A review of halogenated natural products in Arctic, Subarctic andNordic ecosystems
Terry F. Bidleman a, *, Agneta Andersson b, c, Liisa M. Jantunen d, John R. Kucklick e,Henrik Kylin f, g, Robert J. Letcher h, Mats Tysklind a, Fiona Wong i
a Department of Chemistry, Umeå University, Linnaeus v€ag 6, SE-901 87, Umeå, Swedenb Department of Ecology and Environmental Science, Umeå University, Linnaeus v€ag 6, SE-901 87, Umeå, Swedenc Umeå Marine Sciences Centre, SE-905 71, H€ornefors, Swedend Centre for Atmospheric Research Experiments, Environment and Climate Change Canada, 6248 Eighth Line, Egbert, ON, L0L 1N0, Canadae Chemical Sciences Division, National Institute of Standards and Technology, Hollings Marine Laboratory, 221 Fort Johnson Road, Charleston, SC, 29412,USAf Department of Thematic Studies e Environmental Change, Link€oping University, SE-581 83, Link€oping, Swedeng Research Unit: Environmental Sciences and Management, NortheWest University, Potchefstroom, South Africah Ecotoxicology and Wildlife Health Division, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON,K1A OH3 Canadai Air Quality Processes Research Section, Environment and Climate Change Canada, Toronto, ON, M5H 5T4, Canada
a r t i c l e i n f o
Article history:Received 11 December 2018Received in revised form18 February 2019Accepted 21 February 2019
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e11590
comprise many classes of compounds, ranging in complexity fromhalocarbons (mostly halomethanes and haloethanes) to highermolecular weight compounds, which often contain oxygen and/ornitrogen atoms in addition to halogens [1,2]. Many HNPs are bio-synthesized by marine bacteria, macroalgae, phytoplankton, tuni-cates, corals, worms, sponges and other invertebrates [1e12].Terrestrial plants, lichens, bacteria and fungi also produce HNPs [2]and they are found in freshwater environments [13e17]. Thousandsof HNP compounds have been discovered [1e4,10,15,16].
Natural and anthropogenic halocarbons have important func-tions in regulating tropospheric and stratospheric ozone [18].Several of the higher molecular weight HNPs are toxic and some ofthem bioaccumulate and have similar toxic properties as those ofanthropogenic persistent organic pollutants (POPs). A detailedassessment of halocarbon sources and impacts was published bythe World Meteorological Organization [18], and both HNP classeswere reviewed in Chapter 2.16 of the Arctic Monitoring andAssessment Program (AMAP) assessment Chemicals of EmergingArctic Concern [19]. This review summarizes the occurrence andfate of higher molecular weight HNPs (hereafter called simply“HNPs”) in the Arctic-Subarctic physical environment and biota,and is adapted from Chapter 2.16 of the AMAP report, with updatessince 2016. As in that chapter, the focus is on Arctic-Subarcticecosystems, with the inclusion of the Baltic Sea, Sweden westcoast (Skagerrak) and Norwegian coastal waters. Compared to thewealth of information on POPs [20,21] and emerging chemicals ofconcern (other papers in this Special Issue), data for HNPs in thesecold climate ecosystems is sparse, or non-existent for some com-pounds. Emphasis is placed on those HNPs which have POPs-likeproperties [9e11,22e27] as these bioaccumulate and sometimesbiomagnify in top predators. Selected studies from Antarctic,temperate, and tropical regions are included to provide context.
The higher molecular weight HNPs are diverse and abundant.Non-target screening has proven effective for identifying thesecompounds [28]; e.g. hundreds of compounds were found insponge extracts and/or dolphin blubber by two-dimensional gaschromatography e time of flight mass spectrometry (GCxGC-ToF-MS) [29e31] or GC-MS with selected ion monitoring in electronimpact or electron capture modes [32]. Thousands of brominatedand iodated compounds (natural and synthetic) were found in lakeand Arctic Ocean sediments using liquidchromatographyeultrahigh resolution MS [15,16]. Bromophenoliccompounds are common in biota. These comprise bromophenols(BPs) and compounds derived from them: bromoanisoles (BAs),hydroxylated bromodiphenyl ethers (OH-BDEs), methoxylatedbromodiphenyl ethers (MeO-BDEs), and polybrominated dibenzo-p-dioxins (PBDDs). Less frequently reported compound classes are2,20-dimethoxy-3,30,5,50-tetrabromobiphenyl (2,20-dimethoxy-BB80), polyhalogenated 10-methyl-1,20-bipyrroles (PMBPs), poly-halogenated 1,10-dimethyl-2,20-bipyrroles (PDBPs), poly-halogenated N-methylpyrroles (PMPs), polyhalogenated N-methylindoles (PMIs), bromoheptyl- and bromooctyl- pyrroles,(1R,2S,4R,5R,10E)-2-bromo-1-bromomethyl-1,4-dichloro-5-(20-chloroethenyl)-5-methylcyclohexane (mixed halogenated com-pound MHC-1), polybrominated hexahydroxanthene derivatives(PBHDs) and polyhalogenated carbazoles (PHCs). Structures ofthese HNPs are shown in Fig. 1 and reported occurrences in Arctic-Subarctic and Baltic media are summarized in Table 1.
2. Physicochemical properties
Physicochemical properties of HNPs are summarized in Table 2,with a more extensive listing in Table S1 of SupplementaryInformation. Properties listed are the ionization constant (for BPsand OH-BDEs, as pKA) octanol-water partition coefficient (log KOW),
air-water partition coefficient (log KAW), octanol-air partition co-efficient (log KOA), liquid-phase vapor pressure (log PL/Pa) andliquid-phase water solubility (log SL/mol m�3). Experimentalproperties are selected wherever possible, otherwise they havebeen estimated from various models. Only a few values of KAW havebeen directly measured and most were estimated from KAW ¼ KOW/KOA, or KAW ¼ PL/(SL*RT). Papers reporting properties for OH-BDEsand MeO-BDEs include congeners in addition to those listed inTable S1. The pKA values for all 209 OH-BDE congeners have beenpredicted by SPARC [33]. Vapor pressures and KOA values for OH-BDEs, MeO-BDEs [34,35] and vapor pressures of PDBPs [26] weredetermined by chromatographic methods and these studies alsoinclude temperature dependence.
3. Sources and production
HNPs are produced by marine bacteria [5], macroalgae andphytoplankton [2,36e48] and marine invertebrates[1e4,6e9,11,49e55]. ”Produced” is used loosely here, because it isnot always clear whether the HNP synthesis occurs in the particularnamed organism or associated symbionts, e.g. cyanobacteria [51].
A general scheme for production of organobromines by marinealgae is shown in Fig. 2 [56]. Hydrogen peroxide, released duringphotosynthesis and photorespiration, oxidizes seawater bromideunder catalysis by vanadium bromoperoxidase. Oxidized brominespecies then react with organic substrates to form organobromines.Such reactions may have a protective effect by removing excesshydrogen peroxide, which can cause oxidative damage to the algae[57]. Biosynthesis of BPs by macroalgae occurs from the substratesphenol, 4-hydroxybenzoic acid and 4-hydroxybenzyl alcohol underbromoperoxidase catalysis [41,58,59]. BPs are reactively coupled toform other bromophenolic compounds: BAs, OH-BDEs, MeO-BDEsand PBDDs (Fig. 3). Several pathways have been reported forgenerating OH-BDEs and MeO-BDEs from BPs (also discussed inSection 4), viz. bromoperoxidase-catalyzed dimerization [60],photolysis [61] and reactive coupling on the surface of d-MnO2(birnessite, a naturally occurring hydrous manganese dioxide) [62].PBDDs are derived from BPs by bromoperoxidase-catalyzedcoupling [63], and by photolysis of OH-BDEs [64e66]. Marinebacteria also produce OH-BDEs and MeO-BDEs [5]. Marine spongescontain these and more complex polybrominated diphenyl ethers(PBDEs) substituted with multiple OH groups and mixed halogens[6]. Cyanobacteria symbionts of the marine sponge family Dysi-deidae have long been known to produce OH-BDEs and other HNPs[67], and recently biosynthetic gene clusters for production wereidentified [7]. Dioxins and OH-BDEs substituted with both bromineand chlorine have been identified in a marine alga and mussels[68].
Other high molecular weight HNPs (Fig. 1) also have sources inmarine bacteria, algae, worms and sponges; 2,3,4,5-tetrabromo-1-methylpyrrole was identified in the seagrass Halophila ovalis [69]and many polyhalogenated 1,10-dimethyl-2,20-bipyrroles (PDBPs)were found in sea cucumber (Holothuria spp.) [70]. The poly-halogenated 10-methyl-1,20-bipyrroles (PMBPs), like the PDBPs, area diverse set of compounds of which the first discovered in the late1990s was the 2,3,30,4,40,5,50-heptachloro-10-methyl-1,20-bipyrrole,or Q1 [71]. Q1 and mixed Cl- and Br-PMBP congeners have subse-quently been reported in many species of marine biota [22,72e74]particularly from the Pacific Ocean [24]. Recent work points to amicrobial source of these compounds based on compound-specificstable nitrogen determination [75]. Evidence of an abiotic pathwayhas also been presented, ozone-activated halogenation of 1,10-dimethyl-2,20-bipyrrole and 10-methyl-1,20-bipyrrole to form manyof the polyhalogenated species found in nature [76]. MHC-1 wasfirst detected in fish and seal [77]. Over 120 HNPs have been
Fig. 1. Structures of some HNPs reported in arctic-subarctic environments.. PMPs, PMIs, PDBPs, and MHC-1 structures drawn after [22] where substitutions refer to compoundsfound in the North Sea, and tetrabromo-PBHD drawn after [54].
Table 1Reported occurrence of HNPs in Arctic-Subarctic and Baltic environmentsa.
Compound class Atmosphere Terrestrial Freshwater Marine
Air Precip. Soil Biota Water Sediment Biota Water Sediment Biota
BPs X X Xb X XBAs X X X X X X XOH-BDEs Xb XMeO-BDEs Xb X X Xb X2,20-DiMeO-BB80 XPBDDs Xb Xb Xb
PDBPs Xc X XPBHDs XMHC-1 X
a See Fig. 1 for abbreviations.b Baltic Sea only.c Compound Q1.
Monobromo- 8.82 4.16 4.14 8.30 �1.76Dibromo- 8.94 to 9.11 4.63 to 4.73 �5.23 to �4.60 9.23 to 9.96 �2.77Tribromo- 7.53 to 8.18 5.13 to 5.51 �4.78 10.29 �3.82Tetrabromo- 6.12 to 7.27 5.93 to 6.59 �5.16 to �4.24 10.68 to 11.12 �4.94 to �4.33Pentabromo- 5.20 to 7.22 6.36 to 6.83 �4.78 to �6.12 11.47 to 12.42 �6.12 to �5.22Hexabromo- 5.25 to 6.94 7.04 to 7.23 �6.11 to �5.07 12.20 to 13.29 �6.63 to �6.11
MeO-BDEsc
Monobromo- 4.68Dibromo- 4.98 to 5.62Tribromo- 5.74 to 6.06 �4.10 10.16 �3.79Tetrabromo- 6.35 to 7.17 �4.35 to �3.67 10.64 to 10.84 �4.49 to �5.11Pentabromo- 7.00 to 7.36 �4.89 to �4.25 11.43 to 12.07 �6.23 to �5.50Hexabromo- 7.67 to 7.84 �5.16 to �4.40 12.20 to 13.00 �6.50 to �6.39
a Properties are at 25 �C unless stated otherwise. See Fig. 1 for compound abbreviations.b Details and references in Table S1.c Range of properties for congeners listed in Table S1.d Estimated pKA values for all 209 congeners are given in Ref. [33].
Fig. 2. General scheme for production of organobromine compounds by marine algae, involving oxidation of seawater bromide by hydrogen peroxide under catalysis by vanadiumbromoperoxidase (V-BrPO) and subsequent reaction of oxidized bromine species with organic substrates. From Ref. [56].
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e11592
identified in the Polychaete class of Annilida worms and manyecological functions have been attributed to them, including de-fense from predators, antimicrobial and antifungal activity [8].
Evidence of natural origin has been obtained by radiocarbon(14C) analysis of 6-OH-BDE47, 20-OH-BDE68, 20,6-diOH-BDE159,and 20-MeO-6-OH-BDE120 [51,78], and 1,10-dimethyl-3,30,4,40-
tetrabromo-5,50-dichloro-2,20-bipyrrole (DBP-Br4Cl2) [79]. Otherstudies have noted the presence of 6-MeO-BDE47 and 20-MeO-BDE68 in environmental samples that pre-dated the advent ofanthropogenic PBDEs; viz. a whale oil sample archived since 1921[80], sediment layers deposited since the late 1800s to early 1900sin the southern Yellow Sea and East China Sea [38,81] and in an
Fig. 3. Formation and transformations of bromophenolic compounds.
archivedwhite-tailed sea eagle (Haliaeetus albicilla) egg laid in 1941[82]. Fishmeal samples from worldwide sources were screened forPBDE flame retardants, MeO-BDEs and OH-BDEs [83]. Although allthree compound classes were abundant in fishmeal, there were nosignificant correlations between PBDEs and their MeO- and OH-analogs, supporting the natural origin hypothesis.
Phenols and anisoles containing bromine, chlorine, or both alsohave anthropogenic sources; for example, water chlorination[1,84e86], industrial use and hazardous waste incineration [87],and metabolism or abiotic degradation of brominated flame re-tardants [88]. The world production of 2,4,6-triBP was estimated at9500 tonnes in 2001 [87]. The 1,2,4,5-tetrachloro-3,6-dimethoxybenzene (also known as 2,3,5,6-tetrachloro-1,4-dimethoxybenzene), ubiquitous in marine air, may be a naturalproduct or a metabolite of anthropogenic organochlorines [89,90].In addition to natural sources, MeO-BDEs and OH-BDEs are pro-duced by metabolism of PBDEs [88,91,92], and OH-BDEs areelevated in water and sediments near sewage treatment plantdischarges [17,93].
Terrestrial fungi and lichens, and some insects, are sources ofsimple halocarbons and more complex HNPs [2]. Biotic and abioticprocesses leading to production of adsorbable organohalogens(AOXs) in freshwater and marine sediment have been reviewed byMüller et al. [94] and for total organically bound bromine interrestrial ecosystems by Leri and Myneni [95]. Organically boundchlorine is produced in boreal soils by chlorination of organicmatter [96]. All bromine in decaying plantmaterial, isolated humicsand the organic fraction of soils is covalently bound to carbon [95].
4. Transformation processes
Abiotic and biotic degradation pathways for BPs were summa-rized by Howe et al. [87]. OH radical reaction half-lives in air wereestimated as 13.2 h (4-BP), 44.6 h (2,4-diBP), 22.5 d (2,4,6-triBP),and 23 d (pentaBP). The EPISUITE program predicts OH radical half-lives in air of 4.1 d (2,4-diBA) and 8.5 d (2,4,6-triBA). It has beensuggested that the ubiquitous presence of OH-BDEs in precipitationis due to OH radical reaction with PBDEs [17]. Bromophenoliccompounds are transformed as shown in Fig. 3. O-methylationconverts BPs and OH-BDEs to BAs and MeO-BDEs. Cycles of O-methylation-demethylation reactions interconvert MeO-BDEs andOH-BDEs in sediment [38,97]. Transformation of BPs and MeO-BDEs to PBDDs takes place by photochemical [61,64e66], enzy-matic [60,63] and surface-catalyzed [62] reactions. Photolysis also
breaks down complex compounds. BPs with all possible sub-stitutions can be formed by photolysis of PBDEs [98]. The meta-substituted BPs distinguish this process from natural formation,which produces exclusively ortho- and para-substituted BPs.
Metabolism produces OH-BDEs fromMeO-BDEs and it has beensuggested that OH-BDEs in wildlife from remote areas arise fromdemethylation of accumulated MeO-BDEs [99]. Evidence of thisdemethylation was not seen in harbor porpoise (Phocoena pho-coena) [100] nor in ringed seal (Phoca hispida) [101], while noconclusions could be drawn for harbor seal (P. vitulina) [100]. Theopposite, conversion of 6-OH-BDE47 to 6-MeO-BDE47 has beenshown to occur in the fish Japanese medaka (Oryzias latipes) [102].Positive correlations among OH-BDEs, MeO-BDEs and 2,4,6-triBP incetaceans suggest that they may share common sources or meta-bolic pathways [103,104]. A strong correlation was found in polarbear (Ursus maritimus) adipose tissue between log-transformed 6-OH-BDE47 and 6-MeO-BDE47 (p< 0.001),
POH-BDEs and
PMeO-
BDEs (p < 0.001), and for (P
OH-BDEs þ PBPs) and
PMeO-BDEs
(p< 0.001) [99]. TheP
OH-BDEs were correlated toP
PBDEs inplasma of bald eagle (Haliaeetus leucocephalus) from BritishColumbia (Canada) and California (USA) [105]. Significant correla-tions have been found between 6-MeO-BDE47 and PBDE-47, apossible precursor, in Greenland shark (Somniosus microcephalus)[106], glaucous gull (Larus hyperboreus) [107], beluga (Delphi-napterus leucas), ringed seal and sea duck species [101]. Significantcorrelations were found between 6-MeO-BDE47 or 20-MeO-BDE68and all seven monitored PBDE congeners in muscle tissue of white-tailed sea eagle [108]. Rotander et al. [109] found that such a cor-relation was significant but weak in the marine mammals theystudied. Investigations in four species of microalgae showed nobiotransformation of PBDEs to their corresponding OH-BDEs orMeO-BDEs, and the authors suggested that algal transformation isunlikely to explain the presence of OH-BDEs and MeO-BDEs in themarine environment [110].
Many reports indicate that biotransformation of PBDEs pro-duces OH-BDEs with the OH-group meta- or para-to the diphenylether bond, whereas ortho-positioning is favored for the naturallyproduced compounds (reviewed by Wiseman et al. [111]. Thisinterpretationwas criticized by Ren et al. [112], who found hydroxygroups in the ortho-position in some OH-BDEs from an e-wasterecycling plant. PBDEs substituted with a single OH-group in thepara position are rare in marine species; however, PBDEs contain-ing one ortho-MeO-group and two OH-groups (meta- and para-)have been identified in marine sponges [6]. Only natural versusanthropogenic PBDE-derived MeO-BDEs might also be distin-guished by ortho-versusmeta-/para-substitution of the MeO-group[113]. However, since MeO-BDEs have not been identified in PBDEexposure studies, their source remains unclear and the possibilityof naturally-produced MeO-BDEs with meta-/para-substitutionshould be considered [111].
PBDDs are produced by enzyme coupling or photolysis of BPsand OH-BDEs. Enzymatic coupling of 2,4,6-triBP yielded mainly1,3,6,8-tetraBDD with lower amounts of 1,2,4,7-/1,2,4,8-tetraBDD,1,3,7,9 -tetraBDD, 1,3,7-triBDD, 1,2,7-triBDD and 2,7-/2,8-diBDD[63]. Photolysis of 6-OH-BDE47 and 20-OH-BDE68, generally themost abundant congeners, yielded themost abundant PBDDs foundin Baltic fish, viz 1,3,7- and 1,3,8-tri-BDD [64]. Photolysis of 6-OH-BDE99, 60-OH-BDE100 and 60-OH-BDE116 produced 1,2,4,8-,1,3,7,9-and 2,3,7,8-tetraBDD, respectively [66], while photolysis of 6-OH-BDE137 yielded tetraBDDs with unidentified substitution [65].Haglund et al. [114] examined congener profiles of MeO-BDEs andPBDDs in Baltic perch (Perca fluviatilis) and flounder (Platichthysflesus) in relation to lower organisms collected in the same area.MeO-BDEs without adjacent substituents (6-MeO-BDE47) or withtwo adjacent substituents (20-MeO-BDE68 and 6-MeO-BDE90)
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e11594
were retained in the fish more than MeO-BDEs with three adjacentsubstituents (6-MeO-BDE85 and 6-MeO-BDE99). For PBDDs,1,3,6,8-tetraBDD and 1,3,7,9-tetraBDD were retained more thanother PBDDs which have vicinal hydrogens. Debromination of 6-MeO-BDE85 and 6-MeO-BDE99, and cytochrome P-450 mediatedoxidation of PBDDs containing vicinal hydrogens were suggested toexplain their limited retention.
