Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, naphthalenes and polybrominated diphenyl ethers in the edible fish caught from the Baltic Sea and lakes in Finland

A total of 156 fish composite samples were collected from five areas of the Baltic Sea and from three lakes and analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polybrominated diphenyl ethers (PBDEs). The European Union's maximum permissible level for PCDD/Fs, 4 pg WHO-TEQ/g fresh weight (fw), was exceeded in salmon, river lamprey and Baltic herring. In other species from the Baltic Sea, the 90th percentile was 3.42 pg WHO(PCDD/F)-TEQ/g fw. In the lake fish, the concentrations of PCDD/Fs, PCBs and PCNs were only 29-46% of those in the same species caught from the Baltic Sea, whereas the concentrations of PBDEs in the lake fish were as high as in the Baltic Sea fish. Dioxin-like PCBs contributed to the total dioxin-like toxicity of PCBs and PCDD/Fs by 49+/-12% in all the analysed samples.     

Brominated flame retardants — Ubiquitous environmental pollutants?

Biological samples from marine environments have been analyzed with a technique selectively sensitive for brominated organic compounds. All samples contained a number of such substances and some of them were characterized as polybrominated biphenyls (PBB) and diphenyl ethers (PBDE), respectively. The chromatographic pattern of these two groups agreed well with the corresponding patterns from two commercial flame retardants based on these types of substances. The samples analyzed so far (seal, guillemots and white-tailed sea eagle) were collected in the Baltic, the North Sea and the Arctic Ocean. The levels of PBB and PBDE were two to five times higher in samples from the Baltic than in samples from the other places, possibly indicating local sources. The presence of these compounds in samples from remote areas indicates a world-wide distribution and emphasizes the risk in the use of polyhalogenated hydrocarbons.     

Seasonal variations of hydroxylated and methoxylated brominated diphenyl ethers in blue mussels from the Baltic Sea

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) found at high levels in the Baltic biota are mainly natural products, but can also be formed through metabolism or abiotic oxidation of polybrominated diphenyl ethers (PBDEs). The formation of OH-PBDEs is of concern since there is growing evidence of phenolic toxicity. This study investigates seasonal variations in levels of OH-PBDEs and MeO-PBDEs, focusing on an exposed species, the blue mussel (Mytilus edulis), sampled in the Baltic Sea in May, June, August and October of 2008. Both the OH-PBDE and MeO-PBDE levels in the mussels showed seasonal variations from May to October, the highest concentration of each congener appearing in June. The seasonal variation was more marked for OH-PBDEs than in MeO-PBDEs, but all congeners showed the same trends, except 6-MeO-BDE47 and 2′-MeO-BDE68, which did not significantly decline in concentrations after June. Biotic or abiotic debromination is suggested as a possible reason for the rapid decrease in methoxylated penta- and hexa-BDE concentrations observed in blue mussels from June to August, while the tetraBDE concentrations were stable. In addition, 1,3,7/1,3,8-tribrominated dibenzo-p-dioxins showed the same seasonal variation. The seasonal variations indicates natural formation and are unlikely to be due to transformation of anthropogenic precursors. The levels of PBDEs were fairly constant over time and considerably lower than those of the OH-PBDEs and MeO-PBDEs. The timing of the peaks in concentrations suggests that filamentous macro-algae may be important sources of these compounds found in the blue mussels from this Baltic Sea location.     

Hydroxylated and methoxylated polybrominated diphenyl ethers and polybrominated dibenzo-p-dioxins in red alga and cyanobacteria living in the Baltic Sea

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are present in the ecosystem of the Baltic Sea. OH-PBDEs are known to be both natural products from marine environments and metabolites of the anthropogenic polybrominated diphenyl ethers (PBDEs), whereas, MeO-PBDEs appear to be solely natural in origin. Polybrominated dibenzo-p-dioxins (PBDDs) are by-products formed in connection with the combustion of brominated flame retardants (BFRs), but are also indicated as natural products in a red alga (Ceramium tenuicorne) and blue mussels living in the Baltic Sea. The aims of the present investigation were to quantify the OH-PBDEs and MeO-PBDEs present in C. tenuicorne; to verify the identities of PBDDs detected previously in this species of red alga and to investigate whether cyanobacteria living in this same region of the Baltic Sea contain OH-PBDEs, MeO-PBDEs and/or PBDDs. The red alga was confirmed to contain tribromodibenzo-p-dioxins (triBDDs), by accurate mass determination and additional PBDD congeners were also detected in this sample. This is the first time that PBDDs have been identified in a red alga. The SigmaOH-PBDEs and SigmaMeO-PBDEs concentrations, present in C. tenuicorne were 150 and 4.6 ng g(-1) dry weight, respectively. In the cyanobacteria 6 OH-PBDEs, 6 MeO-PBDEs and 4 PBDDs were detected by mass spectrometry (electron capture negative ionization (ECNI)). The PBDDs and OH-PBDEs and MeO-PBDEs detected in the red alga and cyanobacteria are most likely of natural origin.     

