chlorinated OPEs accounted for 88 ± 5% of the ΣOPE. The most abundant OPE was tris(2-chloroethyl) phosphate (TCEP), with concentrations ranging from 30 to 227 pg/m3, followed by three major OPEs, such as tris(1-chloro-2-propyl) phosphate (TCPP, 0.8 to 82 pg/m3), tri-n-butyl phosphate (TnBP, 2 to 19 pg/m3), and tri-iso-butyl phosphate (TiBP, 0.3 to 14 pg/m3). The ΣOPE concentrations in snow and seawater ranged from 4356 to 10561 pg/L and from 348 to 8396 pg/L, respectively. The atmospheric particle-bound dry depositions of TCEP ranged from 2 to 12 ng/m2/day. The air–seawater gas exchange fluxes were dominated by net volatilization from seawater to air for TCEP (mean, 146 ± 239 ng/m2/...
132 citations
References
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2,290 citations
TL;DR: In this paper, the use of PFRs as potential substitutes for brominated flame retardants (BFRs) has been discussed and a number of potential alternatives for BFRs have been proposed.
1,953 citations
1,200 citations
Book•
01 Jan 1970
TL;DR: In this article, the processes leading to the formation of high-dispersed aerosols with particle size below 0.1 μ and the methods of generation and investigation of these aerosols are treated as well as their physical properties differing fundamentally from those of coarse aerosols.
Abstract: The processes leading to the formation of high-dispersed aerosols with particle size below 0.1 μ and the methods of generation and investigation of these aerosols are treated as well as their physical properties differing fundamentally from those of coarse aerosols. In spite of the great role played by high-dispersed aerosols in the important process of vapor condensation in space and their significance for many industries and meteorology, there are no monographs or reviews on this subject available in the literature, and the aim of the present work is to fill this gap.
802 citations
TL;DR: Global measurements of 1,1,1-trichloroethane (CH3CCl3, methyl chloroform) provide an accurate method for determining the global and hemispheric behavior of OH, and show variations that imply important and unexpected gaps in current understanding of the capability of the atmosphere to cleanse itself.
Abstract: The hydroxyl radical (OH) is the dominant oxidizing chemical in the atmosphere. It destroys most air pollutants and many gases involved in ozone depletion and the greenhouse effect. Global measurements of 1,1,1-trichloroethane (CH3CCl3, methyl chloroform) provide an accurate method for determining the global and hemispheric behavior of OH. Measurements show that CH3CCl3 levels rose steadily from 1978 to reach a maximum in 1992 and then decreased rapidly to levels in 2000 that were lower than the levels when measurements began in 1978. Analysis of these observations shows that global OH levels were growing between 1978 and 1988, but the growth rate was decreasing at a rate of 0.23 ± 0.18% year−2, so that OH levels began declining after 1988. Overall, the global average OH trend between 1978 and 2000 was −0.64 ± 0.60% year−1. These variations imply important and unexpected gaps in current understanding of the capability of the atmosphere to cleanse itself.
597 citations