Article pubs.acs.org/est
Organophosphate and Halogenated Flame Retardants in Atmospheric Particles from a European Arctic Site Amina Salamova,† Mark H. Hermanson,‡ and Ronald A. Hites*,† †
School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States Department of Arctic Technology, University Center on Svalbard, NO-9171 Longyearbyen, Svalbard
‡
S Supporting Information *
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-2,3,4,5tetrabromobenzoate (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 PBDE (ΣPBDE) concentrations constituted ∼37% of ΣBFR concentrations on average and ranged from 1 to 31 pg/m3. The most abundant PBDE congener was BDE-209, which contributed 24% to ΣPBDE concentrations. Dechlorane Plus (DP) was detected in all of the samples, and ΣDP concentrations (syn- + anti-DP concentrations) ranged from 0.05 to 5 pg/m3. Overall, ΣOPE concentrations were 1−2 orders of magnitude higher than the ΣBFR concentrations.
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INTRODUCTION Organophosphate esters (OPEs) and brominated flame retardants (BFRs) are used in many consumer and industrial products to delay ignition and slow the spread of fire in order to comply with flammability regulations. Polybrominated diphenyl ethers (PBDEs) have historically been the most widely used BFRs, but these compounds now are off the market globally due to their persistence, bioaccumulation, and toxicity. In fact, several PBDE congeners were added to the Stockholm Convention on Persistent Organic Pollutants Annex A and may be banned globally from production and use.1 Because of these restrictions on PBDEs, a variety of new BFRs have been introduced as replacements. For example, the commercial Penta-BDE formulation was replaced with 2-ethylhexyl-2,3,4,5tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) [two main components of Firemaster 550 flame retardant mixture], and 1,2-bis(2,4,6tribromophenoxy)ethane (BTBPE) and decabromodiphenyl© 2014 American Chemical Society
ethane (DBDPE) replaced the Octa- and Deca-BDE commercial formulations, respectively.2 In addition, Dechlorane Plus (DP), a nonregulated, highly chlorinated flame retardant, was suggested by the European Union as a possible replacement for the Deca-BDE formulation for several applications.3 To replace the restricted PBDEs, the production and use of OPEs have increased during recent years. Halogenated (mainly chlorinated) OPEs, such as tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(1,3-dichloropropyl) phosphate (TDCPP), as well as nonhalogenated aryl OPEs, such as triphenyl phosphate (TPP) and tricresyl phosphate (TCP), are used as flame Received: Revised: Accepted: Published: 6133
February 21, 2014 April 11, 2014 April 16, 2014 May 21, 2014 dx.doi.org/10.1021/es500911d | Environ. Sci. Technol. 2014, 48, 6133−6140
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Figure 1. Map of Svalbard showing the major population centers and the location of the sampling site at 78.22 N, 15.65 E.
packaging and was found in margarine and candy,14 and it is considered potentially bioaccumulative and toxic to fish and aquatic plants.15 Like BFRs, OPEs are additive flame retardants and do not covalently bind to the material in which they are used; hence, they can leach into the environment. Consequently, OPEs have been detected throughout the environment, including in water;16,17 sediment;18 indoor air and dust;8,19,20 fish and biota;21−23 and human fat, milk, and urine.22,24−26 Data on OPEs in the ambient atmosphere, especially in remote regions, are limited; but the existing research suggests that these compounds can undergo LRAT.27−29 Specifically, the elevated levels of OPEs measured in remote North American air (up to 170 pg/m3),27 pine needles from the Sierra Nevada Mountains, United States (up to 1950 ng/g),28 and volcanic lakes in central Italy (up to 951 ng/L) are potentially due to LRAT.29 OPEs have also been detected in precipitation, suggesting atmospheric deposition of these chemicals onto terrestrial systems.30−32 Polar regions have been used for monitoring the global background levels of atmospheric pollutants because of their remote geographical locations and relatively insignificant local sources. Thus, the detection of certain atmospheric pollutants in polar air provides important knowledge on the LRAT capabilities of these chemicals. For example, Möller et al. reported OPE concentrations up to 1300 pg/m3 in airborne particles over the Arctic Ocean and higher OPE levels over the remote Pacific, Indian, and Southern Oceans33 and the North Sea,34 demonstrating the widespread global occurrence of these chemicals, including polar regions. OPEs were also detected at concentrations of about 1000 pg/m3 in aerosols from