First study of congener group patterns and concentrations of short- and medium-chain chlorinated paraffins in fish from the North and Baltic Sea

This study presents the first investigation of concentrations and congener group patterns of short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in fish from the North and Baltic Sea. North Sea dab, cod and flounder were studied. High resolution gas chromatography (HRGC) coupled to low resolution mass spectrometry (LRMS) in the electron capture negative ionization mode (ECNI) was employed. Good linearity (R2>0.993, 7 measuring points) was achieved between 1 and 100 ng/g of CP mixtures for SCCPs and MCCPs. The limits of detection were 0.5-1 ng/microl of CP mixture for the major congener groups of SCCPs and MCCPs. A clean-up comprising fat extraction, adsorption chromatography on silicagel impregnated with concentrated sulphuric acid and adsorption chromatography on Florisil was employed to avoid interferences from other polychlorinated compounds. Recoveries of CPs in spiked samples ranged between 80% and 100%. Accuracy was controlled with spiked samples and deviated not more than 10% from the expected values. Quantification was performed with standards of an average chlorine content as close as possible to that of the samples (SCCPs: 59-62%, MCCPs: 53-58%). SCCP concentrations ranged between 19 and 286 ng/g liver wet weight (ww), MCCP concentrations were comparable with a range of 25-260 ng/gww. Congener group patterns were also determined and discussed. In samples from the Baltic Sea the SCCP congener pattern was similar to that of commercial SCCP mixtures or C13 congeners were most abundant. In samples from the North Sea a higher relative abundance of C10 congeners was observed.     

Levels and trends of brominated flame retardants in the Arctic

Polybrominated diphenyl ethers (PBDEs) containing two to seven bromines are ubiquitous in Arctic biotic and abiotic samples (from zooplankton to polar bears (Ursus maritimus) and humans; air, soil, sediments). The fully brominated decabromodiphenyl ether (BDE-209), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and polybrominated biphenyls (PBBs) are also present in biotic and abiotic samples. Spatial trends of PBDEs and HBCD in top predators are similar to those seen for polychlorinated biphenyls (PCBs) and indicate western Europe and eastern North America as source regions. Concentrations of tetra- to heptaBDEs have increased significantly in North American and Greenlandic Arctic biota and in Greenland freshwater sediments paralleling trends seen further south. For BDE-209, increasing concentrations in Greenlandic peregrine falcons (Falco peregrinus) and in dated lake sediment cores in the Canadian Arctic have been seen during the 1990s. BDE-47, -99, -100 and -153 are observed to biomagnify in Arctic food webs. summation operatorPBDE concentrations in Arctic samples are lower than in similar sample types from more southerly regions and are one or more orders of magnitude lower than summation operatorPCB concentrations except for some levels for air. Air and harbor sediment results for PBDEs indicate that there are local sources near highly populated areas within the Arctic. Findings of PBBs on moss and TBBPA on an air filter, and that both are found in biota at high trophic levels indicates that these compounds may also reach the Arctic by long-range atmospheric transport. Based on the evidence of their presence in the Arctic and indications that most if not all are undergoing long-range transport, these brominated flame retardants (BFRs) have characteristics that qualify them as POPs according to the Stockholm Convention.     

Lipid-soluble conjugates of hydroxylated polybrominated diphenyl ethers in blue mussels from the Baltic Sea