5. Concentrations and trends in the physical environment
5.1. Air and precipitation
A summary of 2,4-diBA and 2,4,6-triBA concentrations in air isshown in Fig. 4. BAs ranging from monobromo- through pentab-romo- were found on shipboard expeditions and island stations inthe Northern and Southern hemispheres in 1984, 1986, 1993e1994and 1999e2000. Concentration ranges were: <0.1e2.2 pgm�3 (2-BA); �0.1 pgm�3 (3-BA); <0.1e3.6 pgm�3 (4-BA); <0.1e17 pgm�3
The first quantitative measurement of 2,4,6-triBA in Scandina-vian air was at Lista, Norway (58.10� N, 6.57� E) in 1999, at30 pgm�3; the compound was also identified but not quantified inair from Zeppelin Mountain (Svalbard, 78.92� N, 11.88� E) andSigney Island (Antarctica, 60.72� S, 45.60� W) [118]. Other HNPsidentified were mixed halogenated compound MHC-1 and thePMBP compound Q1. The seasonal cycles of 2,4-diBA, 2,4,6-triBAand Q1 in air at Lista were investigated in 2003 [119]. Annualmean concentrations were 19± 12 pgm�3 for 2,4-diBA,13± 9 pgm�3 for 2,4,6-triBA and 0.025± 0.022 pgm�3 for Q1(±indicates standard deviation throughout the paper). Concentra-tions of 2,4-diBA and 2,4,6-triBA were low in JanuaryeApril,increased rapidly during May and were relatively stable throughDecember. Concentrations of the two BAs were approximatelyequal during the first half of the year, but 2,4-diBA dominated fromSeptember through December. Q1 showed lower levels fromFebruaryeAugust and higher levels from SeptembereJanuary. In
Fig. 4. Concentrations of 2,4-dibromoanisole (2,4-diBA) and 2,4,6-tribromoanisole (2,4,6-tAtlantic 1993 [116]; N&S Atlantic 2001 [117]; Lista, Norway [119]; Birkenes, Andøya and SvArctic [123].
comparison, anthropogenic hexachlorocyclohexanes (HCHs)showed a typical POPs concentration cycle of higher concentrationsin summere autumn and lower concentrations in winterespring.
Starting in 2007, 2,4,6-triBA was monitored in air at Birkenes insouthern Norway (58.38� N, 8.25� E) and at Zeppelin, and moni-toring was started at another Norwegian Arctic station (Andøya,69.28� N, 16.01� E) in 2010 [120]. The seasonal trends were similarto those at Lista, lower concentrations in spring and increasingduring summer and autumn. Annual mean concentrations in 2016were: Birkenes 4.2 pgm�3, Andøya 4.2 pgm�3 and Zeppelin6.5 pgm�3.
BAs in air and atmospheric deposition (rain, snow, particlefallout) were measured in archived samples collected along atemperate to Arctic gradient in Fennoscandia between 2002 and2015 [121]. Seasonal variations were similar to those observed atother stations, lower concentrations in January through March,increasing in spring and reaching a plateau from mid-summerthrough fall. Annual mean concentrations at Ra€o on the Swedishwest coast (57.39 �N, 11.91 �E) ranged from 20± 9.1 to41± 20 pgm�3 for 2,4-diBA, and 43± 20 to 74± 36 pgm�3 for2,4,6-triBA. Annual means at the inland Arctic station Pallas,Finland (68.00�N, 24.15�E) ranged from 3.7± 4.4 to 20± 23 pgm�3
for 2,4-diBA and 4.9± 5.5 to 14± 12 pgm�3 for 2,4,6-triBA. Thepartial pressures of both BAs were significantly correlated toreciprocal temperature (T/K) at the coastal site Rå€o (2,4-diBAr2¼ 0.39, p< 0.0001; 2,4,6-triBA r2¼ 0.58, p< 0.0001), but less soat the terrestrial station Pallas (2,4-diBA r2¼ 0.13, p¼ 0.002; notsignificant for 2,4,6-triBA). The difference reflects local sea-to-airexchange at Rå€o versus long-range transport contribution atPallas. No long-term trends were found at Rå€o, while a significantincrease (p¼ 0.041) was noted for 2,4-diBA at Pallas between 2002and 2015. An increase in 2,4,6-triBAwas also suggested, but was notsignificant (p¼ 0.064). Geometric mean deposition fluxes in2012e2015 were 50e73 pgm�2 d�1 (2,4-diBA) and 43e79 pgm�2
d�1 (2,4,6-triBA) at Rå€o; 33e48 pgm�2 d�1 (2,4-diBA) and30e35 pgm�2 d�1 (2,4,6-triBA) at Pallas. Deposition fluxes weresimilar at Rå€o and Pallas despite lower air concentrations at Pallas,due to greater precipitation scavenging at lower temperatures.
Intermediate air concentrations were measured in the northern
riBA) in global air. American Samoa and New Zealand [115]; Indian Ocean [89]; N&Salbard, Norway [120]; N. Baltic [122], Rå€o, Sweden and Pallas, Finland [121]; Canadian
Baltic region at islands Holm€on (HOL, 63.79� N, 20.84� E) andHaparanda Sandsk€ar (SKR, 65.57� N, 23.75� E) and at KrycklanCatchment (KRY, 64.23� N, 19.77� E), about 60 km inland [122].Mean concentrations of 2,4-diBA and 2,4,6-triBA were 23± 16 and43± 30 pgm�3 at HOL, 19± 13 and 18± 7.9 pgm�3 at SKR, and38± 19 and 23± 8.9 pgm�3 at KRY.
BAs in air of the Canadian Arctic Archipelago were measured in2007e2008 during expeditions to the Labrador Sea, Hudson Bayand the southern Beaufort Sea [123]. Overall means were15± 10 pgm�3 for 2,4-diBA and 20± 14 pgm�3 for 2,4,6-triBA.Additional samples collected in the Archipelago during 2014e2015,sampled [123] and processed [131] as before, showed mean con-centrations of 2,4-diBA¼ 6.4± 7.2 and 2,4,6-triBA¼ 9.9± 8.2 pgm�3.
Although data are limited, concentrations of BAs in Subarctic-Arctic air appear comparable to levels seen at lower latitudes(Fig. 4). Higher concentrations have been noted near coastal areas,which are biologically productive [116,121].
BPs have occasionally been sought in ambient air and depositionat Nordic stations. Concentrations of 2,4-diBP and 2,4,6-triBP in airsamples from 2001 to 2002 were <10 pgm�3 and <1 pgm�3 atPallas, Finland and the background station R€orvik on the Swedishwest coast (57.23 oN, 14.58 oE) [124]. These levels can be comparedto urban areas of southern Sweden where concentrations in thesame time period were 8e30 pgm�3. Atmospheric fluxes (rain,snow, dry particle deposition) at R€orvik were 0.8 to 4.4 ngm�2 d�1
(2,4-diBP) and 1.8 to 6.6 ngm�2 d�1 (2,4,6-triBP); with corre-sponding fluxes at Pallas of <0.3 ngm�2 d�1 (2,4-diBP) and0.6 ngm�2 d�1 (2,4,6-triBP) [124]. BPs were included among a suiteof brominated flame retardants (BFRs) in a 2009 Nordic screeningstudy [125]. Levels of 2,4-diBP and 2,4,6-triBP in background airwere 9.1 to 21 and 17 to e27 pgm�3, while pentaBP was<0.5 pgm�3, at Rå€o in 2009e2010. Corresponding concentrationsof the three BPs in Lille Valby, Denmark (55.70 oN, 12.12 oE) were6.0, 17, and <1 pgm�3, respectively. Concentrations in urban air ofStockholm, Copenhagen and Oslo were in general lower than thosein background air. BPs were measured in 2014 in air at Pallas andRå€o as part of a screening study of alternative brominated flameretardants in air [126]. The ranges in air concentration at Rå€o andPallas were 1.1e13 and 0.21e3.6 pgm�3 (2,4-diBP), 0.050 e 0.070and 0.031e0.27 pgm�3 (2,6-diBP), 0.48 e 1.6 and 0.14e1.3 pgm�3
(2,4,6-triBP), respectively. MonoBPs were measured at0.54e4.1 pgm�3 at Rå€o and 0.21e9.3 pgm�3 at Pallas for individualspecies.
Two chlorinated compounds of possible phenolic origin, androutinely monitored in Arctic air at the Canadian station Alert(82.50 oN, 62.33 oW), are pentachloroanisole (pentaCA, annualmeans 1e12 pgm�3) and tetrachloroveratrole (1,2,3,4-tetrachloro-5,6-dimethoxybenzene) (annual means 0.67e2.0 pgm�3) [127].Chloroanisoles (CAs) including pentaCA and bromochloroanisoleshave also been identified over oceans in the northern and southernhemispheres [89,90,115e117]. Concentration ranges were:<0.1e16 pgm�3 (2,6-diCA); <0.1e243 pgm�3 (2,4,6-triCA);<0.1e0.7 pgm�3 (2,3,4,5-tetraCA); <0.1e11 pgm�3 (2,3,4,6-tetraCA); 0.2e40 pgm�3 (pentaCA); 1.6e5.7 pgm�3 (2,4-dibromo-6-chloroanisole) and 0.6e2.5 pgm�3 (2,6-dibromo-4-chloroanisole) [89,116,117]. Another chlorophenolic compoundfound in marine air is 1,2,4,5-tetrachloro-3,6-dimethoxybenzene(also known as 2,3,5,6-tetrachloro-1,4-dimethoxybenzene), not tobe confused with the tetrachloroveratrole mentioned above. Con-centrations of 1,2,4,5-tetrachloro-3,6-dimethoxybenzene in marineair were 2e96 pgm�3 over the North and South Atlantic oceans[90] and 20e280 pgm�3 at R�eunion [89]. It is not known whetherthe CAs and related compounds are natural, formed from anthro-pogenic phenols, or both (see discussion of pentaCA sources and
distribution [128,129]. Higher concentrations of CAs were found inthe Northern Hemisphere than the Southern Hemisphere, sug-gesting anthropogenic origins [90,116]. In contrast, BAs werehighest near upwelling zones off the coast of Africa [116,117]. Thetetrachloroveratrole found in air at Alert may have origins in thechlorine bleaching process used for pulp and paper [130].
No data on MeO-BDEs in Arctic air are available. Mean con-centrations of 0.017± 0.016 pgm�3 (20-MeO-BDE68) and0.014± 0.014 pgm�3 (6-MeO-BDE47) were found in gas-phase airsamples collected over the northern Baltic Sea in 2011e2013 [131].These levels are much lower than those reported for the
P6 tri-
bromo- andP
6 tetrabromo-MeO-BDEs in air (gas phase) of Busan(South Korea) in 2010e2011 (means 2.1± 1.8 and 6.9± 8.7 pgm�3,respectively, with comparable concentrations in the particle phase)[14]. OH-BDEs were below detection in the Korean air samples. OH-BDEs were found in rain and snow collected in southern Ontario(Canada), where deposition fluxes for
P23 OH-BDEs ranged from
3.5 e 190 pgm�2 day�1 [17]. Many of the compounds were struc-turally unidentified. Of the 18 OH-BDEs that were identified byauthentic standards, the more abundant ones were 3-OH-BDE47, 5-OH-BDE47, 6-OH-BDE47, 40-OH-BDE49, 6-OH-BDE85, 4-OH-BDE90,6-OH-BDE90 and 6-OH-BDE99. Mean deposition fluxes of
P23OH-
BDEs were about 10% ofP
6-14PBDEs. OH-BDEs were also found instream and lake water. It was suggested that the OH-BDEs weremost likely produced by OH radical reactions with atmosphericPBDEs, although some of the identified congeners were also knownto have biogenic sources (e.g., 6-OH-BDE47, 20-OH-BDE68, 6-OH-BDE90, 6-OH-BDE137).
5.2. Seawater and marine sediments
Very few measurements have been reported for HNPs inseawater, although halocarbons such as CHBr3, CH2Br2, CHBr2Cl andCH2ICl are widespread and abundant [132]. Hot spots for halocar-bons in the Arctic are productive shelf areas and surfacewaters overthe Makarov and Lomonosov ridges, which receive dissolvedorganic matter (DOM) from river water transported in the Trans-polar Drift, and they are also produced in sea ice brine. There havebeen no investigations of whether higher molecular weight HNPsare also associated with these geographic features.
Available data for BAs in seawater worldwide are summarized inFig. 5. BAs were measured in surface water on expeditions acrossthe Canadian Arctic Archipelago and the southern Beaufort Sea in2007e2008 [123]. Mean concentrations in the southern BeaufortSea off Banks Island were 8.8± 7.7 pg L�1 (2,4-diBA) and10.2± 8.1 pg L�1 (2,4,6-triBA). Higher concentrations were found inHudson Bay and Hudson Strait (19± 3.3 and 34± 0.7 pg L�1) andthe Labrador Sea (38± 14 and 163± 32 pg L�1). Additional samplescollected in the Archipelago during 2014e2015, sampled [123] andprocessed [131] as before, showed mean concentration of 2,4-diBA28± 13 and 2,4,6-triBA 13± 2 pg L�1.
It is possible that BAs in Arctic seawater may have arrived via airor ocean current transport from lower latitudes, but the widevariation in concentrations, differing compound proportions andidentification of biogenic sources in Antarctica [11] suggest localproduction. Concentrations of BAs in Arctic seawater are lower thanthose reported for the northern and southern Baltic Sea (2,4-diBA86± 51 pg L�1, 2,4,6-triBA 199± 150 pg L�1) [131], Atlantic Ocean(2,4-diBA 73 pg L�1, 2,4,6-triBA 128 pg L�1) [117] and on the GreatBarrier Reef, Australia (2,4-diBA 21e1370 pg L�1, 2,4,6-triBA6e3280 pg L�1) [133,134] (see also below).
To our knowledge, no data are available for BPs in Arctic Oceanwater. They were identified in water of the North Sea along withbromoindoles [135]. Reineke et al. [136] quantified BPs and bro-moindoles in water from the German Bight at concentrations of
Fig. 5. Concentrations of 2,4-dibromoanisole (2,4-diBA) and 2,4,6-tribromoanisole (2,4,6-triBA) in sea and ocean water. Baltic Sea [131]; N&S Atlantic [117]; Great Barrier Reef [134];Hudson Bay, Labrador Sea, Banks Island (Canadian Archipelago) [123].
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e11596
2e48 ng L�1 (2,4-diBP), and not detected (ND) to 5 ng L�1 (2,4,6-triBP), 15e1390 ng L�1 (sum of dibromoindoles) and<1e2370 ng L�1 (tribromoindole). Dahlgren et al. [37] identified2,4,6-triBP at 360 pg L�1 in water from the Swedish west coast and180 pg L�1 in water from the Stockholm Archipelago. BPs werecollected from seawater on the Great Barrier Reef by semiperme-able membrane devices (SPMDs), and showed orders of magnitudevariation in concentrations, 23e28900 pg L�1 for 2,4-diBP,NDe2370 pg L�1 for 2,6-diBP and NDe320 pg L�1 for 2,4,6-triBP(detection limits not specified) [134]. BPs in seawater off thecoast of South Korea ranged from 0.53e32.7 ng L�1 for 2,4-diBP and0.38e20.2 ng L�1 for 2,4,6-triBP [85]. Chlorination of water from anuclear power plant may have led to production of observedchlorophenols, as well as enhancement of BP levels over naturalformation.
Over 2000 organobromine and organoiodine compounds (nat-ural and synthetic) were found in Arctic Ocean sediments collectedon a transect from the Bering Sea across the Northwest Passage toIceland, as well as in Lake Michigan (U.S.A.) [15,16]. Compoundsincluded the bromo-and iodophenolic compounds, bromocarba-zoles and many others which had not been previously beendetected. Iodophenol, long-chain iodophenols and iodoindole wereprominent. Iodoindoles were about 10 times more abundant thanbrominated ones. The diversity of HNPs in Arctic Ocean sedimentswas greater than in Lake Michigan.
BPs arewidespread in temperate marine sediments, especially ifthey contain infauna which produce them [49,50,53]. Concentra-tions in sediments from harbor sites in the Faroe Islands were0.79e2.9 ng g�1 dry weight (dw) (2,4-diBP), 0.47e7.8 ng g�1 dw(2,4,6-triBP) and <0.02e0.0027 ng g�1 dw (2,4,6-triBA), whileranges for other impacted areas in Denmark, Norway and Finlandwere <0.07e1.7 ng g�1 dw (2,4-diBP), <0.02e4.8 ng g�1 dw (2,4,6-triBP) and <0.02 to 0.66 for 2,4,6-triBA [125]. Concentrations inNorth Sea sediments were 5e360 ng g�1 (dw) for 4-BP,0.3e43 ng g�1 dw for 2,4-diBP, and 0.4e110 ng g�1 dw (sum ofdibromoindoles) [136]. BPs in sediments off the coast of SouthKorea ranged from 0.62 to 7.7 ng g�1 dw (2-BP), 5.6e57.0 ng g�1 dw(3-BP), 76.3e530 ng g�1 dw (4-BP), 1.6e9.6 ng g�1 dw (2,4-diBP),0.81e24.0 (2,6-diBP) and 0.56e12.3 ng g�1 (2,4,6-triBP), and. tri-chlorophenols was also found [85].
MeO-BDEs and OH-BDEswere not found in sediments of easternHudson Bay or Hudson Strait in the Canadian Arctic Archipelago,sampled 1999e2003, at detection limits of 0.001e0.004 ng g�1 dw
[101], and they have not been reported in Arctic seawater. MeO-BDEs were determined in northern Baltic seawater in2011e2013 at mean concentrations of 25± 17 pg L�1 (6-MeO-BDE47) and 8.2± 5.9 pg L�1 (20-MeO-BDE68) [131]. 6-OH-BDE47and 20-OH-BDE68 were found in water from the Stockholm Archi-pelago at concentrations of 420 and 90 pg L�1, respectively [37]. 6-OH-BDE85, 6-OH-BDE90 and 6-OH-BDE99 were also detected, butwere too low to be quantified. All OH-BDEs were below thedetection limit (not specified) on the Swedish west coast [37].
Water samples were passively collected on the Great BarrierReef using SPMDs in 2007e2008 [133] and from2007 to 2013 [134].Estimated mean concentrations of HNPs over the 6-year periodwere: 2,4-DiBA 450 pg L�1, 2,4,6-triBA 170 pg L�1, 20-MeO-BDE6815 pg L�1, 6-MeO-BDE47 30 pg L�1, 20,6-diMeO-BDE68 10 pg L�1,2,20-dimethoxy-3,30,5,50-tetrabromobiphenyl (2,20-MeO-BB80)4.0 pg L�1 [134]. Monitoring from 2007e2013 showed strong sea-sonal and interannual variations in these compounds, as well as BPsand PDBPs [134]. Seawater and sediments were sampled from thesouthern coast of South Korea in 2015 [137]. Average concentra-tions of
P17MeO-BDEs and
P8OH-BDEs were 1.03 and 7.4 pg L�1 in
seawater, and 0.367 and 0.324 ng g�1 dw in sediments. Individualcongeners were not specified, but ortho-substituted OH-BDEs andMeO-BDEs were predominant offshore, whereas meta-substitutedcompounds were in greater abundance in river water and soil. Thedifference was suggested to be due to natural production offshoreversus transformation of PBDEs inland. Twelve MeO-BDEs and 11OH-BDEs were sought in marine sediments and the food web ofLiaodong Bay, Bohai Sea, China [97]. The congeners found in sedi-ment were 4-MeO-BDE17, 6-MeO-BDE17, 5-MeO-BDE47, 6-MeO-BDE47, 20-MeO-BDE68, 40-MeO-BDE101, 6-OH-BDE47 and 20-OH-BDE47. Congeners 3-OH-BDE47, 5-OH-BDE47 and 4-OH-BDE49were found in some biota. Occurrence of these meta-/para-substituted congeners may have resulted from biotransformationof PBDEs. Concentrations of the
P12 MeO-BDEs and
P10 OH-BDEs
in marine sediments of Liaodong Bay, Bohai Sea, China were0.0038e0.056 ng g�1 dw and 0.0032e0.116 ng g�1 dw, respectively,with the most abundant congeners being 20-MeO-BDE68, 20-OH-BDE68, 6-MeO-BDE47, and 6-OH-BDE47 [97]. Interconversion be-tween OH-BDEs and MeO-BDEs was demonstrated. Concentrationsof MeO-BDEs in surface sediment and cores from the East China Searanged from 0.0198e0.0477 ng g�1 dw (20-MeO-BDE68) and0.0187e0.0912 ng g�1 dw (6-MeO-BDE47) [38]. OH-BDEs rangedfrom 0.0105e0.0211 ng g�1 dw (20-OH-BDE68) and
0.0129e0.0839 ng g�1 dw (60-OH-BDE47). A similar study in theYellow Sea showed concentrations ranging up to 0.083 ng g�1 dw(20MeO-BDE68), 0.173 ng g�1 dw (6-MeO-BDE47), 0.083 ng g�1 dw(20-OH-BDE68) and 0.246 ng g�1 dw (6-OH-BDE-47), and 3-MeO-BDE47 was also found up to 0.044 ng g�1 dw [81]. In both seas,these compounds were found in deep sediment layers that pre-dated the advent of PBDE flame retardants. In the East China Seacores, levels of MeO-BDEs and OH-BDEs were correlated withphytoplankton lipids, suggesting natural production. In support ofthis, 20-MeO-BDE68 and 6-MeO-BDE47 were found in incubatedmicroalgae species [38]. In a core collected from the shelf area ofthe East China Sea, surface concentrations of 6-MeO-BDE47,P
MeO-/OH-BDEs and total organic carbon were higher thandowncore levels, suggesting terrigenous inputs from PBDE trans-formation [138].