retardants in building materials, electronics, plastics, furniture, and textiles. These OPEs are potential replacements for the Penta-BDE commercial formulation that has been taken off the market.4 The majority of nonhalogenated alkyl OPEs are used as plasticizers and antifoaming agents in hydraulic fluids, lacquers, and floor polishes.5 OPEs have been in use for several decades, and their consumption in Europe as flame retardants was about 84,000 metric tonnes in 2005.6 However, their production increased after the PBDE phase out; for example, in Western Europe, OPE production increased about 10% between 2001 and 2006.5 Production volumes for TDCPP, TPP, and TCPP in the United States increased from 500−5,000 metric tonnes in 1990 to 5,000−25,000 metric tonnes in 2006 for each of these chemicals.7 Despite these rapid increases in the use of OPEs, data on their environmental concentrations, persistence, bioaccumulation, toxicity, and long-range atmospheric transport (LRAT) are limited. For example, TCEP and TDCPP are listed as carcinogens under California Proposition 65.8 TDCPP was previously used in children’s pajamas as a flame retardant, but it was withdrawn in the late 1970s after its metabolites were detected in children’s urine and found to be mutagenic.9 More recently, TDCPP has been shown to be a neurotoxicant and to affect thyroid and reproductive hormone levels in men.10,11 TDCPP was detected in the majority of polyurethane foam samples taken from American couches and baby products required to comply with California TB-117 flammability regulation.12,13 These observations suggest that this chemical is extensively used in polymers as a possible replacement for the Penta-BDE commercial formulation. TCPP has been shown to accumulate in the liver and kidneys of rats.5 2-Ethylhexyldiphenyl phosphate (EHDPP) is approved for use in food 6134
dx.doi.org/10.1021/es500911d | Environ. Sci. Technol. 2014, 48, 6133−6140
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Table 1. Atmospheric Particle Concentrations (Mean ± Standard Error, Median, Minimum, and Maximum, pg/m3) and Detection Percentages of OPEs, BFRs, and DP Analyzed at Longyearbyen, Svalbarda compd TnBP TCEP TCPP TDCPP TPP TBEP EHDPP TEHP Σnon-ClOPEs ΣCl-OPEs ΣOPEs
mean
median
min
max
det %, N = 34
ANOVA
compd
mean
median
min
max
det %, N = 34
ANOVA
174 ± 46 19 ± 2.7 62 ± 6.3 59 ± 4.3 20 ± 2.1 100 ± 22 103 ± 13 12 ± 1.6 334 ± 54
56 15 57 10 17 63 85 9 239
5.6 4.0 10 2.3 1.1 47 5.6 1.0 19
1000 63 186 294 52 208 298 42 1351
100 97 100 19 100 25 100 97 100
a c ab bc c a a c a
BDE-47 BDE-99 BDE-209 TBB TBPH DBDPE BTBPE HBB pTBX
0.82 ± 0.12 0.69 ± 0.21 1.3 ± 0.31 7.0 ± 2.02 2.7 ± 0.49 0.53 ± 0.10 0.04 ± 0.01 0.23 ± 0.06 0.07 ± 0.01
0.59 0.33 0.46 2.2 1.8 0.27 0.03 0.12 0.07
0.23 0.07 0.12 0.17 0.27 0.04 0.01 0.01 0.01
4.1 6.8 6.8 58 14 2.2 0.09 1.7 0.16
100 100 100 91 88 88 53 100 65
b bc b a a bc f de ef
91 ± 12 426 ± 57
70 334
14 33
385 1450
100 100
b a
PBBz PBEB syn-DP anti-DP ΣDP ΣPBDEs ΣBFRs
0.14 ± 0.05 0.04 ± 0.01 0.29 ± 0.04 1.1 ± 0.19 1.2 ± 0.22 5.6 ± 1.1 15 ± 2.5
0.04 0.03 0.22 0.55 0.76 3.4 10
0.01 0.01 0.05 0.15 0.05 1.03 2.5
1.1 0.24 0.91 4.2 5.03 31 77
76 71 91 91 100 100 100
ef f cd b c b a
a
The concentrations are averaged over the period of September 2012 to May 2013, inclusive. ANOVA results for the logarithmically transformed concentrations are given; ANOVA performed for OPEs and BFRs separately; the concentrations are not significantly different at P < 0.05 for the compounds sharing the same letter. TOTP, TPTP, TIPPP, TDMPP, and TBPP are not shown since they were not detected in any of the samples.