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) of proposed natural origin have been detected throughout the food web of the Baltic Sea. Some OH-PBDEs have been shown to disrupt oxidative phosphorylation and the thyroid hormone system in exposed organisms. This paper describes an investigation into the fate of OH-PBDEs in the Baltic Sea’s predominant specie, the blue mussel. The main focus was on the conjugation of OH-PBDEs with lipophilic moieties (e.g., fatty acids) and the potential role this transformation mechanism may have in heavily exposed mussels in nature. Analytical methods were developed to accurately determine the concentrations of these conjugates in blue mussels collected on different occasions during the summer in a coastal area of the Baltic proper. The measured concentrations of conjugated OH-PBDEs were compared to those of the unconjugated parent compounds, and it was found that in some cases, the levels of the conjugated derivatives can be equal or even higher than the levels of the unconjugated OH-PBDEs. This is, to our knowledge, the first study on lipid-soluble OH-PBDE conjugates, and the first study to investigate the occurrence of such conjugates of halogenated phenolic compounds in environmentally exposed mussels. The mussels were also found to contain hydrolysable water-soluble derivatives of OH-PBDEs (such as e.g., glucuronic acid and/or sulfate conjugates etc.). These were tentatively determined to be of lower concentration (by up to an order of magnitude) than that of the OH-PBDEs which were conjugated with lipophilic moieties.     

Polybrominated diphenyl ethers (PBDEs) in farmed and wild salmon marketed in the Northeastern United States

Recently, we reported on the analysis of polychlorinated biphenyls (PCBs) and chlorinated pesticides in farmed Atlantic salmon (Salmo salar) from Maine, eastern Canada, and Norway, and wild Alaskan Chinook salmon (Oncorhynchus tshawytscha). In this paper, we extend the analysis to polybrominated diphenyl ethers (PBDEs) in these samples. Total PBDE concentrations in the farmed salmon (0.4-1.4ng/g, wet weight, ww) were not significantly different from those in the wild Alaskan Chinook samples (0.4-1.2ng/g, ww), nor were significant differences found among regions. However, significant intra-regional variations in concentrations of total PBDEs and tetra-BDE 47 were observed in the salmon from the Canadian farms (p<0.01). Congener profiles were dominated by BDE-47, followed by the penta-BDEs 99 and 100. PBDE concentrations in the Canadian samples were lower than those reported two years earlier. Removal of skin resulted in no overall reduction in PBDE concentrations in our farmed salmon, and in some cases, PBDE concentrations were higher in skin-off samples. PBDEs were correlated with lipids only in the skinned samples, suggesting that there is greater accumulation and retention of PBDEs in muscle lipids than in skin-associated fat. In skin-on samples, modest correlations were observed between concentrations of PBDEs and PCBs (R(2)=0.47) and mono-ortho PCBs (R(2)=0.50), whereas PBDEs were not correlated with non-ortho PCBs.     

Brominated phenols,anisoles, and dioxins present in blue mussels from the Swedish coastline

Introduction  

Naturally occurring hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methoxylated counterparts (MeO-PBDEs), and polybrominated dibenzo-p-dioxins (PBDDs), together with their potential precursors polybrominated phenols (PBPs) and polybrominated anisoles (PBAs), were analyzed in blue mussels (Mytilus edulis) gathered along the east coast (bordering the Baltic Sea) and west coast of Sweden (bordering the North Sea). Brown algae (Dictyosiphon foenicolaceus) and cyanobacteria (Nodularia spumigena) from the Baltic Sea, considered to be among the primary producers of these compounds, were also analyzed for comparison.     

Contents and origin of polychlorinated diphenyl ethers (PCDE) in salmon from the Baltic Sea, Lake Saimaa and the Tenojoki river in Finland

The presence of 26 congeners of polychlorinated diphenyl ethers (PCDEs) was investigated in salmon from three locations in Finland. In addition to salmon, one chlorophenol wood preservative (Ky-5) and one fly ash sample were analyzed for PCDEs. Concentrations of PCDE congeners in salmon muscle measured by high resolution gas chromatography/low resolution mass spectrometry ranged from < 0.02 to 2.4 ng/g fresh weight. The major components of tetra- to octachlorinated PCDEs in salmon were one TeCDE (22′44′-), two PeCDEs (22′44′5- and 23′44′5-) and three HxCDEs (22′44′56′-, 22′44′55′- and 22′344′5-). The Baltic salmon caught from the Simojoki River had higher levels of PCDEs than the Atlantic salmon from the Tenojoki River or salmon from Lake Saimaa in South-Finland. Same PCDE congeners which were abundant in the wood preservative were also detected in salmon, whereas PCDE congeners in the fly ash were different from those in salmon or in Ky-5.     