PDBPs were examined in the Arctic food web of the NorthwaterPolynya in the eastern Canadian Arctic (76�N to 79�N and 70�W to80�W) during 1998 (Section 9), and sediments were included [25].Mean concentrations ranged from <0.002 ng g�1 dw for DBP-Br5Clto 0.028 ng g�1 dw for DBP-Br6.
PBDDs have not been reported in sediment or seawater from theArctic. Seven tetrabromo- and 8 tribromo-PBDDs were identified(but not quantified) in sediments from the Baltic Proper [114], andthe same congeners were also found in algae (Section 6.1), mussels(Mytilus edulis) (Section 6.2) and perch (Perca fluviatilis) (Section6.3.1.6) [114,139]. Brominated and chlorinated dioxins and furanswere quantified in surface sediments off Hong Kong and Korea[140]. The
PPCDDs and
PPCDFs exceeded their brominated ana-
logs. Concentration ranges (ng g�1 dw) (tetra-to octachloro- orbromo-, congeners not specified) were Hong Kong: 2.4e6.0(P
PCDDs), 0.071e0.30 (P
PCDFs), 0.006e0.043 (P
PBDDs),0.006e0.021 (
PPBDFs); Korea: 0.090e0.68 (
PPCDDs), 0.052e0.70
(P
PCDFs), NDe0.009 (P
PBDDs), NDe0.46 (P
PBDFs) (detectionlimits not specified). Monobromo-PCDDs were also determined.Although some dioxin-furan contamination may be due to naturalproduction, industrial sources, disposal of flame retardants andcombustion of e-waste is likely.
PBDDs and PBDFs were determined in dated sediment coresfrom Tokyo Bay [141]. Concentrations of
PPBDDs in surface sedi-
ments ranged from 2.2e17 ng g�1 dw and showed little variation inthe core slices from 1895 to 1998e2000, whereas
PPBDFs ranged
from 21e60 ng g�1 dw at the surface and decreased to belowdetection by 1943e1975, depending on the core. Downcore trendsof PBDEs and PBDFs were similar, suggesting contamination oftechnical PBDE formulations (especially deca-BDE) with PBDFs.Lack of a trend for PBDDs and their presence before the industrialera supports their natural formation.
5.3. Sea-air exchange
Sea-air exchange of BAs in the Canadian Archipelago [123] hasbeen estimated using concentrations in surface seawater and air,employing the Henry's law constants (dimensionless, KAW) re-ported by Pfeifer et al. [142] (Table S1). Net fluxes (depositionminus volatilization) estimated by the Whitman two-film modelwere small and variable: e1.2± 0.69 (2,4-diBA) ande0.46± 1.1 ngm�2 d�1 (2,4,6-triBA). Later, experimental measure-ments of KAW for 2,4-diBA and 2,4,6-triBA were made as functionsof temperature [131] (Table S1). The new KAW values were used hereto reassess the gas exchange of BAs in Hudson Bay and the southernBeaufort Sea, based on the 2007e2008 air and water data [123],with the result that 2,4,6-triBA was near air-water equilibrium,while 2,4-diBAwas near equilibrium or undergoing net deposition.A larger departure from equilibrium was found in Bothnian Bay,northern Baltic Sea, where net volatilization fluxes between May
and September were first estimated ase12 toe44 ngm�2 d�1 (2,4-diBA) and e54 to e310 ngm�2 d�1 (2,4,6-triBA) using the Pfeiferet al. [142] KAW values [143,144], and cumulative net volatilizationof
PBAs from Bothnian Bay from May to September was e1319 kg
[131]. With the newer KAW values [131], volatilization fluxes fromthe northern Baltic were lowered to about half the previous esti-mates and net volatilization of
PBAs from the bay was reduced to
e532 kg [131]. Outgassing of BAs from the temperate and tropicalAtlantic Ocean has also been reported, but fluxes were not quan-tified [117].
The compounds tetrachloro-1,4-dimethoxybenzene and penta-chIoromethoxybenzene (pentachloroanisole, pentaCA) may haveboth natural and anthropogenic sources. Hemispheric differencesin net exchange direction were found. The South Atlantic was closeto air-water exchange equilibrium for these compounds, whereasthe North Atlantic was undersaturated, especially in areas receivinginput from continental air [90].
Sea-air exchange was estimated for MeO-BDEs in Bothnian Bay,based on limited air and water concentration data (Section 5.2) anda value of KAW for 6-MeO-BDE47 estimated from the KAW of BDE47[131]. Net exchange directions for 20-MeO-BDE68 and 6-MeO-BDE47 were predicted to be sea-to-air, but depended greatly on thebinding of the MeO-BDEs to DOM.
Several brown algae species on the west coast of Ireland (MaceHead) have been found to emit molecular iodine, oxidized iodinespecies and iodocarbons to the atmosphere at concentrations suf-ficient to perturb ozone levels [145]. These findings raise thequestion whether volatile HNPs could also be emitted from inter-tidal algae beds.
5.4. Terrestrial environment, inland waters
The few measurements of inorganic bromine in terrestrial soilsrange from 5e40mg kg�1, which is smaller than in marine sedi-ments, where concentrations can exceed 100mg kg�1 [95]. None-theless, haloperoxidase enzymes extensively convert inorganicbromine to organic forms in terrestrial plants and X-ray absorptionnear edge structure (XANES) spectroscopic studies show that all thebromine in isolated humic substances, decaying plant material, andthe organic fraction of soils is covalently bonded to carbon [95].There are also many anthropogenic sources of organobrominecompounds in the terrestrial environment, including flame re-tardants [146] and combustion processes [147]. Over 3000 naturaland synthetic compounds containing bromine and iodine werefound in sediments of Lake Michigan (U.S.A.) [15,16].
No reports were found for most high molecular weight HNPs inArctic-Subarctic soils or plants, although Arctic-Subarctic soils canbe both sources and sinks for halocarbons [148e150]. 2,4-DiBA and2,4,6-triBA were measured in tundra streams near Abisko, Sweden(68.35 oN, 18.83 oE) at concentrations ranging from <6e50 pg L�1
and 6.3e64 pg L�1, respectively [151]. BPs were determined inmossaround two incinerator facilities on the Faroe Islands in 2009 [125].Levels ranged from <0.3e0.53 ng g�1 dw (2,4-diBP),<0.1e0.46 ng g�1 dw (2,4,6-triBP) and 0.0074e0.0086 ng g�1 dw(2,4,6-triBA). Two soil samples from Gårdsj€on research forest insouthern Sweden contained <3e15 ng g�1 dw (2,4-diBP) and2e5 ng g�1 dw (2,4,6-triBP) [124].
Although biogenic MeO-BDEs are mainly discussed in associa-tionwith the marine environment, there may be terrestrial sourceswhich have not yet been clarified. To our knowledge, there are nopublished studies of MeO-BDEs or OH-BDEs in Arctic soil, lakesediments or water. MeO-BDEs and OH-BDEs have been found insoil, pine needles and air (Section 5.1) near Busan, South Korea [14].Several studies have found OH-BDEs and/or MeO-BDEs in water/sediment of inland rivers and lakes [13,14,17,137,152,153]. A likely
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e11598
source of these compounds is sewage treatment plants, since OH-BDEs have been found in association with them [17,93]. Chemicalstructures were determined for over 2000 brominated and iodatedcompounds in Lake Michigan sediments [15,16]. Compoundsincluded the bromophenolic compounds, bromo-and iodocarba-zoles and many others which had not been previously identified.Carbazoles containing bromine, chlorine and mixed halogens werefound in lake and river sediments in the North American GreatLakes region [154].
PentaCP and pentaCA are discussed briefly below and in moredetail by Kylin et al. [128,129]. PentaCA has been extensivelyinvestigated in air and vegetation andwas thought to be primarily ametabolite of the pentaCP wood preservative. However, a recentstudy casts doubt on this [128,129]. Examination of an extensivedataset of Eurasian and Canadian pentaCP and pentaCA concen-trations in pine needles revealed that pentaCP was higher nearsuspected point sources, whereas pentaCA showed a northern orcoastal distribution. The two compounds are poorly correlated,with pentaCP dominating in temperate North America and Europe,and pentaCA dominating in the Arctic. Anthropogenic versus nat-ural origins of pentaCA are unclear. A possible natural source ischlorination of organic matter in boreal forest soils, enhanced bymarine chloride deposition.
6. Concentrations of bromophenolic compounds, marinebiota
Total organically bound bromine is abundant in marine biotaand greatly exceeds the contributions from identified compounds.Wan et al. [155] examined tuna (Katsuwonus pelamis), five albatrossspecies (Phoebetria palpebrate and Thalassarche spp.) and polar bear(Ursus maritimus), and found that known natural bromophenoliccompounds MeO-BDEs, OH-BDEs and BPs accounted for only0.08e0.11% of total extractable organic bromine (EOBr). Brominatedfatty acids were suspected to be predominant compounds. BPs, BAs,MeO-BDEs, OH-BDEs and PBDDs (Figs. 1 and 3) are the mostfrequently reported HNPs in marine biota. They are consideredseparately here, and other HNPs follow in Section 7.
6.1. Marine vegetation
The bromophenolic compound 2,3-dibromo-4,5-dihydroxybenzyl alcohol (lanosol) was identified in the red algaPolysiphonia arctica (collected from Kongsfjorden, Spitzbergen) inresponse to oxidative stress by H2O2 [156]. Neither OH-BDEs norMeO-BDEs were found in the brownmacroalga Fucus gardneri fromeastern Hudson Bay at detection limits of 0.06e0.2 ng g�1 (lw)[101]. No other reports of HNPs in Arctic macrophytes were found.
BPs, BAs, OH-BDEs, MeO-BDEs and PBDDs have been identifiedin macroalgae (Ceramium tenuicorne, Dictyosiphon foeniculaceus,Polysiphonia fucoides, Pilayella littoralis) and phytoplankton(Nodularia spumigena, Aphanizomenon flosaquae) from the BalticSea [37,43e46,139,157], but quantified in only some of these spe-cies. Median concentrations of 2,4-diBP, 2,4,6-triBP, 2,4-diBA and2,4,6-triBA in the brown alga Dictyosiphon foeniculaceus from theBaltic Proper were 21, 180, 13 and 92 ng g�1 of extractable organicmatter (EOM), which was 0.25% of wet weight (ww) [43]. 6-OH-BDE47, 20-OH-BDE68, 6-OH-BDE85, 6-OH-BDE90, 6-OH-BDE99, 2-OH-BDE123, 6-OH-BDE137 and their MeO-analogs were alsoquantified. The
P7 median concentrations of OH-BDEs and
P7
median concentrations of MeO-BDEs were 2170 and 172 ng g�1
EOM, respectively. These summed concentrations in the EOM ofcyanobacterium Nodularia spumigena were 29 and 4.0 ng g�1.
Eighteen species of brown, green and red algae from thenorthern Baltic, Swedish west coast, and coastal region of central
Norway were analyzed for BAs and MeO-BDEs [158]. Compoundsquantified were 2,4-diBA, 2,4,6-triBA, 20-MeO-BDE68, 6-MeO-BDE47, one structurally unidentified tetrabromo-MeO-BDE and twostructurally unidentified tribromo-MeO-BDEs. Severalpentabromo-MeO-BDEs were also identified, but levels were toolow for quantification. Concentrations ranged over several orders ofmagnitude, from 0.057e58 ng g�1 ww for
P2BAs and
<0.010e0.49 ng g�1 ww forP
5MeO-BDEs. Higher concentrationsof BAs were generally found in the brown algae.
In a pioneering study, Pedersen et al. [159] identified severalsimple BPs in macroalgae species from the families Ceramiaceae,Delesseriaceae, Bonnemaisoniaceae, Rhodophyllaceae, Corallinaceaeand Rhodomelaceae. collected on the Swedish west coast. Lanosol(2,3-dibromo-4,5-dihydroxybenzyl alcohol) was also identified inseawater.
Themean concentrations ofP
14 di-, tri-, and tetrabromo-PBDDswere 18 ng g�1 EOM in the brown alga D. foeniculaceus and7.7 ng g�1 EOM in N. spumigena from the Baltic Sea [43]. Earlier,mean concentrations of 18000 ng g�1 EOM (10 ng g�1 ww) ofP
7OH-BDEs and 580 ng g�1 EOM (0.36 ng g�1 ww) ofP
4MeO-BDEs were reported in the red alga C. tenuicorne, also from theBaltic Proper [46]. BPs, BAs, OH-BDEs and MeO-BDEs showedstrong seasonal concentration fluctuations in C. tenuicorne, withhigher concentrations in Julye August, and lower concentrations inJune and September [37], and biosynthesis of OH-BDEs correlatedwith photosynthetic pigments [157]. Main PBDD congeners inC. tenuicorne were 1,3-diBDD, 2,7/2,8-diBDD,1,7-diBDD, 1,8-diBDD,1,3,7-triBDD,1,3,8-triBDD and an unidentified tetraBDD [43], whichwere also the dominant congeners in fish and mussels from theBaltic Proper (Sections 6.2 and 6.3) [139].
Production of HNPs by macroalgae and phytoplankton intemperate and tropical ecosystems is well documented. A pio-neering survey by Whitfield et al. [47] quantified BPs in 49 speciesof brown, green and red macroalgae from eastern Australia. TotalBPs across species ranged from 0.9e2590 ng g�1 ww. BPs, BAs, OH-BDEs and MeO-BDEs were found in 15 genera of brown, green andred macroalgae and angiosperms from Luzon Island, Philippines(16.57 oN, 121.26 oE) [42]. Concentrations of 2,4,6-triBP and 2,4,6-triBA ranged from 0.3e107 ng g�1 ww and <0.02e2.2 ng g�1 ww,respectively. Concentrations of 6-OH-BDE47 and 20-OH-BDE68,when detectable, ranged from 0.1e91 ng g�1 ww (<0.02 ng g�1 wwin 4 species) and 0.1e25 ng g�1 ww (<0.02 ng g�1 ww in 5 species),while concentrations of 6-MeO-BDE47 and 20-MeO-BDE68 were0.05e29 ng g�1 ww (<0.02 ng g�1 ww in 3 species) and0.1e229 ng g�1 ww (<0.02 ng g�1 ww in 4 species). Other bromo-phenolic compounds quantified were 20,6-diOH-BDE68, 20,6-diMeO-BDE68, 2,20-diOH-BB80 and 2,20-diMeO-BB80. Many otherstudies, documenting a plethora of brominated HNPs in marinealgae, were reviewed by Lin and Liu [39] and Liu et al. [40]. Halo-genated indoles containing Cl, Br, I, and sometimes two or three ofthese, were found in the red alga Rhodophyllis membranacea fromNew Zealand waters [48].
6.2. Marine invertebrates
HNPs are produced by many marine invertebrates (Section 3).Here we discuss only those that accumulate and do not produceHNPs, to our knowledge. Low bioaccumulation of BPs is expectedbecause of their low KOW values (Table 2) and dissociation atseawater pH. BAs are neutral and have slightly higher KOW (Table 2)and therefore higher bioaccumulation potential [142]. Nonetheless,concentrations of BPs were similar or higher than those of BAs inthe Baltic blue mussel (Mytilus trossulus�Mytilus edulis) from theBaltic Proper, as well as Kattegat and Skagerrak (probably Mytilusedulis) on the Swedish west coast, sampled in 2008 [43]. Mean
concentrations at the three stations were in the range2.4e16 ng g�1 EOM (2,4-diBP), 11e28 ng g�1 EOM (2,4,6-triBP),<0.2e3.5 ng g�1 (2,4-diBA), and 1.9e46 ng g�1 EOM (2,4,6-triBA).Pooled samples of blue mussel collected from 10 stations in theBaltic Proper in 2011e2012 contained 0.56e44 ng g�1 lw (2,4-diBP), 17e240 ng g�1 lw (2,4,6-triBP), 0.33e5.3 ng g�1 lw (2,4-diBA), and 5.2e66 ng g�1 lw (2,4,6-triBA) [160]; again, higherconcentrations of BPs than BAs. Possibly this reflects BPs> BAs inBaltic water, although no measurements of both have been made.Blue mussels collected from the Danish Straits region of thesouthern Baltic Sea between 2007 and 2012 contained 2,4,6-triBAat concentrations of 1.0e8.3 ng g�1 lw [22]. Amphipods (Gamma-rus sp.) from the Stockholm Archipelago (Baltic Proper) collected in2013 contained the following concentrations of BPs and BAs in ngg�1 EOM: 2,4-diBP 194, 2,4,6-triBP 2440, 2,4-diBA ND, and 2,4,6-triBA 68 [161].
BPs were included among a suite of brominated flame re-tardants (BFRs) in a 2009 Nordic screening study [125]. Blue mus-sels from urban sites in Norway contained 34e57 ng g�1 lw 2,4-diBP, 500e765 ng g�1 lw 2,4,6-triBP and 37.8e40.6 ng g�1 lw2,4,6-triBA, while concentrations at an unspecified site in Icelandwere 4.3 ng g�1 lw 2,4-diBP, 457 ng g�1 lw 2,4,6-triBP and 20 ng g�1
lw 2,4,6-triBA.2,4,6-TriBA was found in invertebrates sampled in 2003 along
the Norwegian coast [162]. Periwinkle (Littorina littorea) fromSklinna (65.20 oN, 11.00 oE) contained 0.50 ng g�1 ww, and therange in blue mussel from the Trondheim Fjord at Munkholmen(63.45 oN,10.38 oE) and Ekne (63.40 oN,11.04 oE) was 1.6e9.8 ng g�1
ww. 2,6-DiBAwas found at Ekne at 0.49 ng g�1 ww. BPs or BAs havenot been reported in other Arctic/Subarctic invertebrates. Concen-trations of 2,4,6-triBA in Antarctic krill (Euphausia superba) were57e398 pg g�1 lw [163]. Several species of Antarctic sponge con-tained BPs and BAs produced by them (2,4-diBP, 2,4,6-triBP andtheir corresponding BAs) [11].
Geometric mean concentrations ofP
10MeO-BDEs andP
15PBDEs were 14 and 5.4 ng g�1 lw respectively in blue mussel(Mytilus edulis) from eastern Hudson Bay (64.25 oN, 113.12 oW) inthe Canadian Arctic, sampled between 1999e2003 [101]. Predom-inant congeners were 6-MeO-BDE47 (2.3e34 ng g�1 lw) and 20-MeO-BDE68 (0.8e10 ng g�1 lw). Other MeO-BDEs found were 20-MeO-BDE28, 60-MeO-BDE49 and 60-MeO-BDE66. OH-BDEs werenot found at detection limits of 0.06e0.2 ng g�1 lw.
6-OH-BDE47, 20-MeO-BDE68, 6-MeO-BDE85, 6-OH-BDE90, 6-OH-BDE99, 2-OH-BDE123, 6-OH-BDE137 and their MeO-analogswere quantified in blue mussel from the Baltic Proper, Kattegatand Skagerrak [43]. The mean concentrations of
P7OH-BDEs at the
three sites ranged from 8.6e200 ng g�1 EOM, while the range formean concentrations of
P7MeO-BDEs was 12e670 ng g�1 EOM. A
subsequent study in the Stockholm Archipelago showed largeseasonal variations [164]. The
P7OH-BDEs and
P7MeO-BDEs in
mussels ranged from 160e3500 ng g�1 lw and 160e420 ng g�1 lw,respectively, between May and October. Blue mussels from theBaltic Proper, collected in 2011e2012, contained
P7OH-BDEs and
P7MeO-BDEs in the ranges 17e1500 ng g�1 lw and 17e220 ng g�1
lw, while theP
7PBDEs ranged from 3.0e18 ng g�1 lw [160]. Thesum of 20-MeO-BDE68, 6-MeO-BDE47 and 2,20-diMeO-BB80 in bluemussels from the Danish Straits ranged from 1.6e7.0 ng g�1 lw [22].Asplund et al. [165] hypothesized that Baltic blue mussels andbirds/fish that prey upon them are highly exposed to the OH-BDEsin decomposing filamentous macroalgae. Gammarus sp. from theStockholm Archipelago, contained
P7OH-BDEs 625 ng g�1 EOM
and 170 ng g�1 EOMP
7MeO-BDEs [37].The above reported concentrations of OH-BDEs in blue mussels
do not include OH-BDEs that are conjugated with lipids. This poolof OH-BDEs was recently discovered in mussels from the Baltic Sea
using non-routine analytical methods, and can be equal to or higherthan the unconjugated parent compounds [166]. The mussels alsocontained water-soluble conjugates, viz with sulfates or glucuronicacid. Thus, conventional analytical methodsmay underestimate thetotal burden of OH-BDEs in mussels.