Antarctica,35,36 and TCEP was detected in the Antarctic ice sheet.37 In this study, we present measurements of a wide range of OPEs and other halogenated flame retardants in atmospheric particle samples collected in Longyearbyen on Svalbard in the European Arctic. The samples were collected weekly from September 2012 to May 2013 using high-volume atmospheric samplers. This is the first comprehensive report on atmospheric OPE concentrations from an on-land Arctic site. The only previous overland Arctic atmospheric data for these compounds are from a screening study of three samples from Ny-Ålesund on Svalbard.38 In addition, this is the first study to directly compare the levels of the airborne OPEs to those of other flame retardants measured in the same samples. The findings reported here provide knowledge on the background levels of OPEs in small population centers in the European Arctic, as well as shed a light on the LRAT potential of OPEs and other flame retardants.
Arctic sites in North America largely because of the West Spitsbergen Current, a branch of the Gulf Stream, passing along the west coast of Svalbard. The conditions in Longyearbyen are, therefore, not necessarily a reflection of conditions elsewhere on Svalbard or in the Arctic as a whole. Analysis. A detailed description of the sample treatment and chemical analysis procedures for the particle samples has been given elsewhere.39 Briefly, the samples were spiked with known amounts of d12-tris(2-chloroethyl) phosphate, 13C18triphenyl phosphate, BDE-77, BDE-166, and 13C12−BDE-209 as surrogate standards and Soxhlet extracted for 24 h with 50% (v/v) acetone in hexane. The extract was reduced in volume by rotary evaporation, and the solvent was exchanged to hexane and fractionated on a column containing 3.5% (w/w) water deactivated silica gel. The column was eluted with 25 mL of hexane (first fraction), 25 mL of 50% (v/v) hexane in dichloromethane (second fraction), and 25 mL of 70% (v/v) acetone in dichloromethane (third fraction). The BFRs eluted in the first and second fractions, and the OPEs eluted in the third fraction. After N2 blow down, the samples were spiked with the quantitation internal standards (d10-anthracene, d12benz[a]anthracene, d12-perylene, BDE-118, and BDE-181). The samples were analyzed by electron impact gas chromatographic mass spectrometry (on an Agilent 6890 series gas chromatograph coupled to an Agilent 5973 mass spectrometer) for three chlorinated OPEs [tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP)]; for three alkyl OPEs [tri-n-butyl phosphate (TnBP), tris(butoxyethyl) phosphate (TBEP), and tris(2-ethylhexyl) phosphate (TEHP)]; and seven aryl OPEs [triphenyl phosphate (TPP), 2-ethylhexyl-diphenyl phosphate (EHDPP), 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)]. For the BFR analysis, the first and second fractions were further concentrated by N2 blow down to ∼100 μL. The
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EXPERIMENTAL SECTION Sampling. Thirty-four atmospheric particle samples were collected at Longyearbyen on Svalbard (78.22°N, 15.65°E, see Figure 1) during the period of September 2012 to May 2013. A high-volume air sampler (Tisch TE-1000, Tisch Environmental, Village of Cleves, OH) was used to collect the samples for 48 h at a flow rate giving a total sample volume of about 650 m3. The particles were collected on quartz fiber filters (Whatman QMA, 10.16 cm diameter, 2.2 μm particle size cutoff). The samples were shipped to Indiana University and stored at −20 °C until analyzed. Longyearbyen is a coal mining community of ∼2100 permanent residents (as of 2011). It was established in 1906 and became an incorporated community during the 1970s. Nearly all of the population growth and building construction has occurred since the 1980s. The daily annual mean temperature is −7.5 °C, so the use of building and pipe insulation and associated flame retardants may be extensive. While located in the Arctic, Longyearbyen is warmer than 6135