The freshwater sponge Ephydatia fluviatilis, collected from Bor-gholmHarbor on the island €Oland, Baltic Proper (56.88 �N,16.65 �E)in 2007, contained 55 ng g�1 EOM 20-MeO-BDE68 and 93 ng g�1
EOM 6-MeO-BDE47, while PBDE47 was 4.7 ng g�1 EOM [55]. Pro-duction of MeO-BDEs inmarine sponges is well known, particularlyin Dysidea granulosa and Lamellodysidea herbacea [6,7], but thefreshwater sponge E. fluviatilis does not appear to be a large source.It was noted that levels of MeO-BDEs and PBDDs (see below)relative to PBDE47 were about the same in E. fluviatilis and musselscollected from the same area, both filter-feeding organisms.
The decabrominated compound 6-OH�60-MeO�BDE194 wasidentified in blue mussels from Kattegat and Skagerrak on theSwedish west coast [167]. Mean concentrations at the two siteswere 3700 ng g�1 lw and 410 ng g�1 lw, respectively. The sources of6-OH�60-MeO�BDE194 remain unidentified. The compound hasnot been found in any of the macroalgae species examined from theSwedishwest coast, and the authors state the high levels inmusselsmake it unlikely to be a metabolite of PBDEs.
Blue mussel from Munkholmen, Norway contained0.15e0.48 ng g�1 ww 20-MeO-BDE68 while 6-MeO-BDE47 wasfound only at Ekne, Norway at 0.28 ng g�1 ww. Periwinkle fromSklinna, Norway contained 0.042 ng g�1 ww of each MeO-BDE[162].
PBDDs have not been reported in Arctic invertebrates. PBDDswith 2e4 bromines were identified in blue mussels from the BalticProper, Kattegat and Skagerrak with mean concentrations ofP
14PBDDs 340, 20 and 2.9 ng g�1 EOM, respectively, and 1,3,8-triBDD the dominant congener in all three locations [43,168]. Inanother study [139], one composite of blue mussel tissue from theBaltic Proper contained 4.1 ng g�1 ww of
P10 PBDDs, while con-
centrations were far lower in mussel (0.024 ng g�1 ww), crab (sp.unspecified) (0.010 ng g�1 ww) and shrimp (sp. unspecified)(0.0019 ng g�1 ww) from the Swedish west coast. The
P10 PBDDs
consisted almost entirely of di- and triBDDs with tetraBDDs lowerby three orders of magnitude. Main congeners found in musselwere those found in macroalgae (Section 6.1). Increasing concen-trations in mussel from 1995 to 2003 were noted at the Baltic site.Toxic equivalents (TEQ), estimated from PBDD congener concen-trations and their reported relative potencies, were close to orexceeded the European Union maximum residue limits for PCDD/Fs.
TheP
11PBDDs was 145 ng g�1 EOM in the freshwater spongeEphydatia fluviatilis [55]. The two most abundant congeners were1,3,7-triBDD and 1,3,8-triBDD, and mixed chloro-bromo-DDs werealso identified. Polybrominated dibenzofurans (PBDFs) were absentor much lower than PBDDs, which suggests biogenic origin,although both PBDDs and PBDFs are released by combustion pro-cesses [147,169].
Several shellfish species from U.K. waters contained twoprominent PBDD congeners, 2,3,7-triBDD and 2,3,8-triBDD [170].Median levels of the two summed congeners were: Pacific oyster(Crassostrea gigas) 0.42 pg g�1 ww, native oyster (Ostrea edulis)5.33 pg g�1 ww, mussel (Mytilus edulis) 0.15 pg g�1 ww, scallop(Pecten maximus) gonad 0.36 pg g�1 ww, cockle (Cerastodermaedule) 0.02 pg g�1 ww. PBDFs (including 2,3,7,8-substituted) werealso found at “significant levels”, leading the authors to suggest thatcombustion as well as natural sources were responsible for thecontamination.
Fig. 6. Bromophenolic compounds in marine biota from Arctic, Subarctic and Balticregions. Bars indicate the 25e75% percentiles, while vertical lines show the range.Yellow triangles mark the geometric means. Red triangles on the marine mammalsgraph show the single report for
PBPs-BAs and the mean of two reports for
PPBDDs.
Concentrations in ng g�1 lw are from Tables S2, S3 and S4, and included blood, plasma,muscle, egg, liver and whole-body, as reported. In cases where concentrations werereported only in ww and no lipid information was given, lipid percentages wereassumed from other data, as explained in footnotes to the tables. Expressing phenoliccompounds (e.g., TriBP, OH-BDEs) on a lw basis is problematic if these compounds arenot primarily associated with lipid.
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e115100
6.3. Fish, seabirds and marine mammals
Most reports of bromophenolic HNPs in Arctic/Subarctic andBaltic regions have concerned fish, seabirds and marine mammals.Bromophenolic compounds in these fauna are summarized in threeSupporting Information (Tables S2, S3 and S4) as ranges, means(arithmetic or geometric) or medians of 2,4,6-triBP, 2,4,6-triBA, twoabundant MeO-BDE and OH-BDE congeners (6-MeO-BDE47, 20-MeO-BDE68, 6-OH-BDE47, 20-OH-BDE68)
PMeO-BDEs,
POH-
BDEs andP
PBDDs, andP
PBDEs and BDE-47 when reported in thesame study. Most concentrations are reported on a lw basis if soreported, or converted from a ww basis if percent lipid or EOM isalso specified. Concentrations are listed by ww if no lipid infor-mation is given. Readers are referred to the original papers foridentities and numbers of congeners in summation groups andother bromophenolics occasionally reported but not included in thetables (e.g., 2,4-diBP and 2,4-diBA; BDEs with multiple hydroxy- ormethoxy-groups).
Overviews are presented in box-and-whisker plots of Fig. 6 asconcentrations of class sums in fish, birds and marine mammals.Concentrations are in ng g�1 lw from Tables S2, S3 and S4, andincluded blood, plasma, muscle, egg, liver and whole-body, as re-ported. In cases where concentrations were reported only in wwand no lipid information was given, lipid percentages wereassumed from other data, as explained in footnotes to the tables.Expressing phenolic compounds (e.g., triBP, OH-BDEs) on a lw basisis problematic if these compounds are not primarily associatedwith lipid.
6.3.1. FishScreening of fishmeal samples from worldwide sources have
revealed widespread distribution of PBDEs, MeO-BDEs and OH-BDEs in marine and freshwater [83]. Most of the fish were fromtemperate and tropical regions. The few reports involving speci-mens fromArctic-Subarctic or Baltic regions are summarized belowand in Table S2.
6.3.1.1. Arctic char. Arctic char (Salvelinus alpinus) muscle from theFaroe Islands collected in the 2009 Nordic screening study con-tained <1.7, 12.1 and 1.3 ng g�1 lw 2,4-diBP, 2,4,6-triBP and 2,4,6-triBA [125].
6.3.1.2. Cod and polar cod. The following concentrations of 2,4-diBP, 2,4,6-triBP and 2,4,6-triBA were found in cod liver (Gadusmorhua) from the 2009 Nordic BFRs screening study [125]: FaroeIslands 10, 135 and 21.9 ng g�1 lw. Iceland 0.58, 7.6 and 0.8 ng g�1
lw. Norway 2.4e8.7, 26e70 and ND to 4.3 ng g�1 lw. Cod liver fromVestertana Fjord (70.43 oN, 27.87 oE) collected between 1987 and1998 contained two structurally unidentified tetrabromo-MeO-BDEs with total concentrations 0.32e17.3 ng g�1 lw [171]. Codliver from Trondheim Fjord contained 6.3e6.4 ng g�1 ww 2,4,6-triBA, 0.75 ng g�1 ww 2,6-diBA, 0.71 ww diBP (substitution notspecified), 2.5e3.3 ng g�1 ww (20MeO-BDE68þ 6-MeO-BDE47) and19e22 ng g�1 ww
P6PBDEs [162]. The
P6MeO-BDEs in liver of cod
caught in the Baltic by a commercial company in 2013 averaged5.4 ng g�1 lw [172]. The mean
P12OH-BDEs in these cod liver
samples was 2.8 ng g�1 lw, whileP
36PBDEs was 58 ng g�1 lw. Themedian concentration of
P7 tetra-through octaBDDs in these cod
liver samples was 0.0084 ng g�1 lw, with main congeners 1,2,3,7,8-pentaBDD, 1,2,3,4,7,8-hexaBDD, 1,2,3,7,8,9-hexaBDD and1,2,3,4,6,7,8-heptaBDD. The median concentration of
P5 tetra-
through heptaBDFs was 0.0118 ng g�1 lw, with main congeners2,3,7,8-tetraBDF; 1,2,3,7,8-pentaBDF; 2,3,4,7,8-pentaBDF;1,2,3,4,7,8-hexaBDF and 1,2,3,4,6,7-hepta-BDF.
The geometric mean concentration ofP
10MeO-BDEs in muscle
of polar cod (Boreogadus saida) from Hudson Bay (collected1999e2003) was 9.9 ng g�1 lw, while the
P15PBDEs was 9.8 ng g�1
lw. OH-BDEs were below detection limits of 0.09e0.5 ng g�1 lw)[101].
6.3.1.3. Eel. TheP
15PBDDs in single eel (Anguilla anguilla) musclespecimens, collected from the Baltic Proper in 2000e2001, rangedfrom 0.013e0.075 ng g�1 ww [139].
6.3.1.4. Greenland shark. 2,4,6-TriBA, MeO-BDEs and PBDEs weremeasured in twenty Greenland shark muscle and liver samplescollected in 2001e2003 from Icelandic waters [106]. Median con-centrations of 2,4,6-triBA in muscle and liver were 0.37 and
0.28 ng g�1 lw, respectively. Median concentrations ofP
5MeO-BDEs for muscle and liver were both 100 ng g�1 lw, which washigher than for the
P12PBDEs (35 and 41 ng g�1 lw, respectively).
The predominant congeners were 6-MeO-BDE47 and 20-MeO-BDE68. A significant correlation was found between log-transformed concentrations of 6-MeO-BDE47 and BDE-47 inGreenland shark muscle, but not liver. Concentrations of the twoOH-BDE analogs of these were much lower at <0.01e0.11 ng g�1 lw.
6.3.1.5. Herring. Concentrations of 2,4,6-triBP and 2,4,6-triBA inwhole-body herring (Clupea harengus), collected from the Stock-holm Archipelago (Baltic Proper) in 2013, ranged from 3.9e10 and20e35 ng g�1 lw, respectively [173]. Herring collected in 1993contained 0.38 ng g�1 ww 6-MeO-BDE47 and 0.11 ng g�1 ww 20-MeO-BDE68 [174]. Herring (whole-body) collected fromAsk€o in theBaltic Proper (58.82 oN, 17.62 oE) and €Angsk€arsklubb in the south-ern Bothnian Sea (60.50 oN, 18.08 oE), collected in 2012, contained9.3e420 ng g�1 lw 6-MeO-BDE47, 1.5e73 ng g�1 lw 20-MeO-BDE68and 18e490 ng g�1 lw
P7 MeO-BDEs, while the corresponding
concentrations of 6-OH-BDE47, 20-OH-BDE68 andP
7 OH-BDEswere 3.7e19, 0.17e0.82, and 4.4e21 ng g�1 lw, respectively [173].Concentrations of OH-BDEs in Baltic Proper herring increased be-tween 1980 and 2010, while condition and fat content decreased[173].
6.3.1.6. Perch. Perch muscle from Finland collected in the 2009Nordic screening study contained 2,4-diBP, 2,4,6-triBP and 2,4,6-triBA in the ranges <1.4e34, 8.6e250 and 2.1e15.7 ng g�1 lw,while these concentrations in perch muscle from Sweden were34e7.5, 7.5e68 and NDe2.9 ng g�1 lw. [125]. The
P5MeO-BDEs in
perch muscle collected in the Baltic between 1990 and 2005 aver-aged 34 ng g�1 lw [114]. BAs, BPs, MeO-BDEs and OH-BDEs weredetermined in whole-body perch collected from the StockholmArchipelago in 2013 [161]. Concentration ranges (ng g�1 lw) were2,4-diBP 7.2e74, 2,4,6-triBP 6.3e69, 2,4-diBA 1.9e6.3, 2,4,6-triBA20e48,
P7OH-BDEs 72e391 and
P7MeO-BDEs 23e45.
PBDD concentrations were reported in the Baltic Sea for perch,herring and eel, collected between 2000 and 2004 [139]. Levels ofP
15 tri-, tetra- and pentaBDDs in all fish ranged from belowdetection to 0.075 ng g�1 ww, and were below detection in severalfreshwater lakes close to the coast. In perch muscle compositesfrom marine areas, the
P10PBDDs was 0.002 ng g�1 ww in the
Baltic Proper, and ranged from NDe0.00011 ng g�1 ww (detectionlimit not specified) in the northern Baltic (Bothnian Bay andBothnian Sea). As in mussels (Section 6.2) and macroalgae (Section6.1), the
P10PBDDs consisted almost entirely of di- and triBDDs,
with much lower levels of tetraBDDs. A further investigation ofperch collected from the Baltic Proper between 1990 and 2005showed an average
P15PBDD concentration of 0.48 ng g�1 lw and
no apparent trend over the time period except for an unexplainedspike in 1995 [114]. TriBDDs and tetraBDDs accounted for 75e80%and 5e10%, respectively, of
P15PBDDs in samples with high con-
centrations, whereas the contribution of tetraBDDs increased to30e40% in low-level samples.
6.3.1.7. Saithe. Saithe (Pollachius virens) liver from Sklinna, Norwaycontained 54.7 ng g�1 ww 2,4,6-triBA, 1.7 ng g�1 ww 2,6-diBA,1.4 ng g�1 ww (20-MeO-BDE68 þ 6-MeO-BDE47) and 14 ng g�1 wwP
6PBDEs [162].
6.3.1.8. Salmon. Whole-body homogenates of pooled Atlanticsalmon (Salmo salar) collected from Hraunsfj€ordur, Iceland (64.96oN, 23.00 oW) in 1998 contained
P2 tetra-MeO-BDEs
1.8e4.0 ng g�1 lw andP
7PBDEs 12 ng g�1 lw [171]. TheP
tri-MeO-BDEs (number unspecified) was also quantified at
14e30 ng g�1 lw. The geometric mean concentrations ofP
10MeO-BDEs and
P15PBDEs in muscle of salmon from Hudson Bay, Canada
(collected 1999e2003) were 42 and 9.3 ng g�1 lw, while OH-BDEswere below detection (<0.02 to <0.09 ng g�1 lw) [101]. Salmoncollected in 2004 from aquaculture operations in Norway contained2,4,6-triBA in the range 5e39 ng g�1 lw, while the concentrationwas 17 ng g�1 lw in one specimen from an aquaculture farm in theFaroe Islands [175]. In the Baltic, OH-BDEs, MeO-BDEs and similarcompounds with both bromine and chlorine substitution wereidentified in salmon collected in 1995, but levels were not quanti-fied [113,114,176]. Salmon muscle, sampled in 1991, contained40 ng g�1 lw
P4MeO-BDE (structures not identified) while the
P7PBDE concentrations was 300 ng g�1 lw [176].PBDD/Fs were determined in salmon from rivers in Latvia dur-
ing 2012 [178]. The fish were collected during the spawning seasonand thus represented the open Baltic. PBDFs dominated thebrominated compounds profile, with main contributions from2,3,7,8-tetraBDF, 1,2,3,4,6,7,8-heptaBDF, and octaBDF Congeners1,2,3,4,7,8-hexaBDD and 1,2,3,4,6,7,8-heptaBDF were found in allsamples, while 2,3,7,8-tetraBDD and 1,2,3,4,7,8e/1,2,3,6,7,8-hexaBDD were detected in four samples. The
P13PBDD/Fs aver-
aged 0.041 ng g�1 lw, estimated from reported concentrations on aww basis and average lipid content of 5.7%. PCDD/Fs and mixedbromo-chloro- congeners were also identified. TEQ contributed byPBDD/Fs were only 2.1% of total TEQ from PBDD/F þ PCDD/F con-geners. Di- and triBDDs, common in other Baltic fish (Section6.3.1.6), were apparently not sought. The
P27PBDEs in these sam-
ples ranged from 24e98 ng g�1 lw.
6.3.1.9. Sculpin. The geometric mean concentration ofP
10MeO-BDEs inmuscle of sculpin (Myoxocephalus scorpioides) fromHudsonBay (collected 1999e2003) was 3.0 ng g�1 lw, while the
P15PBDEs
was 15 ng g�1 lw. OH-BDEs were below detection [101].
6.3.1.10. Stickleback. Concentrations of 2,4-diBP, 2,4,6-triBP and2,4,6-triBA in whole three-spined stickleback (Gasterosteus acu-leatus), collected from the Stockholm Archipelago in 2013, rangedfrom 41e178, 174e1170 and 58e86 ng g�1 lw, while ranges forP
7OH-BDEs andP
7MeO-BDEs were 141e426 and 29e191 ng g�1
lw [161].
6.3.1.11. Antarctic fish species. Nototheniid fish (Notothenia rossiiand Trematomus newnesi) were collected at Potter Cove, KingGeorge Island/Isla 25 de Mayo, South Shetland Islands (62.23 �S;58.66 �W) in 2008e2011 [179] and analyzed for MeO-BDEs. Meanconcentrations (ng g�1 lw) of 6-MeO-BDE47 in Notothenia rossiiwere: muscle 1.13, liver 3.77, gonads 0.78, gills 1.07, while 20-MeO-BDE68 was below the quantitation limit. Similarly for 6-MeO-BDE47 in Trematomus newnesi (ng g�1 lw): muscle 3.08, liver 2.47,gonads 2.55 and gills 3.10. 20-MeO-BDE68 was found in some ofthese tissues: muscle 0.07, liver 0.09 and 0.07, but below thequantitation limit in gonads. Significant positive associations(p< 0.05) were found between the concentration of 6-MeO-BDE47in gill and total length and weight in N. rossii and negative associ-ation between 6-MeO-BDE47 concentration body condition indexin T. newnesi. Similar relationships were also found for PBDEs,organochlorine pesticides and PCBs.
6.3.2. Seabirds6.3.2.1. Black-legged kittiwake. Concentrations of 2,4,6-triBA inplasma of black-legged kittiwake (Rissa tridactyla) chicks capturedon Svalbard in 2006 ranged from 0.02e0.07 ng g�1 ww [180].
6.3.2.2. Eider. Eggs of common eider (Somateria mollisima) werecollected in 2012 from the Norwegian coastal sites of Sklinna and
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e115102
Røst [181]. The 2,4,6-triBP and 2,4,6-triBA concentrations in eggpools from Sklinna were 0.29e21 and 0.55e1.1 ng g�1 ww, andwere 0.29e0.67 and 0.25e0.61 ng g�1 ww at Røst. 2,4-DiBP wasalso found, <0.05e1.4 ng g�1 ww at Sklinna and <0.05e2.9 ng g�1
ww at Røst. One egg pool from Sklinna contained 0.38 ng g�1 wwpentaBP, and <0.2 ng g�1 ww in other egg pools from the two lo-cations. The
P16 PBDE concentrations in eggs from Sklinna and
Røst were 0.22e0.28 and 0.30e0.79 ng g�1 ww, respectively. Thegeometric mean concentrations of
P10MeO-BDE and
P15PBDEs in
livers of common eider collected between 1999 and 2003 in Hud-son Bay (Canada) were 1.3 and 20 ng g�1 lw, while OH-BDEs werebelow detection [101].