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concentrations ranging from 6 to 1000 pg/m3 for TnBP and 6 to 300 pg/m3 for EHDPP. Mean TBEP concentrations were statistically indistinguishable from the TnBP and EHDPP concentrations (see ANOVA results in Table 1), but TBEP was detected only in ∼25% of the samples with the concentrations ranging from 47 to 210 pg/m3. In addition, TPP and TEHP were detected in all the samples but at lower concentrations ranging from 1 to 52 pg/m3 and 1 to 42 pg/m3, respectively. Overall, the sum of all nonchlorinated OPE concentrations was ∼75% of the ΣOPE concentrations. Consequently, the sum of the three chlorinated OPEs (TCEP, TCPP, and TDCPP) was only ∼25% of the ΣOPE concentrations. The most abundant chlorinated OPE congener was TCPP, which was detected in all the samples with the concentrations ranging from 10 to 190 pg/m3. Average TDCPP concentrations were statistically indistinguishable from the average TCPP concentrations, but this OPE was detected only in ∼20% of the samples at concentrations ranging from 2 to 290 pg/m3. Finally, TCEP concentrations were the lowest among the levels of the chlorinated OPEs and ranged from 4 to 63 pg/m3. The latter could be a result of decreased TCEP use in Norway from 2004 to 2008, which might be related to restricted TCEP use in Europe.4 In general, the difference in distribution pattern between the chlorinated and nonchlorinated OPEs observed here may be a result of different source profiles for these two OPE groups as well as different atmospheric LRAT potentials and different atmospheric transformation and loss processes. Certainly, further research is needed on the atmospheric fates of OPEs. Comparing our data with previously published atmospheric concentrations is difficult because most studies have not measured the same set of compounds; thus, a total OPE concentration would include different compounds, and such a comparison would not be definitive. The most commonly measured OPEs are TnBP, TCEP, TCPP, TDCPP, TPP, TBEP, and TEHP. Table S1 in the Supporting Information gives a summary of their previously reported atmospheric concentrations subdivided by urban vs rural or remote sampling sites. The geometric mean concentrations of these compounds range from 40 to 870 pg/m3 at the urban sites and from 8 to 75 pg/m3 at the rural or remote sites. The geometric means of our measurements at Longyearbyen range from 9 to 58 pg/m3, which are similar to the reported rural or remote site concentrations and about 5−10 times less than the reported urban values. As discussed earlier, our OPE profile was dominated by nonchlorinated OPEs, a finding that needs to be investigated further to uncover possible local or remote sources. Keeping in mind the problems with reporting a ΣOPE concentration, overall our ΣOPE median value of ∼200 pg/m3 at Longyearbyen is similar to ΣOPE concentrations found previously at rural and remote sites and is about 10 times lower than concentrations reported previously at urban sites. It is difficult to comment on the sources of OPEs in Longyearbyen because the atmospheric transport of particles to the eastern Arctic, including Svalbard, is not well characterized beyond model predictions for common species, such as sulfur dioxide and black carbon. For these two chemical species, European (including western Russian) emissions are the dominant sources for surface air particle samples as opposed to other source regions including North America, East Asia, and South Asia, especially during winter, and to a lesser degree during summer.41 However, considering that Longyearbyen is a mining town, some influence of local sources on measured
samples were analyzed for 35 PBDE congeners (7, 10, 17, 28, 30, 47, 49, 66, 71, 85, 99, 100, 119, 126, 138−140, 153, 154, 156, 169, 180, 183, 184, 191, 196, 197, 201, and 203−209) and for decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), 1,2-bis(2,4,6tribromophenoxy)ethane (BTBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), bis(2-ethylhexyl)tetrabromophthalate (TBPH), pentabromobenzene (PBBz), tetrabromo-p-xylene (pTBX), and syn- and anti-Dechlorane Plus (DP). The analysis used electron capture negative ionization mass spectrometry on an Agilent 7890A series gas chromatograph coupled to an Agilent 5975C mass spectrometer. The details on the instrumental analyses,40 chemicals used in this study, and the quality control and quality assurance procedures are given in the Supporting Information.