6.3.2.3. Glaucous gull. Bromophenolic HNPs and PBDEs weremeasured in blood, plasma, liver, egg yolk and whole body (withand without feathers) of glaucous gull collected in the NorwegianArctic in the Svalbard Archipelago) (79�N, 19�E) and Bjørnøya(74.37 �N, 19.08 �E) between 2002 and 2006 [107,182e184]. Meanconcentrations of
P7MeO-BDEs,
P7OH-BDEs and
P12PBDEs in
plasma of gulls in 2004 were 0.82, 0.40 and 20 ng g�1 ww,respectively (average of males and females) [107,182]. Prominentcongeners were 3-MeO-BDE47 (or 20- MeO-BDE66), 6-MeO-BDE47,40-MeO-BDE49 and their OH- analogs. Subsequent sampling ofBjørnøya gulls in 2006 showed
P15MeO-BDEs,
P14OH-BDEs and
P38PBDEs concentrations in plasma (male, female average) 1.51,
2.46 andP
38PBDEs 13.7 ng g�1 ww, respectively, while 20.2 ng g�1
wwP
15MeO-BDEs and 163 ng g�1 wwP
38PBDEs were found inegg yolk [184].
Equal numbers of Svalbard gulls were captured at a Ny Ålesundrefuse dump in 2002, fed a diet of juvenile Arctic cod, and sacrificedfor analysis after three days of basal metabolism measurements[182]. MeO-BDEs and OH-BDEs were determined in blood, liver andwhole-body homogenates with and without feathers. Mean con-centrations (ng g�1 ww) of
P6MeO-BDEs in these compartments
were 2.78, 32.2, 9.23 and 19.4, respectively, whileP
7OH-BDEswere 3.54, 3.57, 0.87 and 0.27. The mean concentrations ofP
12PBDEs were 51.5, 522, 178 and 202 ng g�1 ww.
6.3.2.4. Guillemot and black guillemot. Eggs of guillemot (Uriaaalge) were collected between 2002 and 2005 from Vestman-naeyjar, Iceland (63.4 oN, 20.3 oW), Sandøy, Faroe Islands (61.8 oN,6.8 oW), and Hjelmsøya (71.1 oN, 24.7 oE), Bjørnøya (74.4 oN,19.0 oE)and Sklinna (65.2 oN, 11.0 oE) Norway), with comparative samplingat Stora Karls€o (57.3 oN, 18.0 oE) in the Baltic Proper, Sweden [185].The range of geometric mean concentrations of BDE-47 in Arctic/Subarctic birds was 5.9e38 ng g�1 lw. MeO-BDEs were onlydetected at the Baltic site: geometric means of 9.8 ng g�1 lw 20-MeO-BDE68, 5.1 ng g�1 lw 6-MeO-BDE47 and 2.9 ng g�1 lw 6-MeO-BDE90, and the Baltic guillemots had a geometric mean BDE-47concentration of 120 ng g�1 lw. Concentration ranges of 6-OH-BDE47 and 20-OH-BDE68 in Arctic/Subarctic birds were 0.44e17and NDe0.53 ng g�1 lw, respectively. Pooled guillemot eggs fromStora Karls€o, collected in the 2009 Nordic BFR screening study,contained the following concentrations 1.7 ng g�1 lw 2,4-diBP,1.7 ng g�1 lw 2,4,6-triBP and 0.14 ng g�1 lw 2,4,6-triBA [125].
A whole-body homogenate of guillemot from the Baltic Proper,collected in 1998, contained 2.0 ng g�1 lw of
P3tetrabromo MeO-
BDEs with unidentified structures, but no MeO-BDEs were foundin guillemot from the Norwegian west coast [171]. The
P7PBDEs in
the Baltic versus Norwegian coastal guillemot were 231e332 and76e118 ng g�1 lw, respectively.
Concentration ranges in eggs of black guillemot (Cepphus grille)from the Faroe Islands, collected during the 2009 Nordic BFRscreening study, were 0.75e0.93 ng g�1 lw 2,4-diBP, 8.8e19 ng g�1
lw 2,4,6-triBP and 0.20e0.24 ng g�1 lw 2,4,6-triBA [125].
6.3.2.5. Herring gull. Herring gull (Larus argentatus) egg samplesfrom Sklinna and Røst collected in 2012 contained 2,4,6-triBAconcentrations of 0.11e0.13 and 0.10e0.57 ng g�1 ww, respec-tively, 2,4,6-triBP concentrations of 0.12e0.17 and 0.26e0.34 ng g�1
ww, respectively andP
PBDE concentrations of 9.8e12.7 and10.3e16.8 ng g�1 ww, respectively [181].
6.3.2.6. Long-tailed duck. Long-tailed duck (Clangula hyemalis)which breeds in freshwaters of Siberia and northern Europe werecollected in the Baltic Proper between 2000 and 2009 and theirlivers were analyzed for BPs, BAs, OH-BDEs and MeO-BDEs [160].Geometric concentrations were 0.57 ng g�1 lw for 2,4-diBP þ 2,4,6-triBP, and 0.83 ng g�1 lw for 2,4-diBA þ 2,4,6-triBA. The geometricmean concentrations of
P7MeO-BDEs,
P7OH-BDEs and
P7PBDEs
were 3.8, 6.1 and 8.0 ng g�1 lw, respectively. 6-MeO-BDE47 and 6-OH-BDE47 dominated the classes, while the abundance of MeO-BDE congeners was 6-MeO-BDE47 > 6-MeO-BDE99 > 6-MeO-BDE90> 20-MeO-BDE68.
6.3.2.7. Northern fulmar. The triBA (isomer unspecified) concen-trations in liver of northern fulmar from Bjørnøya ranged from0.4e0.8 ng g�1 lw [186]. Plasma levels were measured in fulmarscollected from Svalbard in 2006, and only one out of eight waspositive, at 0.09 ng g�1 ww [176].
6.3.2.8. Shag. Two studies have examined bromophenolic HNPs inegg and liver samples from European shag (Phalacrocorax aristote-lis) from coastal Norway, at Sklinna [161,177] and Røst [177]. The2,4,6-triBA concentrations in shag egg samples collected in 2012were 0.45e1.02 ng g�1 ww (Sklinna) and 1.45e1.91 ng g�1 ww(Røst); 2.4.6-triBP 0.19e0.24 ng g�1 ww (Sklinna), 0.14e0.72 ng g�1
ww (Røst) [181]. In comparison, 2,4,6-triBA concentrations in eggand liver samples from Sklinna collected in 2003 were 0.35e11.4and 0.61e3.3 ng g�1 ww, respectively [162]. Concentrations of 20-MeO-BDE28 and 6-MeO-BDE47 in the 2003 Sklinna eggs were0.023e0.09 and 0.059e0.36 ng g�1 ww, while liver samples con-tained only 20-MeO-BDE68 at 0.18e12.8 ng g�1 ww. The
P16PBDE
concentrations in the 2012 egg samples were 2.0e3.9 ng g�1 ww(Sklinna) and 2.5e3.9 (Røst) [181], while
P7PBDE concentrations
in Sklinna egg and liver samples collected in 2003were 0.8e4.9 and0.13e0.43 ng g�1 ww, respectively [162].
6.3.2.9. White-tailed sea eagle. White-tailed sea eagles fromGreenland were sampled in 2007e2009 [108]. Median 20-MeO-BDE68 þ 6-MeO-BDE47 concentrations were 41, 16, 29, 26, 22, and8.8 ng g�1 lw in muscle, preen oil, liver, kidney, blood and adiposetissue, respectively, and consisted of 56e75% 6-MeO-BDE47. Me-dian
P7PBDE concentrations in these tissues were 420, 190, 180,
150, 150 and 150 ng g�1 lw, respectively. Significant correlationswere found between individual BDE congeners and the MeO-BDEs,which suggests similar bioaccumulation pathways.
MeO-BDEs and PBDEs were measured in eggs of white-tailedsea eagle from Arctic inland (collected 1994e2005) and southerninland (1992e2005) areas of Sweden, and from the northern Baltic(Bothnian Sea, 1992e2004) and Baltic Proper (1994e2001) [187].Mean concentrations (ng g�1 lw) of
collections on the southern Baltic coast were compared with anarchived egg laid in 1941, also on the southern Baltic Sea coast [82].Concentrations of 20-MeO-BDE68 and 6-MeO-BDE47 were virtuallythe same in the 1996e2001 eggs (geometric means 23 and90 ng g�1 lw) and the single 1941 egg (30 and 86 ng g�1 lw). Bycontrast, the geometric mean of
P5PBDEs in the recent egg was
3120 ng g�1 lw, while each PBDE congener was <2 ng g�1 lw in the1941 egg. These findings provide support for a natural origin of thetwo MeO-BDE congeners.
6.3.2.10. White-winged scoter. Geometric mean concentrations ofP
10MeO-BDEs andP
15PBDEs in liver of white-winged scoter(Melanitta fusca) from eastern Hudson Bay, Canada were 1.3 and71 ng g�1 lw; OH-BDEs were not detected [101].
6.3.2.11. Antarctic bird species. Plasma and eggs of the rockhopperpenguin (Eudyptes chrysocome chrysocome) were collected at anesting site on New Island, Malvinas/Falkland Islands (51.43 oS,61.17 oW) in 2008e2009 [188]. Only 6-MeO-BDE47 was found infemale plasma at 0.10e0.17 ngmL�1, while both 6-MeO-BDE47(6.9e7.1 ng g�1 lw) and 20-MeO-BDE68 (0.55e0.56 ng g�1 lw) werepresent in egg yolk. The
P4PBDEs ranged from 0.05e0.11 ngmL�1
in plasma and 0.40e0.44 ng g�1 lw in egg yolk. A separate study ofeggs collected in 2008 showed mean concentrations in the yolk of7.01 ng g�1 lw 6-MeO-BDE47, 0.55 ng g�1 lw 20-MeO-BDE68 and0.98 ng g�1 lw
P7PBDEs [185].
Egg yolk of imperial shag (Phalacrocorax atriceps) from theFalkland Islands (see above) contained 0.50 ng g�1 lw 6-MeO-BDE47, 0.17 ng g�1 lw 20-MeO-BDE68 and 1.92 ng g�1 lw
P7PBDEs
[189].
6.3.3. Marine mammalsMeO-BDEs have been reported in odontocete and mysticete
cetaceans from temperate and tropical waters, and less frequentlyin the Arctic Ocean and regional seas, the Baltic Sea and SouthernOcean [190].
Rotander et al. [109,191] surveyed MeO-BDEs and PBDEs inpooled blubber samples of several marine mammal species: pilotwhale (Globicephala melas), ringed seal (Pusa hispida), minke whale(Balaenoptera acutorostrata), fin whale (B. physalus), harbor por-poise (Phocoena phocoena), hooded seal (Cystophora cristata), andAtlantic white-sided dolphin (Lagenorhynchus acutus), collectedfrom Arctic and Subarctic locations off the Faroe Islands, Norway,Greenland and Iceland, over a period of more than 20 years(1986e2009). These are the only data for MeO-BDEs in many spe-cies in the region. The overall concentration ranges for all marinemammal species examined by Rotander et al. [109] were0.2e23 ng g�1 lw (20-MeO-BDE68), 0.3e653 ng g�1 lw (6-MeO-BDE47), 2.4e1389 ng g�1 lw (BDE47) and 18e2792 ng g�1 lw(P
10PBDEs). BDE47 andP
2MeO-BDEs (20-MeO-BDE68 and 6-MeO-BDE47) in these animals are shown in Fig. 7. Highest MeO-BDE levels were found in the toothed whales (pilot whale andwhite-sided dolphin), and these sometimes exceeded concentra-tions of BDE47. Levels were lower in the baleen whale species(minke whale and finwhale), and lowest in hooded seal and ringedseal. Strong correlations were found between the log-transformedconcentrations of 20-MeO-BDE68 and 6-MeO-BDE47 in seven ma-rine mammal species from the North Atlantic and westernGreenland. Data for all Arctic-Subarctic and Baltic marinemammalsare summarized in Table S4 and by species below.
lw) in blubber of Atlantic white-sided dolphin from the FaroeIslands, sampled in 1997, 2001e2002 and 2006, were: 6-MeO-BDE47 5.6e438, 20-MeO-BDE68 1.6e14, and
P10PBDEs 333e1021
[109,191].
6.3.3.2. Beluga whale. Kelly et al. [101] reported MeO-BDEs, OH-BDEs and PBDEs in 5e14 (depending on the compound deter-mined) in beluga whale (Delphinapterus leucas) from easternHudson Bay, Canadian Arctic, sampled between 1999 and 2003.Geometric mean concentrations of
P10MeO-BDEs in blubber were
310, 62 and 300 ng g�1 lw in calves, adult females and adult males,respectively. Dominant congeners were 6-MeO-BDE47> 20-MeO-BDE68 > 60-MeO-BDE49. Others found at lower levels were 60-MeOBDE17, 20-MeO-BDE28, 4-MeO-BDE42, 5-MeO-BDE47, 60-MeO-BDE66, 6-MeO-BDE90 and 6-MeO-BDE99. These compounds werealso reported inwhole blood (female, male), milk (female) and liver(male) (Table S4). Levels of
P5OH-BDEs in blubber were much
lower: 0.23 ng g�1 lw in calves, below detection in adult femalesand 0.1 ng g�1 lw in adult males, while corresponding levels ofP
16PBDEs were 27, 16 and 34 ng g�1 lw.Liver samples from two beluga, collected inwestern Hudson Bay
2002e2003, contained 20-MeO-BDE68 and 6-MeO-BDE47, whereastwo beluga liver samples collected from the St. Lawrence estuary insouthern Canada (2000e2003) contained 40-MeO-BDE17 and 6-MeO-BDE47 [192]. The summed concentrations of these two con-geners were 43e100 ng g�1 lw in Hudson Bay and 20e25 ng g�1 lwin the St. Lawrence estuary.
6.3.3.3. Fin whale. Concentration ranges (ng g�1 lw) in blubber offin whale from west Iceland, sampled between 1986e1987 and2006e2009, were: 6-MeO-BDE47 11e55, 20-MeO-BDE68 1.4e8.1and
P10PBDEs 18 to 82 [109,191].
6.3.3.4. Harbor porpoise. Concentration ranges (ng g�1 lw) inblubber of harbor porpoise from Norway, sampled in 1992, 1997,and 2000 were: 6-MeO-BDE47 36e110, 20-MeO-BDE68 3.2e4.9 andP
10PBDEs 106e605 [109,191].
6.3.3.5. Hooded seal. Concentration ranges (ng g�1 lw) in blubberof hooded seal fromwest Iceland, sampled in 1990, 1997 and 2007,were: 6-MeO-BDE47 6.4e14, 20-MeO-BDE68 1.2e2.3 andP
10PBDEs 46e161 [109,191].
6.3.3.6. Minke whale. Concentration ranges (ng g�1 lw) in blubberof minke whale from Norway or Greenland, sampled in 1993, 1996,1998, 2003 and 2006, were: 6-MeO-BDE47 1.9e86, 20-MeO-BDE680.9e13 and
P10PBDEs 86e412 [109,191].
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e115104
6.3.3.7. Pilot whale. Concentration ranges (ng g�1 lw) in blubber ofpilot whale from the Faroe Islands, sampled in 1986, 1997 and2006e2007, were: 6-MeO-BDE47 90e653, 20-MeO-BDE68 4.3e23and
P10PBDEs 479e2792 [109,191]. Out of 14 OH-BDEs sought in
pilot whale plasma (sampled 2010e2011), only 40-OH-BDE17 wasfound in 10 animals at 1.0e5.7 ng g�1 ww, and 60-OH-BDE49 wasfound in one whale at 0.8 ng g�1 ww [193]. PBDD/Fs were deter-mined in blubber of juvenile male pilot whales sampled in theFaroe Islands between 1997e2013 [194]. Furans dominated theclass, accounting for 79% of
P11PBDD/Fs which were monitored,
with total concentrations ranging from 0.080e71 pg g�1 lw.1,2,3,4,6,7,8-heptaBDF was the most abundant PBDF, followed by2,3,7,8-tetraBDF. Among the PBDDs, which were detected in onlyseven out of 26 specimens, the most abundant congeners were1,2,3,4,6,7,8-heptaBDD and 1,2,3,4,7,8-/1,2,3,6,7,8-hexaBDD, and2,3,7,8-tetraBDD was found in one specimen. Di- and triBDDs,common in Baltic fish (Section 6.3.1.6) were apparently not sought.The
P9PBDEs in these samples ranged from 140e1900 ng g�1 lw.
No relationship was found betweenP
11PBDD/Fs andP
9PBDEs.
6.3.3.8. Polar bear. Only two OH-BDE congeners were detectedamong the 14 congeners monitored in polar bear (Ursus maritimus)from east Greenland (collected 1999e2001) [195]. There weretissue-specific differences. 6-OH-BDE-47 was found only in adiposetissue, while 3-OH-BDE-47 was found mainly in blood but also inadipose tissue. These tissues were also screened for 15 MeO-BDEcongeners (40-MeO-BDE17, 60-MeO-BDE17, 20-MeO-BDE28, 4-MeO-BDE42, 3-MeO-BDE47, 5-MeOBDE47, 6-MeO-BDE47, 40-MeO-BDE49, 60-MeO-BDE49, 20-MeO-BDE68, 6-MeO-BDE85, 6-MeO-BDE90, 6-MeOBDE99, 2-MeO-BDE123, 6-MeO-BDE137).Only three MeO-BDEs were detected in the adipose tissue andblood and none in liver or brain. The mean concentrations ofP
14OH-BDE were 0.9 ng g�1 ww (adipose tissue) and 2.9 ng g�1
ww (blood), while levels ofP
15MeO-BDE were <0.1e25 ng g�1 ww(adipose tissue) and <0.19e0.78 ng g�1 ww (blood). Concentrationsof
P13PBDEs averaged 83 ng g�1 ww (adipose tissue), 1.2 ng g�1
ww (blood), 2.9 ng g�1 ww (brain), and 40 ng g�1 ww (liver).In a study of female polar bears sampled in Svalbard (2002),
concentration ranges in plasma were <0.01e0.17 ng g�1 ww(P
7MeO-BDEs) and <0.08e0.54 ng g�1 ww (P
6OH-BDEs), whilethe range of
P12PBDEs was 2.65e9.72 ng g�1 ww [107].
TheP
10OH-BDEs,P
12MeO-BDEs andP
21PBDEs in liver of polarbear, collected in Alaska, between 1993 and 2002, averaged 0.012,0.026 and 0.74 ng g�1 ww, respectively [99]. Major congeners were20-MeO-BDE68, 6-MeO-BDE47, 50-MeO-BDE100, 20-OH-BDE68,60OH-BDE47 and 40-OH-BDE49. Sixteen BPs were also monitored.The main congeners found were 2,4-diBP, 2,4,6-triBP and 2,4,5-triBP was also detected. The
P16BPs averaged 0.16 ng g�1 ww.
Strong correlations were found between log-transformed concen-trations of 6-OH-BDE47 and 6-MeO-BDE47 (p< 0.001), betweenP
10OH-BDEs andP
12MeO-BDEs (p< 0.001), and betweenP
10OH-BDEs þ P
16BPs andP
12MeO-BDEs (p< 0.001).
6.3.3.9. Ringed seal. The concentration ranges (ng g�1 lw) inblubber of ringed seal from east Greenland, sampled in 1986, 2000and 2006, were: 6-MeO-BDE47 0.3e2.8, 20-MeO-BDE68 0.2e0.9and
P10PBDEs 23e72 [109,191].
The geometric mean concentration ofP
10MeO-BDEs in blubberof male ringed seal, collected from Hudson Bay between1999e2003, was 6.7 ng g�1 lw and consisted almost entirely of 6-MeO-BDE47 (67%) and 20-MeO-BDE68 (27%). The geometric meanconcentration of
P15PBDEs was 11 ng g�1 lw. OH-BDE congeners
were below 0.007 ng g�1 lw [101].OH-BDEs and PBDEs were reported in plasma of ringed seals
collected from Svalbard (2007) and the Baltic Sea (2002, 2006 and
2007) [196]. For the Svalbard animals, the mean concentrations ofP
5OH-BDEs andP
10PBDEs were 0.019 ng g�1 ww (consisting ofonly 3-OH-BDE47 and 6-OH-BDE47) and 1.1 ng g�1 ww, respec-tively. Levels were higher in Baltic seals, averaging 0.36 ng g�1 wwP
5OH-BDEs and 7.1 ng g�1 wwP
10PBDEs. A greater variety of OH-BDEs was found in Baltic seals, consisting of 20-OH-BDE68, 6-OH-BDE67, 3-OH-BDE47, 6-OH-BDE90 all at 0.066e0.079 ng g�1 wwand 40-OH-BDE49 at 0.026 ng g�1 ww.
Out of 15 MeO-BDEs and 14 OH-BDEs sought in ringed sealblubber from east Greenland in 2001e2002, only 6-MeO-BDE47, 20-MeO-BDE68, 6-MeO-BDE85, and 6-OH-BDE47 were found [197].Concentrations averaged 4.6 ng g�1 lw (
P3MeO-BDEs) and
0.7 ng g�1 lw (6-OH-BDE47), while the concentration ofP
13PBDEswas 149 ng g�1 lw. Biomagnification factors from ringed seal topolar bear (adipose tissue) were low: 1.0 (
P3MeO-BDEs), 1.3 (6-
OH-BDE47), and 0.64 (P
13PBDEs). The MeO-BDEs and OH-BDEswere likely natural, as ringed seal appears to have a low capacityfor oxidative metabolism of PBDEs.
PBDD/Fs were determined in blubber of Baltic ringed seal (Pusahispida botnica) collected between 1974e2015 [198]. The
P11PBDD/
Fs ranged from 0.0005e0.052 ng g�1 lw, with main contribution by1,2,3,4,6,7,8-heptaBDD (61%), followed by 1,2,3,4,6,7,8-heptaBDD(13%). Lower concentrations but more frequently detected conge-ners were 2,3,7,8-tetraBDF and 2,3,7,8-tetraBDD. Di- and triBDDswere not sought. The range of
P9PBDEs was 18.7e503 ng g�1 lw.
6.3.3.10. Other mammalian species. Although not marine mam-mals, these animals are included because they live in the Arctic andconsume marine prey. OH-BDEs were determined in liver of Arcticfox (Vulpes lagopus), collected from Svalbard over seven years from1997e2011 [199]. Only two congeners were found out of fivemonitored: 6-OH-BDE47 was identified in 24% of 100 samples at amean concentration of 0.38 ng g�1 ww, while 40-OH-BDE49occurred in only one sample at 0.71 ng g�1 ww. 6-MeO-BDE47appeared related to marine diet, although the relative contributionof natural sources versus metabolism of PBDEs was unclear.
Dietary accumulation of POPs in female sledge dogs (Canisfamiliaris) was tested in the community of Disco Bay, Greenland(69.00 oN, 52.00 oW) by feeding eight dogs with minke whaleblubber, while a control set of eight dogs ate pork fat [200]. Accu-mulation of PBDEs, PCBs and chlorinated pesticides was higher inthe whale-fed dogs, and so were metabolites OH-BDEs and OH-PCBs. The average
P14OH-BDEs was 1.2 ng g�1 ww in whale-fed
dogs and 0.2 ng g�1 ww in the pork-fed dogs.
6.3.4. Freshwater environment2,4-DiBA and 2,4,6-triBA were measured in larvae of black fly
(Simuiidae sp.) and water (Section 5) collected in tundra streamsnear Abisko, Sweden [151]. Concentrations of 2,4-diBA and 2,4,6-triBA ranged from 4.2e42 ng g�1 dw and 2.9e7.4 ng g�1 dw,respectively. Pike (Esox lucius) from Subarctic Lake Storvindeln(56.84 oN, 13.67 oE, collected 1993) in the north and lakes Bolmen(65.72 oN, 17.06 oE, collected 1967e2000) and Roxen (58.51 oN,15.64 oE, collected 1972) in southern Sweden were analyzed forPBDEs and MeO-BDEs [174]. The two biogenic congeners 20-MeO-BDE68 and 6-MeO-BDE47 were found in all years. Highest con-centrations of 6-MeO-BDE47 and 20-MeO-BDE68 were found inmuscle of pike from Lake Bolmen (290e3600 and 110e1800 pg g�1
ww)> Lake Storvindeln (35 and 110 pg g�1 ww)> Lake Roxen (1.9and 1.4 pg g�1 ww). MeO-BDE levels in pikewere equal to or greaterthan PBDE concentrations, but did not correlate with PBDEs nor didthey show relationships with eutrophication, location or samplingseason. A follow up study was done in 2008, in which MeO-BDEswere detected in Arctic char, pike and perch in 10 out of 32Swedish inland lakes [201].
Fig. 8. PDBP congener profiles (as percentages of S4PDBPs) in marine mammals fromwaters influenced by Pacific versus Atlantic Ocean transport. Redrawn from Tittlemieret al. [24]. Numbers in parentheses refer to locations specified in that paper.
Concentrations of 20-MeO-BDE68 and 6-MeO-BDE47 in Arcticchar collected from the Arctic lake Abiskojaure in 2005 were 15 and4 ng g�1 lw [187]. Geometric mean concentrations of
P3MeO-BDEs
(20-MeOBDE68 þ 6-MeO-BDE47 þ 5-Cl-6-MeO-BDE47) in eggs ofwhite-tailed sea eagle from freshwater lakes in Arctic Sweden(collected 1994e2005) were 86 ng g�1 lw, and 39 ng g�1 lw incentral and southern inland habitats (collected 1992e2005). Geo-metric mean
P5PBDE concentrations in these birds were 720 and
1500 ng g�1 lw, respectively [187].Several studies have found MeO-BDEs, OH-BDEs and other
bromophenolic compounds in fish [88,201e204] and birds[105,205e207] of temperate inland ecosystems.
7. Other HNPs in marine biota
Compared to bromophenolic compounds, there have been fewreports of other high molecular weight HNPs in the Arctic envi-ronment. These are discussed alongwithmore numerous reports intemperate and tropical ecosystems to guide research into the typesof compounds which could be sought in future Arctic investigations(Fig. 1). Other HNP classes reported in biota include 2,20-dime-thoxy-3,30,5,50-tetrabromobiphenyl (2,20-diMeO-BB80), poly-halogenated 10-methyl-1,20-bipyrroles (PMBPs), polyhalogenated1,10-dimethyl-2,20-bipyrroles (PDBPs), polyhalogenated N-methyl-pyrroles (PMPs), polyhalogenated N-methylindoles (PMIs), bro-moheptyl- and bromooctyl pyrroles (BHPs, BOPs), 1R,2S,4R,5R,1E)-2-bromo-1-bromomethyl-1,4-dichloro-5-(2-chloroethenyl)-5-methylcyclohexane (mixed halogenated compound MHC-1), poly-brominated hexahydroxanthene derivatives (PBHDs), poly-halogenated carbazoles (PHCs), bromovinylphenols (BVPs) andbromocoumarates (BCUs)[9e11,22e25,29e32,48e54,69e77,162,208e214].
2,20-DiMeO-BB80, was first identified in marine mammal sam-ples from the Japanese market, and an analytical standard wassynthesized [213]. The origin is suspected to be marinemicrofauna/flora and bacteria. It is unlikely to arise from transformation ofBB80, since this congener is not present in PBB commercial mix-tures [213]. 2,20-DiMeO-BB80 was subsequently found in dolphinblubber from California [31] and Brazil [29], macroalgae from thePhilippines [42], seawater from the Great Barrier Reef [133,134]blue mussels from the North and Baltic seas [22] and Greenlandshark [106].
PDBPs are a structurally diverse group of compoundscomprising many potential congeners. Early studies were able toconfirm the presence of several PDBP congeners in Arctic fauna aswell as to describe their bioaccumulation in the Arctic food web ofthe Northwater Polynya in 1988 (Section 9) [25]. A comparativestudy was made of PDBPs in blubber of marine mammals from theeastern and western Arctic with those worldwide [24]. The rangesin geometric mean for
PPDBPs in Arctic species were
0.4e1.2 ng g�1 lw (ringed seal), 0.6 ng g�1 lw (bowhead whale,Balaena mysticetus), 2.0e17.8 ng g�1 lw (beluga), 4.3e8.3 ng g�1 lw(harbor seal) and 234 ng g�1 lw (Steller sea lion, Eumetopias juba-tus) from Alaska. Similar concentrations were found in Steller sealion from Japan and California (331 and 177 ng g�1 lw, respectively).However, higher geometric mean concentrations (range:14.3e2540 ng g�1 lw) were generally found in other marinemammals (pinnipeds, cetaceans) from temperate and tropical lat-itudes [24]. Higher concentrations of PDBPs and different patternsof congeners were observed in samples from Pacific Ocean influ-enced environments relative to non-Pacific Ocean influenced en-vironments. DBP-Br4Cl2 dominated the congener profile in Pacificseals (excluding ringed seals), whereas DPB-BrCl3 and DBP-Br5Clwere more prominent in seals from coastal Europe and Svalbard(Fig. 8). Congener patterns also differed in beluga from different
Arctic regions, with DBP-Br4Cl2 predominating in Alaskan animalsand DBP-Br6 in beluga from the Canadian Arctic Archipelago,Svalbard and the St. Lawrence River. It was suggested that PDBPsundergo extensive transport from sources located primarily in thePacific Ocean. Evidence from congener patterns indicates that bothocean currents and atmospheric transport are likely to play a role inthe movement of PDBPs. The occurrence of
PPDBPs at 0.35 ng g�1
lw in the Baikal seal (Pusa sibirica) also suggests air transport [24].Several PDBP congeners were detected in blubber from juvenilemale northern fur seals (Callorhinus ursinus) collected from St. PaulIsland, Alaska (N. Eisenhardt, pers. comm.). The congeners detectedincluded DBP-Br2Cl4, DBP-Br3Cl3 (two congeners), DBP-Br5Cl andDBP-Br6. Confirming the observation made previously, DBP-Br2Cl4was the most abundant of the PDBPs found in the northern fur sealsamples.
PDBPs were determined in humpback dolphin (Sousa chinensis),venus tuskfish (Choerodon venustus) and sea cucumber (Holothuriasp.) from The Great Barrier Reef, Australia, as well as in a strandedsperm whale (Physeter macrocephalus) from the North Sea, and abeluga (Delphinapterus leucas) from Canada [70]. The number ofpossible bromo- þ chloro-PDBP congeners is 36, of which 23 wereidentified in humpback dolphin and 18 in sea cucumber. Concen-trations of
PPDBPs in these species averaged 1119 and 482 ng g�1
lw, respectively. DiMeOH-BB isomers were also identified.Between 9 and 20 PDBP congeners were identified by GCxGC-
ToF nontarget screening in blubber of dolphin species from Cape
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e115106
Cod [30], California [31] and Brazil [29]. Concentrations (ng g�1 lw)of major DBP congeners in Atlantic common dolphin (Delphinusdelphis) blubber were DBP-Br4Cls [124], DBP-Br6.(30.9) and DBP-Br5Cl (16.5) [30].
TheP
6PDBPs in blue mussels from the southern Baltic Sea(Danish Straits) was <0.1 ng g�1 lw, while generally higher con-centrations were found in mussels from the North Sea(<0.1e142 ng g�1 lw) [22]. Prominent congeners were DBP-Br6,DBP-Br5Cl and DBP-Br4Cl2.
As for the PDBPs, PMBPs are a diverse set of compounds ofwhich the first to be discovered was the perchlorinated MBP-Cl7, orQ1 (2,3,30,4,40,5,50-heptachloro-10-methyl-1,20-bipyrrole). Thiscompound was first described in the late 1990s [71] and has sub-sequently been reported in many species of marine biota particu-larly from the Pacific Ocean, along with PMBPs with bromo- andbromo-chloro- substitution [22,23,70,72e75,208]. Recent workpoints to a microbial source for these compounds based oncompound-specific stable nitrogen determination [75]. Halogena-tion of mono- and dimethylbipyrrole in seawater by ozonolysis hasalso been reported [76]. Approximately 70 mixed bromo- andbromo-chloro- MBP congeners have now been reported in marinemammal blubber and liver collected from the Pacific and AtlanticOceans [72,73,208]. PMBP concentration profiles, with concentra-tions increasing with trophic level strongly suggests that thesecompounds biomagnify similarly to persistent organic pollutants(POPs) [23]. Concentrations of several PMBP congeners, in partic-ular MBP-Br6Cl, in cetaceans and seals from the temperate NorthAtlantic Ocean, were equal to or near concentrations of CB153(about 1 ng g�1 lw). The
P15PMBPs in in blue mussels from the
southern Baltic Sea (Danish Straits) was <0.1e1.9 ng g�1 lw, whilegenerally higher concentrations were found in mussels from theNorth Sea (1.2e14 ng g�1 lw) Compound Q1 accounted for about67e100% of the identified PMBPs [22].
Between 6 and 28 PMBP congeners were identified in nontargetscreening studies of dolphin blubber [29e31]. The
P5PMBPs in
Atlantic common dolphin (Delphinus delphis) blubber was1675 ng g�1 lw, of whichMBP-HBr5Cl2 andMPB-HBr6 accounted for66% and 29% of the total [30]. Compound Q1 (MPB-Cl7) was 5% ofthe total.
While there are no published data for PMBPs in Arctic fauna,their presence is suggested by their occurrence inmarinemammalsfrom adjacent latitudes.
MHC-1 was first detected in seafood from northern Europeanwaters and isolated and fully characterized from a red algae extract[77,209] MHC-1 concentrations from Arctic and Subarctic faunawere 84 and 140 ng g�1 lw respectively, in blubber of Greenlandharp seal (Pagophilus groenlandicus) and hooded seal (Cystophoracristata) from Jan Mayen (71.03� N, 8.29� W) (sampled 1991) [209].Concentrations of MHC-1 in Norwegian coastal fauna collectedbetween 1992 and 2003 were 14e20 ng g�1 lw (egg of white-tailedsea eagle), 1.8e25 ng g�1 ww (shag), 0.24e0.17 ng g�1 ww (bluemussel), and 2.9e13 ng g�1 ww (liver of cod and saithe) [162]. TheMHC-1 concentrationwas 2250 ng g�1 lw in salmon from the FaroeIslands [209]. Average concentrations of MHC-1 ranged from4.1e45 ng g�1 lw in blubber of dolphin species from the Mediter-ranean Sea region [210]. Corresponding concentrations in brainranged from 0.5e3.3 ng g�1 lw. Concentrations of MHC-1 in bluemussels from the southern Baltic Sea and North Sea ranged from0.2e0.7 and 1.7e1893 ng g�1 lw, respectively [22]. The highestconcentrationwas found near Heligoland, where production by theredmacroalga Plocamium cartilagineumwas suspected [209]. MHC-1 in fish from the Mediterranean, Atlantic and Pacific Oceansranged from <2e2260 ng g�1 lw, with the highest concentrations infarmed pollack (Pollachus pollachus) from Denmark (209).
PBHDs were structurally characterized in the Mediterranean
sponge Scalarispongia scalaris and quantified in wild and aquacul-ture fish from the Mediterranean, Atlantic and Pacific Oceans, andin green-lipped mussel (Perna canaliculus) from New Zealand [54].The ranges of
PPBHDs were large, <5e1140 ng g�1 lw in fish, and
220e1570 ng g�1 lw in mussels. The specific compounds in fishwere tribromoBHD (2,7-dibromo-4a-bromomethyl-1,1-dimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthene) and tetrabromo-BHD(2,5,7-tribromo-4a-bromomethyl-1,1-dimethyl-2,3,4,4a,9,9a-hex-ahydro1H-xanthene). Tribromo- and tetrabromo-BHDs were foundin cod liver from Ekne in the Trondheim Fjord, Norway at 0.50 and0.39 ng g�1 ww. Tetrabromo-BHD was found in saithe liver fromSklinna, Norway at 0.89 ng g�1 lw [162]. Tribromo- and tetrabromo-BHDs also occurred in shag from Sklinna, 0.066e0.49 and0.32e5.57 ng g�1 ww respectively in egg; 0.098 to 0.15 and0.049e0.075 ng g�1 ww in liver [162]. In the Mediterranean Sea,tribromo-BHDs, tetrabromo-BHDs and other HNPs were found inblubber of dolphin species at mean levels of
PPBHDs
120e390 ng g�1 lw in blubber and 85e120 ng g�1 lw in brain [210].MHC-1, PBHDs, Q1, and 2,4,6-triBA were found in commercial
fish from European and other sources, including Norwegian andFaroe Island aquaculture operations [175]. Several classes of HNPswere found in highly consumed fish from two bays in southeastBrazil [214]. Fish species were sardine (Sardinella brasiliensis),white-mouthed croaker (Micropogonias furnieri) and mullet (Mugilliza), The compounds and ranges of mean levels in the fish species(ng g�1 lw), were 2,4-diBP (NDe.11), 2,4,6-triBA (3e29), 2,4,6-triBP(1e6), 6-MeO-BDE47 (6e17),20-MeO-BDE68 (2e38) Q1 (7e47),DBP-Br4Cl2 (NDe10) and MHC-1 (NDe19) (detection limits rangedfrom 0.04e2.2 ng g�1 lw, depending on the compound).
PMIs have been identified in nontarget screening of dolphinblubber [30e32]. PMPs were determined in blue mussels from theEuropean Atlantic coast, the North Sea, the Baltic Sea and Chile[211]. Identified compounds were MP-Cl4, MP-BrCl3, MP-Br2Cl2,MP-Br3Cl and MP-Br4. Concentrations of
P4PMPs ranged from
0.5e52 ng g�1. MP-Br4 and two isomers of MP-Br3Cl were the mostabundant congeners.
Polyhalogenated carbazoles (PHCs) have been reported as anenvironmentally relevant class of HNPs, based on their widespreadoccurrence in soils and freshwater sediments [212]. They have beenfound in sediments of Lake Michigan and the Arctic Ocean [15,16].
8. Environmental trends in biota
8.1. Spatial trends
Based on a review of PBDE and MeO-BDE concentrations inmarine mammals globally [190], the ratios of
PPBDEs/
PMeO-
BDEs were about 10:1 in cetaceans from the Northern Hemisphereand 0.1 in the Southern Hemisphere. Greater use of PBDEs in themore industrialized Northern Hemisphere may be partly respon-sible, but sampling location was also a factor. Specimens from theSouthern Hemisphere were collected mainly in tropical regionsnear productive reef areas which were subject to upwelling,whereas those from the Northern Hemisphere were fromtemperate and polar waters.
OH-BDE and PBDE concentrations were similar in eggs of guil-lemot from Iceland, the Faroe Islands and coastal Norway, whereaslevels in eggs of guillemot from Stora Karls€o in the Baltic Properwere many times higher. MeO-BDEs were only detected in theBaltic eggs [185].
PDBP congener profiles (expressed as DBP-BrxCly/P
4PDBPs) inseal species (excluding ringed seals, where levels were low) sug-gested Pacific versus non-Pacific influence. This also extended tothe Arctic, where the congener profile in beluga from Pt. Lay(Alaska) differed from the Canadian Arctic Archipelago and
Svalbard profiles (Fig. 8) [24].Higher concentrations of
P7MeO-BDEs in herring were found at
€Angsk€arsklubb in the Bothnian Sea than at Ask€o in the Baltic Proper[173]. Others have observed higher levels of MeO-BDEs and OH-BDEs in herring from the Bothnian Sea and more northern Both-nian Bay than in the Baltic Proper [174,215]. Reasons for theincreasing south-to-north trend are not clear, but may be related todifferences in production by the regional cyanobacteria and mac-roalgae [173].
8.2. Temporal trends
Changes in MeO-BDE concentrations in marine sediments thatshow no variation over a long time, or trends that are different fromthose of classical POPs such as PCBs and PBDEs, have been invokedas an indication of their natural origin [38,81,138].
POPs in five white-tailed sea eagle eggs from 1996 to 2001collections on the southern Baltic coast were compared with anarchived egg laid in 1941, also on the southern Baltic Sea coast [82].Concentrations of 20-MeO-BDE68 and 6-MeO-BDE47 were virtuallythe same in the 1996e2001 eggs (geometric means 23 and90 ng g�1 lw) and the single 1941 egg (30 and 86 ng g�1 lw). Bycontrast, the geometric mean of
P5PBDEs in the recent eggs was
3120 ng g�1 lw, while PBDE congeners were <2 ng g�1 lw in the1941 egg.
BPs, BAs, MeO-BDEs and OH-BDEs in Baltic algae [37] and bluemussels [164] show strong variations with seasonal productivity.
Haglund et al. [139] found an increasing trend forP
15PBDDs inblue mussels from a station in the Baltic Proper between1995e2003. MeO-BDEs and PBDDs were determined in perchmuscle collected in 1990e2005 from the same station [114]. Nolong-term trends were found, but large fluctuations betweenconsecutive years were observed, up to 5 times for MeO-BDEs and160X for PBDDs, which showed a large spike in 1996 and thenreturned to normal. MeO-BDE concentrations covaried with con-ditions affecting primary productivity: water temperature, watervisibility, nutrients. Short retention of PBDDs due to metabolism,which changes with exposure, may have led to variation in PBDDlevels. Concentrations of OH-BDEs increased in Baltic herring from1980e2010, while fat content and body condition decreased overthat time [173].
In the marine mammals studied by Rotander et al. [109], therewas no clear relationship between the 20-y trends of PBDEs and thetwo monitored biogenic 20-MeO-BDE68 and 6-MeO-BDE47. Stronginter-annual variations in these MeO-BDEs, which showed norelationship to PBDEs, especially in pilot whale and white-sideddolphin, suggested changing exposure in response to varyingproduction.