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RESULTS AND DISCUSSION OPE Concentrations. Table 1 gives the mean, median, minimum, and maximum concentrations and detection frequencies for each individual OPE measured in the 34 samples collected from Longyearbyen. (Data for TOTP, TPTP, TIPPP, TDMPP, and TBPP are not given because these OPEs were not detected in any of the samples.) One-way analysis of variance (ANOVA) results for the comparison of logarithmically transformed individual OPE concentrations are also included in Table 1. Figure 2A shows the concentrations of the individual OPEs in Longyearbyen. The sum of the eight OPE concentrations shown in Figure 2A (ΣOPEs) ranged from 33 to 1450 pg/m3, with the mean ΣOPE concentration of 426 ± 57 pg/m3. The nonchlorinated TnBP and EHDPP were the most abundant OPE congeners measured in Longyearbyen’s atmosphere and were detected in all the samples at the
Figure 2. Concentrations (pg/m3) of OPEs (A) and BFRs and DP (B) in the atmospheric particle phase at Longyearbyen, Svalbard. The black horizontal line inside each box represents the median, and the red horizontal line represents the mean. The boxes represent the 25th and 75th percentiles. ANOVA results using logarithmically transformed concentrations are shown; the concentration distributions sharing the same letter are not statistically different at P < 0.05. Note that the concentrations scale is 10 times greater for panel A than for panel B. 6136
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We have previously defined f TBB as a ratio of TBB to TBB +TBPH concentrations, and we showed that this ratio in the commercial Firemaster 550 mixture was 0.77 ± 0.03.45 In this study, the f TBB averaged 0.65 ± 0.02, which is close to the ratio measured in the commercial product. This suggests that TBB and TBPH measured in Longyearbyen may well be related to Firemaster 550 emissions. ΣPBDE concentrations constituted ∼37% of ΣBFR concentrations on average and ranged from 1 to 31 pg/m3. The most abundant PBDE congener (on average) was BDE-209, which contributed 24% to ΣPBDE concentrations and was in the 0.12−6.8 pg/m3 concentration range. The common Penta-BDE formulation congeners, BDE-47 and BDE-99, were the second and third most abundant PBDEs and contributed on average ∼15% and ∼12% to the ΣPBDE concentrations. These PBDE concentrations generally agree with those previously measured at Ny-Ålesund on Svalbard,46 Alert in the Canadian Arctic,42 and during Arctic research cruises.43,44 DBDPE and BTBPE were detected in most of these samples, at average concentrations of 0.04−2.2 pg/m3 and 0.01−0.09 pg/m3, respectively. Among the bromobenzenes, HBB was detected in all samples with the concentrations ranging from 0.01 to 1.7 pg/m3. PBEB, pTBX, and PBBz were detected in ∼70% of the samples with average concentrations 5, 4, and 2 times lower than the HBB concentrations, respectively. Finally, DP was detected in almost all of the samples and ΣDP concentrations (the sum of the syn- and anti-DP) ranged from 0.05 to 5.0 pg/m3. It is important to note that DBDPE and anti-DP concentrations were not statistically different from the concentrations of the most abundant PBDE congeners (BDE-47, BDE-99, and BDE-209), which indicates increasing abundance of these two chemicals in the environment. The fractional abundance of anti-DP defined as a fraction of anti-DP in ΣDP varied from 43 to 90%, with the mean value of 75 ± 2%, which is consistent with the previously reported composition of the commercial DP mixture.47 Comparison of Atmospheric OPE and BFR Concentrations. Since OPEs are potential replacements for the discontinued PBDEs, we compared ΣOPE, total chlorinated OPE (ΣCl-OPEs), and total nonchlorinated OPE (Σnon-ClOPEs) concentrations with ΣBFR concentrations, as well as with the most abundant BFRs (TBB, TBPH, and ΣPBDEs) measured in the same samples (see Figure 3A). A one way ANOVA of ΣOPE, ΣCl-OPE, Σnon-Cl-OPE, ΣBFR, ΣPBDE, TBB, and TBPH concentrations showed that ΣOPE, ΣCl-OPE, and Σnon-Cl-OPE concentrations are significantly higher (P < 0.001) compared to ΣBFR, ΣPBDE, TBB, and TBPH concentrations. Overall, ΣOPE, Σnon-Cl-OPE, and ΣCl-OPE concentrations are ∼150, 100, and 35 times higher (on average) than the BFR concentrations, respectively (see Figure 3B). In other words, atmospheric OPE concentrations measured at Longyearbyen are 1−2 orders of magnitude higher than corresponding BFR concentrations, which is consistent with the OPE-BFR ratios found for the North American Great Lakes basin27 and oceanic air over the Northern Pacific.33 In fact, OPE concentrations measured in this study are 1−2 orders of magnitude higher than any BFR (specifically, PBDE) concentrations historically measured in the Arctic atmosphere, even those measured during active PBDE production and use. Figure 4 shows literature data on PBDE atmospheric concentrations48−52 measured at various Arctic sites since the 1990s. With the exception of two high values found at Alert and Tagish in 1994/1995, which were attributed