Concentrations of individual congeners relative to theP
5PDBPswere not significantly correlated to year of collection (1987e 2007)in juvenile male northern fur seals collected from St. Paul Island,Alaska (N. Eisenhardt, pers. comm.). Likewise, the relative propor-tion of the five PDBP isomers was identical in a seal collected in1987 compared to a seal collected in 2007. These observationssupport a natural source of the PDBPs because strong temporaltrends were generally observed for anthropogenic POPs in thesesamples, while there was no trend for the PDBPs.
9. Food web studies
Kelly et al. [101] conducted a study of MeO-BDE bio-magnification in the food web of east Hudson Bay (Canadian Arctic)with samples collected between 1999 and 2003. MeO-BDEs werenot detected in sediment or macroalgae but measurable concen-trations (
P10MeO-BDE) were found in blue mussel (14 ng g�1 lw),
Arctic cod muscle (9.9 ng g�1 lw), sculpin muscle (3.0 ng g�1 lw),salmon muscle (42 ng g�1 lw), eider duck liver (1.3 ng g�1 lw),white-winged scoter liver (2.1 ng g�1 lw), male ringed seal blubber(6.7 ng g�1 lw), and beluga blubber (310, 62 and 300 ng g�1 lw incalves, females and males, respectively) (Fig. 9). The predominantcongeners were 20-MeO-BDE68 and 6-MeO-BDE47. Trophicmagnification factors (TMFs) were calculated for the entire foodweb using the lipid-based concentrations and d15N of organisms inthe food web. The TMFs for 20-MeO-BDE68 and 6-MeO-BDE47were2.3 and 2.6, respectively. These were lower than TMFs of 3e11 forrecalcitrant PCBs, but higher than TMFs of 0.1e1.6 for PBDEs. TheP
10MeO-BDE concentrations exceeded those ofP
31PBDEs inbeluga, salmon and blue mussel while the opposite was the case forother members of the food web.
P10MeO-BDE concentrations were
generally lower than forP
PCBs andP
DDTs, but were comparableto concentrations of other legacy organochlorines such as chloro-benzenes, hexachlorocyclohexanes (HCHs), and chlorinated cyclo-dienes. Compared to the MeO-BDEs, OH-BDEs in the Hudson Bayfood web were orders of magnitude lower or not detected.
The Hudson Bay TMFs are similar to those forP
MeO-BDEs (20-MeO-BDE68 þ 6-MeO-BDE47) and
PPBDEs of 2.9 and 3.9,
respectively, in a Sydney Harbour (Australia) food web, comprisingsquid, crustaceans and fish [216]. Biomagnification factors in aNorth Sea fish to harbor seal or harbor porpoise food web for 20-MeO-BDE68 and 6-MeOBDE47 ranged from 0.1e1.9 and 0.4e23.3,respectively [217]. The transformation capacity appears to behigher for harbor seal than porpoise [217,218].
Accumulation of MeO-BDEs, OH-BDEs, BPs, BAs was followed ina food chain consisting of the red alga Ceramium tenuicorne,amphipod Gammarus sp. prey fish three-spined stickleback andpredator fish perch [161]. The study was done over the summer at asite in the Stockholm Archipelago. MeO-BDEs increased in con-centration from Ceramium< Gammarus< stickleback, then drop-ped dramatically in perch. The opposite pattern was observed forOH-BDEs, where concentrations declined up the food web, butincreased in perch, indicating metabolic demethylation of MeO-BDEs. The ratio of
P7MeO-BDEs/
P7OH-BDEs increased from
Ceramium<Gammarus< stickleback> perch. Debromination wasobserved through the food chain, resulting in higher levels of tetra-brominated MeO-BDE and OH-BDE congeners in fish, whereassome penta- and hexa-brominated congeners dominated inCeramium. The 2,4,6-triBP increased from Ceramium to Gammarus,declined slightly in stickleback and greatly in perch, while 2,4,6-triBA was highest in Ceramium and declined to about 20e50% ofCeramium concentrations up the food chain.
Bioaccumulation of MeO-BDEs and two anthropogenic com-pound classes (PBDEs and chlorinated norbornenes (DechloranePlus and others) was studied in a food web of primary consumers:giant barnacle (Austromegabalanus pstittacus), keyhole limpet(Fisurella sp.), sea squirt (Pyrua chilensis), clams (Venus antiqua,Tagelus dombeii), secondary consumers: crab (Homalaspis plana,Talepus dentata) and fish which are herbivorous or eat small or-ganisms (Peruvian morwong, Cheiodactylus variegatus and damselfish, Chromis crusma) and tertiary consumers: sand perch (Pinguipeschilensis) and Chilean abalone (Concholepas concholepas) in acoastal area off south central Chile (36.75 oS, 72.17 oW) [219]. TheP
8PBDEs ranged from 11 to 111 ng g�1 lw in primary consumers,14e170 ng g�1 lw in secondary consumers, and 13e69 ng g�1 lw intertiary consumers. The
P8MeO-BDEsranged from NDe49 ng g�1
lw in primary consumers, NDe37 ng g�1 lw in secondary con-sumers, and 0.5e118 ng g�1 lw in tertiary consumers (detectionlimits not given). The proportions of total measured organohalogenresidues of
P8PBDEs,
P8Me-BDEs and
P3DPs were 81.6, 15, and
3.4% in primary consumers, 83, 16.6, and 0.4% in secondary con-sumers, and 51.6, 48, and 0.4% in tertiary consumers. Thus, the
Fig. 9. TheP
15PBDEs andP
10MeO-BDEs in the food web of eastern Hudson Bay and Hudson Strait, Canada. Tissues: m¼muscle, l¼ liver, b¼ blubber. (Drawn from data in Kellyet al., 2008 [101].
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e115108
proportion of MeO-BDEs to total organohalogens increased up thefood web. Biomagnification factors (BMFs) were >1 for severalpredator/prey pairs and in general higher for MeO-BDEs thanPBDEs.
PDBPs were examined in the Arctic food web of the NorthwaterPolynya in the eastern Canadian Arctic (76�N to 79�N and 70�W to80�W) during 1998 [25]. The food web consisted of zooplankton(Calanus hyperboreus,Mysis oculata, and Sagitta sp.), one fish [Arcticcod (Boreogadus saida)], four seabirds [dovekie (Alle alle), blackguillemot (Cepphus grylle), black-legged kittiwake (Rissa tridactyla),and glaucous gull (Larus hyperboreus)], and one marine mammal[ringed seal (Pusa hispida)]. Compounds determined were DBP-Br3Cl3, DBP-Br4Cl2, DBP-Br5Cl and DBP-Br6. Mean concentrations ofP
4PDBPs in the zooplankton were 0.021e0.93 ng g�1 lw. PDBPswere also found in all bird species, with
P4PDBP concentrations in
the order glaucous gull (68 ng g�1 lw)> blacklegged kittiwake(32 ng g�1 lw)> black guillemot (9.6 ng g�1 lw)> dovekie(3.2 ng g�1 lw), and Arctic cod (1.1 ng g�1 lw). The
PPDBP con-
centration in ringed seal was 0.14 ng g�1 lw and only three conge-ners were present. TMFs (excluding the seal data) were 14.6 (DBP-Br4Cl2)> 7.0 (DBP-Br6)¼ 6.9 (DBP-Br5Cl)> 5.2 (DBP-Br3Cl3). Thesewere comparable to the TMF of 9.8 for CB-153 observed in the samefood web [220], indicating that PDBPs are highly bioaccumulative.The very low concentrations observed in ringed seal relative toother organisms at a similar trophic level strongly suggestedmetabolism of the PDBPs by seals.
10. Toxic effects of HNPs
It is beyond the scope of this review to thoroughly survey hu-man and ecosystem exposure to HNPs, and how they elicit toxi-cological responses. A brief discussion and relevant articles arementioned in this section.
Many HNPs have been screened for biological activity and someare effective as pharmaceuticals [4,39,40]. Thus, even though HNPsare natural compounds, they are rightly considered as “chemicals ofemerging concern”. Do they augment stresses when in mixturewith toxic anthropogenic chemicals?
Unlike POPs, which continue to decline in the physical andbiological environments [20,21], anthropogenic chemicals in cur-rent use can be considered “pseudopersistent” or “continuously
present” if they are continuously released into the environment[221]. Such a scenario also applies to HNPs, which are synthesizedwithin the aquatic system and present continuous, albeit periodic,exposure to organisms. Moreover, there are reasons to expectfuture increase in HNPs release (Section 11).
Research on the toxicology of HNPs has largely focused on thebromophenolic compounds. PBDEs impact the thyroid system, areneurotoxic and endocrine disruptors, and OH-BDEs appear to actsimilarly [111,222e225]. Toxic effects have also been demonstratedfor 2,4,6-triBP, including binding to the human thyroid transportprotein transthyretin (TTR) [226] and hormonal effects in fish[226,227]. These and other aspects of 2,4,6-TriBP toxicology wererecently reviewed [228]. OH-BDEs disrupt oxidative phosphoryla-tion [229,230] and interfere with human placental aromatase [231].MeO-BDEs themselves show endocrine disrupting effects [232],and are of concern especially because they bioaccumulate andbecome metabolized to the more toxic OH-BDEs [111]. Some HNPshave the ability to cross the blood-brain barrier [210]. MeO-BDEsand OH-BDEs bind to the aryl hydrocarbon (Ah) receptor and havebeen assigned potencies to avian species relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) [233]. Relatively high MeO-BDEs and OH-BDEs in the serum of Japanese women were relatedto consumption of local fish and macroalgae [234].
PBDDs contribute to human exposure to total TCDD toxicequivalents (TEQ) [235]. The relative potency of PBDDs to TCDDmeasured in in eel and crab collected on the west coast of Swedenwere close to the European Union maximum residue limits (MRLs)for PCDD/Fs in food, while they exceeded the MRL by 100-fold inmussels from the Baltic proper [139]. Other studies have found onlyminor contribution of PBDD/Fs TEQ in Baltic salmon [178] andringed seal [198] compared to their anthropogenic chlorinatedanalogs. Different congeners were determined in the these studies,the more abundant triBDDs [139] versus less abundant tetra- andhigher BDDs [178,198], and also to differences in metabolism ofPBDDs by these organisms.
Far less information is available on the effects of PMBPs andPDBPs. Congeners of both chemical classes bioaccumulate (Sections7-9). TMFs for PDBPs are similar to those of anthropogenic POPs[25]. PDBPs bind to the Ah receptor and induce CYP P4501A [236].On the other hand, an in-vitro study showed that high concentra-tions of Q1 inhibited binding of TCDD to the human Ah receptor
[27]. Polyhalogenated carbazoles (PHCs) also show dioxin-typetoxicity [212].
11. Potential impacts of climate change on HNP productionand distribution
Much has been written about the impacts of climate change onthe transport and fate of POPs [237e244] and how such changesmay affect bioaccumulation and temporal trends in biota[21,245e250]. By contrast, these links are virtually unexplored forhighmolecular weight HNPs. There are reasons why climate changemight affect HNPs differently from conventional POPs. Firstly, theprimary sources of HNPs are in oceans and seas where they areproduced. POPs are generated on land by human activities, withsecondary emissions from contaminated soil and water. Secondly,many factors affecting the production of HNPs are likely to changewith climate, including the amount and quality of DOM, salinity,phytoplankton and heterotrophic bacteria, type and distribution ofmacroalgae species. The role of these factors in biosynthesis of highmolecular weight HNPs is largely unexplored.
Production of halocarbons in the ocean is related to photosyn-thetic biomass [251] and DOM [252,253], and in the Arctic Ocean tohigher levels of DOM in the Transpolar Drift and brine pockets insea ice [132]. Biological production of halocarbons is also importantin sea ice of the Southern Ocean [254,255]. The concentrations ofhalocarbons in Arctic Ocean surface waters do not appear to havechanged much over the last two decades [132]. The future could bedifferent, with changes in river runoff, precipitation and loss of icecover; affecting primary production, species composition, circula-tion patterns, formation of halocline water and air-sea exchange[132]. The levels and composition of DOM entering Arctic rivers arelikely to change with permafrost melting releasing “old” carbonand shifts in vegetation which produce different lignin types [256].Response of halocarbon production to ocean acidification (as indi-cated by the partial pressure of CO2) were subtle or undetectable,however the decrease in the extent of summer sea ice is expected toresult in an increase in photosynthetically active radiation at thesea surface and primary production [257]. Thus, the role of halo-carbons in Arctic atmospheric chemistry may increase with loss ofice cover [258]. Freshening of the Polar Mixed Layer is an unknownfactor which might affect bromocarbon production by limiting theavailability of bromide. In laboratory experiments, the bromoper-oxidase activity of the Arctic diatom Porosira glacialis increasedfrom nearly zero at 5 mmol L�1 bromide to a plateau at900e1500 mmol L�1 [259]. About 80% of the plateau activity wasreached at a bromide concentration of 600 mmol L�1. The bromidecontent of 35‰ seawater is 860 mmol L�1.
Whether these factors are also relevant for production of highermolecular weight HNPs remains to be seen. There appears to beonly one report of salinity effects on BP production [37]. Formationof 2,4,6-triBP by Ceramium tenuicorne from the Baltic Properincreased with salinity in the range was 5e9‰. Paradoxically, fe-male clones from brackish water in the Baltic produced more 2,4,6-triBP than clones from the Oslo Fjord (20e25‰). No investigationshave been made of BPs generated by the action of bromoperox-idases on DOM, but by analogy to halocarbons [259] such apathway could be conceived. If so, increased riverine discharge ofterrestrial DOM and transport in the Transpolar Drift may stimulateproduction of higher HNPs. Terrestrial humic acids were found toenhance peroxidase-mediated production of halocarbons inseawater [253].
The discovery that marine bacteria synthesize bromophenoliccompounds [5e7] has implications for climate change impact.Changes expected in the northern Baltic Sea include warmer tem-peratures, increased precipitation and increased river runoff of
water containing terrestrial DOM, with consequences of reducedsalinity and phytoplankton production, and increased heterotro-phic bacteria [260,261]. On one hand, lower phytoplankton andsalinity may decrease synthesis of HNPs, whereas higher bacteriamay cause an increase. The net result remains unknown [262].Climate change in the Baltic is also expected to cause changes inmacroalgae species abundance and distribution in the Baltic Sea[263].
Like halocarbons, air-sea exchange of BAs in the Arctic Oceanwould be enhanced by loss of ice cover. HNPs originate within theocean and long-range transport to the Arctic via currents is a pos-sibility. Oceanic transport is expected for some perfluorinatedcompounds [264,265], currently used pesticides [266] and POPs[267,268] which are persistent, relatively water soluble and haveintermediate volatility.
12. Conclusions and recommendations
HNPs existed before industrial production of anthropogenicorganohalogens and the roles of these compounds in ecosystemfunctioning are still being investigated and debated. The diversityof HNPs is immense e over 5000 compounds have so far beenidentified [4]. These range in complexity from simple, low molec-ular weight halocarbons to large compounds with molecularweights in the same range as those of POPs.
HNPs are rightly categorized as “chemicals of emergingconcern”. They are produced in the environment and “pseudo-persistent”, presenting a continual exposure to biota. Biologicalactivity is attributed to many HNPs and some elicit toxic responsessimilar to those of PBDEs and PCDD/Fs. It is thus important toevaluate HNPs in mixture with anthropogenic compounds. Pro-duction, transport and distribution of HNPs are likely to be stronglyaffected by climate change impacts on the physical and biologicalsystems.
Analytical methods for conventional POPs are suitable for someHNPs, while special considerations are required for others. Theextra steps needed to release OH-BDEs from binding to lipids inmussels is an exemplary case [166]. Other examples of extra careneeded: PBDDs are easily debrominated by UV radiation [140] andprotection during analytical procedures is warranted. PBHDs aresusceptable to degradation in the GC injection unless the liner isscrupulously clean [54], and separation of OH-BDEs from PBDDsbefore GC analysis is necessary to prevent cyclization of OH-BDEs toPBDDs in the injection port.
Higher molecular weight HNPs are found at all levels of Arctic-Subarctic ecosystems. The bulk of research has focused on thebromophenolic compounds: BPs, BAs, MeO-BDEs and OH-BDEs,with less attention given to PBDDs and HNPs with heterocyclicring structures (e.g., PDBPs, PMBPs, PBHDs, PMIs, PHCs). Althoughreports of these in Arctic biota are scarce or non-existent, theirlikely presence can be inferred from occurrence in the Baltic Sea,other and seas/oceans and freshwater ecosystems at temperate andtropical latitudes.
Measurements of bromophenolic HNPs in the Arctic havemainly been carried out on seabird and marine mammal species,with fewer investigations of fish and invertebrates. It seems likelythat Arctic macroalgae and phytoplankton would produce thesecompounds, given their widespread occurrence in the Baltic Sea,Atlantic coasts of Sweden and Norway, and other marine areas.However, there are very few studies in the Arctic. Reports of HNPtrophic transfer of HNPs in the Arctic and Baltic Sea are sparse.
Temporal/spatial trends are poorly known relative to anthro-pogenic POPs. There have been some studies of metabolic trans-formations, such as for MeO-BDEs, OH-BDEs and PBDEs, but not forother compounds. Many biosynthetic pathways and subsequent
T.F. Bidleman et al. / Emerging Contaminants 5 (2019) 89e115110
transformation mechanisms have been identified for higher mo-lecular weight HNPs. Work in this area has been largely confined totemperate and tropical ecosystems, with little attention paid to thepolar regions, even though it is apparent that HNPs are found there.
Measurements of HNPs in abiotic samples are lacking. Very littleis known about production of higher molecular weight HNPs inArctic-Subarctic and Baltic ecosystems, but relevant factors arelikely to be similar to those for halocarbons. It is not known if HNPsother than halocarbons are produced or occur in snow and ice,although BAs were reported in snow from southern Sweden andArctic Finland. Similar to halocarbons, air-sea exchange of HNPswould be enhanced by a loss of ice cover.
Widespread occurrence and high diversity of HNPs in ArcticOcean sediments is testimony to formation in situ, or facile trans-port from temperate latitudes. The relative importance of HNPbiosynthesis within the Arctic versus delivery by atmospheric andoceanic currents is unknown. If these external processes areimportant, levels of HNPs in the Arctic may also respond to changesin temperate and tropical oceans. Atmospheric transport is sug-gested by the presence of MeO-BDEs and/or OH-BDEs in precipi-tation and biota from inland lakes and rivers, although biosynthesisfrom available bromine in terrestrial and lentic ecosystems cannotbe ruled out. The possibility of delivery by ocean currents is sug-gested by different congener profiles of PDBPs in beluga fromAlaska versus the Canadian Arctic Archipelago and Svalbard.
Acknowledgements
Support to TFB was provided by the Swedish Research Envi-ronment EcoChange. LMJ acknowledges support for an exchangevisit to Umeå University from ARCUM, the Arctic Research Instituteat Umeå University. Disclaimer: Certain commercial equipment orinstruments are identified in the paper to specify adequately theexperimental procedures. Such identification does not imply rec-ommendations or endorsement by the National Institute of Stan-dards and Technology; nor does it imply that the equipment orinstruments are the best available for the purpose. Any use of trade,firm, or product names is for descriptive purposes only and doesnot constitute endorsement by the U.S. Government.
Appendix A. Supplementary data
Supplementary data to this article can be found online athttps://doi.org/10.1016/j.emcon.2019.02.007.
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a) Properties are at 25 oC unless stated otherwise (see ref. 6 and 8). See Table 1 for compound abbreviations.
5
References and methods1. Kuramochi et al., 2004. Experimental water solubility (shake flask, generator column), K OW (HPLC retention time),
predicted vapor pressure, K OA and K AW .
2. Calculated from other properties using K AW = P L /(S L *RT ), K OA = K OW /K AW .
3. Pfeifer et al., 2001. Experimental vapor pressure (GC-retention time), K OW and water solubility (HPLC retention time),
predicted KOW and K OA ).
4. Bidleman et al., 2016. Experimental (bubble stripping).5. Vetter et al., 2004. Experimental vapor pressure (GC-retention time) and water solubility (generator column), predicted K AW .
6. Diaz et al., 2007, Experimental (solid-phase microextraction headspace analysis, 22 oC).7. Rayne and Forest, 2010, predicted by SPARC. Authors give pK A values for all 209 congeners.
8. Yu et al., 2008. Experimental (HPLC retention time) or predicted.
9. Zhao et al., 2010. Experimental (GC-retention time).
10. Zhao et al., 2016. Experimental (GC-retention time).
11. Arnoldsson 2012. Predicted.
12. Tittlemier et al., 2004. Experimental vapor pressure (GC-retention time), water solubility (generator column), K OW (slow-stir method).
13. Hackenberg et al., 2003. GC-retention time.
6
Reference list
Arnoldsson, K. 2012. Polybrominated dibenzo-p-dioxins – Natural formation mechanisms and biota retention, maternal transfer, and effects. Ph.D. thesis, Department of Chemistry, Umeå University, Umeå, Sweden, ISBN 978-91-7459-353-2, 65 pp. Bidleman, T.F.; Agosta, K.; Andersson, A.; Haglund, P.; Hegmans, A.; Liljelind, P.; Jantunen, L.M.; Nygren, O.; Poole, J.; Ripszam, M.; Tysklind, M. 2016. Sea-air exchange of bromoanisoles and methoxylated bromodiphenyl ethers in the Northern Baltic. Mar. Pollut. Bull. 112, 58-64. Diaz, A.; Ventura, F.; Galceran, M.T. 2007. Determination of Henry’s law constants for low volatile mixed halogenated anisoles using solid-phase microextraction. Anal. Chim. Acta 589, 133-136. Hackenberg, R., Schütz, A., Ballschmiter, K. 2003. High-resolution gas chromatography retention data as basis for the estimation of Kow values using PCB congeners as secondary standards. Environ. Sci.Technol. 37, 2274–2279. Kuramochi, H.; Maeda, H.; Kawamoto, K. 2004. Water solubility and partitioning behavior of brominated phenols. Environ. Toxicol. Chem. 23, 1386-1393. Pfeifer, O.; Lohmann, U.; Ballschmiter, K. 2001. Halogenated methyl-phenyl ethers (anisoles) in the environment: determination of vapor pressures, aqueous solubilities, Henry’s law constants, and gas/water- (Kgw), n-octanol/water- (Kow) and gas/n-octanol- (Kgo) partition coefficients. Fres. J. Anal. Chem. 371, 598-606. Rayne, S.; Forest, K. 2010. pKa values of the monohydroxylated polychlorinated biphenyls (OH-PCBs), polybrominated biphenyls (OH-PBBs), polychlorinated diphenyl ethers (OH-PCDEs), and polybrominated diphenyl ethers (OH-PBDEs). J. Environ. Sci. Health A 45, 1322-1346. Tittlemier, S.A.; Braekevelt, E.; Halldorson, T.; Reddy, C.M.; Norstrom, R.J. 2004. Vapour pressures, aqueous solubilities, Henry’s law constants, and octanol/water partition coefficients of a series of mixed halogenated dimethyl bipyrroles. Chemosphere 57, 1373-1381. Vetter, W.; Hahn, M.E.; Tomy, G.; Ruppe, S.; Vatter, S.; Chahbane, N.; Lenoir, D.; Schramm, K.-W.; Scherer, G. 2004. Biological activity and physicochemical parameters of marine halogenated natural products 2,3,3’,4,4’,5,5’-heptachloro-1’-methyl-1,2’-bipyrrole and 2,4,6-tribromoanisole. Arch. Environ. Contam. Toxicol. 48, 1-9. Yu,Y.; Yang, W.; Gao, Z.; Lam, M.H.W.; Liu, X.; Wang, L.; Yu, H. 2008. RP-HPLC measurement and quantitative structure–property relationship analysis of the n-octanol–water partitioning coefficients of selected metabolites of polybrominated diphenyl ethers. Environ. Chem. 5, 332.339. Zhao, H.; Xie, Q.; Tan, F.; Chen, J.; Quan, X.; Qu, B.; Zhang, X.; Li, X. 2010. Determination and prediction of octanol–air partition coefficients of hydroxylated and methoxylated polybrominated diphenyl ethers. Chemosphere 80, 660-664. Zhao, H.; Xie, Q.; Chen, X.; Qu, B.; Jiang, J. 2016. Measurement of temperature dependence for vapor pressures of seventeen OH-PBDEs and eleven MeO-PBDEs by
gas chromatographic method. Bull. Environ. Contam. Toxicol. 96, 657-663.1
7
Table S2. Bromophenolic HNPs and PBDEs in fish from arctic-subarctic waters and the Baltic Seaa,b
, ng g-1
.
Common Scientific lipid (L) or
name name Location Year Tissue wet (W) wt. BDE-47 ΣPBDEscΣBPs-BAs
c6-47 2'-68 ΣMeO-BDEs
c6-47 2'-68 ΣOH-BDEs
cΣPBDD/Fs
cReference
Salmon Salmo sp. Hudson Bay, Canada 1999-2003 muscle L 9.3 34 6.1 42 ND 1
Salmon Salmo salar Hraunsfjord, Iceland 1998 whole body L 7.6 12.0 3.0 2
Salmon Salmo salar Norway, aquaculture 2004 muscle L 18 3
Cod Gadus morhua Baltic Sea 2013 liver L 21 58 5.4 2.8 0.0084 14
Stickleback Gasterosteus aculeatus Baltic Sea 2013 whole body L 678 262 36 302 24 20 101 13
Eel Anguilla anguilla Baltic Sea 2000-2004 muscle (L)d
0.24 12
a) PBDEs are only reported for studies which also include HNPs.
b) Single numbers are arithmetic means, geometric means or medians.
c) See references for number of congeners sought and found, and detection/quantitation limits.
d) Estimated from reported wet weight concentration, using lipid percentages given in the paper or assumed from other works.
PBDEs MeO-BDEs OH-BDEs
9
Reference list
1. Kelly, B.C.; Ikonomou, M.G.; Blair, J.D.; Gobas, F.A.P.C. 2008. Hydroxylated and methoxylated polybrominated diphenyl ethers in a Canadian Arctic marine food web. Environ. Sci. Technol. 42, 7069-7077.
2. Sinkkonen, S.; Rantalainen, A.L.; Paasivirta, J.; Lahtipera, M. 2004. Polybrominated methoxy- diphenyl ethers (MeO-PBDEs) in fish and guillemot of Baltic,
Atlantic and Arctic environments. Chemosphere 56, 767-75.
3. Hiebl, J.; Melcher, J.; Gunderson, H.; Schlabach, M.; Vetter, W. 2006. Identification and quantification of polybrominated hexahydroxanthene derivatives and other halogenated natural products in commercial fish and other marine samples. J. Agric. Food Chem. 54, 2652-2657.
4. Vetter, W.; von der Recke, R.; Herzke, D.; Nygård, T. 2007a. Natural and man-made organobromine compounds in marine biota from Central Norway,
Environ. Internat. 33, 17-26.
5. Schlabach, M.; Remberger, M.; Brorström-Lundén, E.; Norström, K.; Kaj, L.; Andersson, H.; Herzke, D.; Borgen, A.; Harju, M. 2011. Brominated Flame Retardants in the Nordic Environment. TemaNord 2011:528, Nordic Council of Ministers, Copenhagen 2011, ISBN 978-92-893-2221-8, 86 pp.
6. Strid, A.; Athanassiadis, I.; Athanasiadou, M.; Svavarsson, J.; Päpke, O.; Bergman, Å. 2010. Neutral and phenolic brominated organic compounds of natural
and anthropogenic origin in northeast Atlantic Greenland shark (Somniosus microcephalus). Environ. Toxicol. Chem. 29, 2653-2659.
7. Haglund, P.S.; Zook, D.R.; Buser, H.-R.; Hu, J. 1997. Identification and quantification of polybrominated diphenyl ethers and methoxy-polybrominated diphenyl ethers in Baltic biota. Environ. Sci. Technol. 31, 3281-3287.
8. Dahlberg, A.-K.; Bignert, A.; Legradi, J.; Legler, J.; Asplund, L. 2016b. Anthropogenic and naturally produced brominated substances in Baltic herring (Clupea
harengus membras) from two sites in the Baltic Sea. Chemosphere 144, 2408-2414.
9. Kierkegaard, A.; Bignert, A.; Sellström, U.; Olsson, M.; Asplund, L. Jansson, B.; deWit, C. 2004. Polybrominated diphenyl ethers (PBDEs) and their methoxylated derivatives in pike from Swedish waters with emphasis on temporal trends, 1967-2000. Environ. Pollut. 130, 187-198.
10. Zacs, D.; Rjabova, J.; Bartkevics, V. 2013. Occurrence of brominated persistent organic pollutants (PBDD/DFs, PXDD/DFs, and PBDEs) in Baltic wild salmon (Salmo salar) and correlation with PCDD/DFs and PCBs. Environ. Sci. Technol. 47, 9478-9484.
11. Haglund, P.; Löfstrand, K.; Malmvärn, A.; Bignert, A.; Asplund, L. 2010. Temporal variations of polybrominated dibenzo-p-dioxin and methoxylated diphenyl ether concentrations in fish revealing large differences in exposure and metabolic stability. Environ. Sci. Technol. 44, 2466-2473.
10
12. Haglund, P.; Malmvärn, A.; Bergek, S.; Bignert, A.; Lautsky, L.; Nakano, T.; Wiberg, K.; Asplund, L. Brominated dibenzo-p-dioxins: a new class of marine toxins? 2007. Environ. Sci. Technol. 41, 3069-3074.
13. Dahlgren, E.; Lindqvist, D.; Dahlgren, H.; Asplund, L.; Lehtilä, K. 2016. Trophic transfer of naturally produced brominated aromatic compounds in a Baltic Sea food chain. Chemosphere 144, 1597-1604.
14. Roszko,M.; Szymczyk, K.; Rzepkowska, M.; Jedrzejczak, R. 2015. Preliminary study on brominated dioxins/furans and hydroxylated/methoxylated PBDEs in Baltic cod (Gadus morhua) liver. Comparison to the levels of analogue chlorinated co-occurring pollutants. Mar. Pollut. Bull. 96, 165-175.
11
Table S3. Bromophenolic HNPs and PBDEs in birds from arctic-subarctic regions and the Baltic Seaa,b
, ng g-1
.
Common Scientific lipid (L) or
name name Location Year Tissue wet (W) wt. BDE-47 ΣPBDEsc
ΣBPs-BAsd
6-47 2'-68 ΣMeO-BDEsc
6-47 2'-68 ΣOH-BDEsc
ΣPBDDsc
Reference
white winged Melanitta fusca Hudson Bay, Canada liver L 71 2.0 0.22 2.1 ND 1
scoter ND
eider duck Somateria Hudson Bay, Canada 1999-2003 liver L 20 0.86 0.29 1.3 ND 1
mollissima coastal Norway 2012 egg (L)f
ND 9.2 58 2
white-tailed Haliaeetus albicilla East Greenland 1999-2009 liver L 98 180 20 8.7 29 3
sea eagle East Greenland muscle L 213 420 23 18 41 3
f) Estimated from reported wet weight concentration, using lipid percentages given in the paper or assumed from other works.
PBDEs MeO-BDEs OH-BDEs
13
Reference list
1. Kelly, B.C.; Ikonomou, M.G.; Blair, J.D.; Gobas, F.A.P.C. 2008. Hydroxylated and methoxylated polybrominated diphenyl ethers in a Canadian Arctic marine food web. Environ. Sci. Technol. 42, 7069-7077.
2. Huber, S.; Warner, N.A.; Nygard, T.; Remberger, M.; Harju, M.; Uggerud, H.T.; Kai, L.; Hanssen, L. 2015. A broad cocktail of environmental pollutants found in egg of three seabird species from remote colonies in Norway. Environ. Toxicol. Chem. 34, 1296-1308.
3. Jaspers, V.; Jaspers, V.L.B.; Sonne, C.; Soler-Rodriguez, F.; Boertmann, D.; Dietz, R.; Eens, M.; Rasmussen, L.M.; Covaci, A. 2013. Persistent organic pollutants and methoxylated polybrominated diphenyl ethers in different tissues of white-tailed eagle (Haliaeetus albicilla) from West Greenland. Environ. Pollut. 175, 137-146.
4. Nordlöf, U.; Helander, B.; Bignert, A.; Asplund, L. 2010. Levels of brominated flame retardants and methoxylated polybrominated diphenyl ethers in egg of
white-tailed sea eagle breeding in different regions of Sweden. Sci. Total Environ. 409, 238-246.
5. Verreault, J.; Shahmiri, S.; Gabrielsen, G.W.; Letcher, R.J. 2007a. Organohalogen and metabolically-derived contaminants and associations with whole body constituents in Norwegian Arctic glaucous gull. Environ. Internat. 33, 823-830.
6. Verreault, J.; Gabrielsen, G.W.; Chu, S.; Muir, D.C.G.; Andersen, M.; Hamaed, A.; Letcher, R.J. 2005. Flame retardants and methoxylated and hydroxylated polybrominated diphenyl ethers in two Norwegian Arctic top predators: glaucous gull and polar bears. Environ. Sci. Technol. 39, 6021-6028.
7. Verreault, J.; Bech, C.; Letcher, R.J.; Ropstad, E.; Dahl, E.; Gabrielsen, G.W. 2007b. Organohalogen contamination in breeding glaucous gull from the Norwegian Arctic: associations with basal metabolism and circulating thyroid hormones. Environ. Pollut. 145, 138-45.
8. Verreault, J.; Gebbink, W.A.; Gauthier, L.; Gabrielsen, G.W.; Letcher, R.J;. 2007c. Brominated flame retardants in glaucous gull from the Norwegian Arctic: more than just an issue of polybrominated diphenyl ethers. Environ. Sci. Technol. 41, 4925-4931.
9. Jörundsdottir. H.; Bignert, A.; Svavarsson, J.; Nygård. T.; Weihe, P.; Bergman, Å. 2009.Assessment of emerging and traditional halogenated contaminants in guillemot (Uria aalge) egg from North-Western Europe and the Baltic Sea. Sci. Total Environ. 407, 4174-4183.
10. Schlabach, M.; Remberger, M.; Brorström-Lundén, E.; Norström, K.; Kaj, L.; Andersson, H.; Herzke, D.; Borgen, A.; Harju, M. 2011. Brominated Flame Retardants in the Nordic Environment. TemaNord 2011:528, Nordic Council of Ministers, Copenhagen 2011, ISBN 978-92-893-2221-8, 86 pp.
11. Knudsen, L.B.; Borgå, K.; Jørgensen , E.H.; van Bavel, B.; Schlabach, M.; Verreault, J.; Gabrielsen, G.W. 2007. Halogenated organic contaminants and mercury in northern fulmars (Fulmarus glacialis): levels, relationships to dietary descriptors and blood to liver comparison. Environ. Pollut. 146, 25-33.
14
12. Vetter, W.; von der Recke, R.; Herzke, D.; Nygård, T. 2007a. Natural and man-made organobromine compounds in marine biota from Central Norway, Environ. Internat. 33, 17-26.
13. Nordlöf, U.; Helander, B.; Eriksson, U.; Zebühr, Y.; Asplund, L. 2012. Comparison of organohalogen compounds in a white-tailed sea eagle egg laid in 1941 with five eggs from 1996 to 2001. Chemosphere 88, 286-291.
14. Sinkkonen, S.; Rantalainen, A.L.; Paasivirta, J.; Lahtipera, M. 2004. Polybrominated methoxy- diphenyl ethers (MeO-PBDEs) in fish and guillemot of Baltic, Atlantic and Arctic environments. Chemosphere 56, 767-75.
15. Dahlberg, A.-K.; Lindberg, Chen, V.; Larsson, K.; Bergman, Å.; Asplund, L. 2016. Hydroxylated and methoxylated polybrominated diphenyl ethers in long-tailed ducks (Clangula hyemalis) and their main food, Baltic blue mussels (Mytilus trossulus × Mytilus edulis). Chemosphere 144, 1475-1483.
15
Table S4. Bromophenolic HNPs and PBDEs in arctic and subarctic marine mammalsa,b
, ng g-1
.
Common Scientific lipid (L) or
name name Location Year Tissue wet (W) wt. PBDE-47 ΣPBDEsc
ΣBPs-BAsd
6-47 2'-68 ΣMeO-BDEsc
6-47 2'-68 ΣOH-BDEsc
ΣPBDD/Fsc
Reference
beluga whale Delphinapterus leucas Hudson Bay, Canada
dolphin, M Faroe Islands 2001-2002 blubber L 204-221 906-1021 220-438 13-14 3
Faroe Islands 1997 blubber L 70-110 333-425 5.6-195 1.6-8.4 3
polar bear, MF Ursus maritimus E. Greenland 1999-2001 adipose (L)e
92 ND-28 1.0 9
MF E. Greenland 1999-2001 blood (L)e
92 ND-60 223 9
MF E. Greenland 1999-2001 brain (L)e
14 ND ND 9
MF E. Greenland 1999-2001 liver (L)e
364 ND ND 9
F Norwegian arctic 2002 plasma (L)e
498 538 ND-17 ND-54 10
MF Alaska, U.S.A. 1993-2002 liver (L)e
11 1.9 0.37 0.15 11
a) PBDEs are only reported for studies which also include HNPs.
b) Single numbers are arithmetic means, geometric means or medians.
c) See references for number of congeners sought and found.
d) 2,4,6-TriBA.
e) Estimated from reported wet weight concentration, using lipid percentages given in the paper or assumed from other works.
PBDEs MeO-BDEs OH-BDEs
17
Reference list
1. Kelly, B.C.; Ikonomou, M.G.; Blair, J.D.; Gobas, F.A.P.C. 2008. Hydroxylated and methoxylated polybrominated diphenyl ethers in a Canadian Arctic marine food web. Environ. Sci. Technol. 42, 7069-7077.
2. McKinney, M.; De Guise, S.; Martineau, D.; Béland, P.; Lebeuf, M.; Letcher, R.J. 2006. Organohalogen contaminants and metabolites in beluga whale (Delphinapterus leucas) liver from two Canadian populations. Environ. Toxicol. Chem. 25,1246–1257.
3. Rotander, A.; van Bavel, B.; Polder, A.; Rigét, F.; Auðunsson, G.A.; Gabrielsen, G.W.; Víkingsson, G.; Bloch, D.; Dam, M. 2012b. Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986–2009. Environ. Internat. 40, 102-109.
4. Hoydal, K.S.; Letcher, R.J.; Blair, D.A.D.; Dam, M.; Lockyer, C.; Jenssen, B.M. 2015. Legacy and emerging organic pollutants in liver and plasma of long-finned pilot whales (Globicephala melas) from waters surrounding the Faroe Islands Sci. Total Environ. 520, 270-285.
5. Bjurlid, F.; Dam, M.; Hoydal, K.; Hagberg, J. 2018a. Occurrence of polybrominated dibenzo-p-dioxins, dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) in pilot whales (Globicephala melas) caught around the Faroe Islands. Chemosphere 195, 11-20.
6. Letcher, R.J.; Gebbink, W.A.; Sonne, C.; Erik W. Born, E.W.; McKinney, M.A.; Dietz, R. 2009. Bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from East Greenland. Environ. Internat. 35, 1118-1124.
7. Routti, H.; Letcher, R.J.; van Bavel, B.; Arukwe, A.; Chu, S-G.; Gabrielsen, G.W. 2009. Polybrominated diphenyl ethers and their hydroxylated analogues in ringed seals (Phoca hispida) from Svalbard and the Baltic Sea. Environ. Sci. Technol. 43:3494–3499.
8. Bjurlid, F.; Roos, A.; Ericson Jogsten, I.; Hagberg, J. 2018b. Temporal trends of PBDD/Fs, PCDD/Fs, PBDEs and PCBs in ringed seals from the Baltic Sea (Pusa hispida botnica) between 1974 and 2015. Sci. Total Environ. 616-617, 1374-1383.
9. Gebbink, W.A.; Sonne, C.; Dietz, R.; Kirkegaard, M.; Riget, F.F.; Born, E.W.; Muir, D.C.G.; Letcher, R.J.. 2008. Tissue-specific congener composition of organohalogen and metabolite contaminants in East Greenland Polar Bears (Ursus maritimus). Environ. Pollut. 152, 621-629.
10. Verreault, J.; Gabrielsen, G.W.; Chu, S.; Muir, D.C.G.; Andersen, M.; Hamaed, A.; Letcher, R.J. 2005. Flame retardants and methoxylated and hydroxylated polybrominated diphenyl ethers in two Norwegian Arctic top predators: glaucous gull and polar bears. Environ. Sci. Technol. 39, 6021-6028.
11. Wan, Y.; Wiseman, S.; Chang, H.; Chorney, D.; Zhang, X.; Jones, P. D.; Hecker, M.; Kannan, K.; Tanabe, S.; Hu, J.; Lam, M. H. W.; Giesy, J. P. 2009. Origin of hydroxylated brominated diphenyl ethers: Natural compounds or man-made flame retardants? Environ. Sci. Technol. 43, 7536−7542.