OPE concentrations is possible. Further research is needed to distinguish between local and remote OPE sources in Longyearbyen. There are only two studies that have measured atmospheric OPE concentrations in the Arctic environment: Green et al. reported ΣOPE concentrations of ∼120−1100 pg/m3 in three particle phase samples collected at Ny-Ålesund, which is located 115 km northwest of Longyearbyen,38 and Möller et al. reported ΣOPE concentrations ranging from 240 to 1270 pg/ m3 in particle samples collected over the Arctic Ocean.33 Interestingly, both of these studies reported that chlorinated OPEs dominated the ΣOPEs congener profile, which is different from our findings, which show that nonchlorinated OPEs are the most abundant OPE congeners detected in Longyearbyen. For example, Möller et al.33 reported median contributions for TCEP and TCPP as 52 ± 6% and 38 ± 11% relative to the ΣOPE concentrations, respectively, which is about twice as high as we found in our samples. However, Green et al.38 reported EHDPP as the second most abundant OPE, which agrees with our findings. On the other hand, the OPE congener profile found in our samples agrees with the ΣOPEs congener profiles measured at North American remote sites, where the nonchlorinated OPEs, TnBP, TBEP and TPP, were found to comprise up to 85% of the ΣOPE concentrations.27 Our measured concentrations in Longyearbyen are also similar to those measured in Antarctica. Ciccioli et al.35 reported OPE concentrations of ∼1000 pg/m3 in aerosols from Antarctica; however, congener amounts were not reported. Cheng et al. detected the highest TCPP concentrations in ocean aerosols near the Antarctic Peninsula during a global research cruise.36 Our results and the literature suggest that the global atmospheric background level of total OPE is about 200−400 pg/m3 (see Table S1 in the Supporting Information). Other Halogenated Flame Retardant Concentrations. Along with the OPEs, we also measured many brominated flame retardants (BFRs) and Dechlorane Plus (DP) to have a direct comparison between these flame retardants and the OPE concentrations. Table 1 gives the mean, median, minimum, and maximum concentrations and detection frequencies for each individual BFR and DP measured in the 34 samples from Longyearbyen. One-way ANOVA results for the comparison of the logarithmically transformed individual BFR and DP concentrations are also included in Table 1. Figure 2B shows the concentrations of total BFRs (ΣBFRs, the sum of 35 PBDE congeners, pTBX, PBBz, PBEB, HBB, TBB, TBPH, BTBPE, and DBDPE), total PBDEs (ΣPBDEs, the sum of 35 PBDE congeners), DP (the sum of the syn- and anti-DP), BDE-47, BDE-99, BDE-209, TBB, TBPH, DBDPE, BTBPE, HBB, pTBX, PBBz, PBEB, and syn-and anti-DP. ΣBFR concentrations were in the range of 3−77 pg/m3, with the average concentration of 15 ± 3 pg/m3. TBB and TBPH were the dominant non-PBDE BFRs measured in these samples and comprised ∼46% and 17% of ΣBFR concentrations, respectively. TBB and TBPH concentrations varied from 0.2 to 58 pg/m3 and 0.3 to 14 pg/m3, respectively, and were higher than concentrations previously reported for atmospheric samples collected in the Canadian and European Arctic42,43 and over the Arctic Ocean44 in 2006−2010. TBB and TBPH are major components of Firemaster 550, a Penta-BDE formulation replacement, and the presence of relatively higher TBB and TBPH concentrations in our samples could be related to the recent increase in the use of Firemaster 550. 6137
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imply that OPEs persist in the atmosphere and may undergo LRAT. Interestingly, it has recently been shown that particlebound OPEs are persistent in the atmosphere with regard to OH-initiated oxidation, with estimated atmospheric lifetimes ranging from ∼6 days for nonchlorinated OPEs to ∼14 days for TDCPP.53 These particle phase OPE lifetimes are several times longer than those estimated for the OH initiated OPE oxidation in the gaseous phase (