Non-polar halogenated natural products bioaccumulated in marine samples. II. Brominated and mixed halogenated compounds

Several identified and potential natural brominated bioaccumulative compounds were studied in this work. 4,6-dibromo-2-(2('),4(')-dibromo)phenoxyanisole (BC-2) previously detected in Australian marine mammals and isolated from sponges, was synthesized. Two byproducts (a tetrabromo isomer and a tribromo congener) were investigated as well. The byproducts of the synthesis were not identified in the environmental samples investigated. Previously described natural brominated compounds (BC-1, BC-2, BC-3, BC-10, BC-11, MHC-1) and anthropogenic brominated diphenyl ethers (BDE-47, BDE-99, BDE-100, BDE-154) were detected in a sample of human milk. The sample was from a woman from the Faeroe Islands who frequently consumed fish as well as whale blubber and meat. The most abundant compound originated from the natural tetrabromo phenoxyanisole BC-3 which may have a 3:1 distribution of bromine on the two phenyl units. This sample also accumulated a dibromochloroanisole, as well as a previously unknown mixed halogenated compound (MHC-X) and an unknown, most likely aromatic brominated compound. Co-elutions on a DB-5 column were found for BDE-99 and BC-11 as well as BDE-154 and the unknown brominated compound. This suggests that quantification of these two compounds has to be carried out carefully.Two samples of lower trophic level, namely Baltic cod liver and Mexican mussel tissue, were investigated as well. The cod liver samples contained BDE congeners but also abundant signals for the natural 2,3,3('),4,4('),5,5(')-heptachloro-1(')-methyl-1,2(')-bipyrrole Q1 and tribromoanisole (TBA). The mussel sample contained Q1, TBA, another halogenated anisole, BC-1, BC-2, and BC-3, as well as additional, potential natural brominated compounds in the elution range of tribromophenoxyanisoles.     

Temporal and spatial trends of PCBs,DDTs, HCHs,and HCB in Swedish marine biota 1969–2012

In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring (Clupea harengus) and in guillemot (Uria aalge) egg, but also in cod (Gadus morhua), perch (Perca fluviatilis), eelpout (Zoarces viviparous), and blue mussel (Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70–90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 µg kg^?1 lipid weight and 5 µg kg^?1 wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms.     

Temporal trends in the bioaccumulation of trace metals in herring, sprat, and cod from the southern Baltic Sea in the 1994–2003 period

This study is based on raw data obtained from 1 225 samples of herring (Clupea harengus), sprat (Sprattus sprattus), and cod (Gadus morhua) collected in the 1994–2003 period from the Polish coastal zone of the Baltic Sea. This paper presents the results of investigations of the contents of Cu, Zn, Cd, Pb, Hg, and As in fish. The aim was to identify temporal trends in trace metal contamination and variations in the concentrations of Hg in the flesh of herring, sprat, and cod of different lengths. A positive correlation between fish length and Hg concentration was noted for cod, sprat, and herring. The temporal trend analyses of heavy metal concentrations in the fish in the 1994–2003 period indicated ten significant downward trends out of eighteen tests; these referred to concentrations of Cd, Hg, and Pb in all the species studied, and to As in sprat. Concentrations of Cu and Zn remained stable in all the species studied, as did As in herring and cod. No upward trends were detected in the concentration of trace metals in the fish studied. Smaller scale temporal variations in concentrations of some elements were also observed and were associated with natural events, such as increased river discharge resulting from floods. The most likely factors which contributed to the observed downward trends in heavy metals concentrations in fish could possibly stem from lesser quantities of Cd, Pb, and Hg being introduced to the Baltic Sea with the waters of rivers from Baltic countries, including Poland, and atmospheric depositions in the 1994–2003 period. Diminishing trends of concentrations of these elements in Baltic Sea waters are also evidence of this. These facts might indicate that advantageous changes are occurring in the concentrations of heavy metals in the southern Baltic environment.     

Trophic transfer of persistent organochlorine contaminants (OCs) within an Arctic marine food web from the southern Beaufort-Chukchi Seas

Stable isotope values (13C, 15N) and concentrations of persistent organochlorine contaminants (OCs) were determined to evaluate the near-shore marine trophic status of biota and biomagnification of OCs from the southern Beaufort-Chukchi Seas (1999-2000) near Barrow, AK. The biota examined included zooplankton (Calanus spp.), fish species such as arctic cod (Boreogadus saida), arctic char (Salvelinus alpinus), pink salmon (Oncorhynchus gorbuscha), and fourhorn sculpin (Myoxocephalus quadricornis), along with marine mammals, including bowhead whales (Balaena mysticetus), beluga whales (Delphinapterus leucas), ringed seals (Phoca hispida) and bearded seals (Erignathus barbatus). The isotopically derived trophic position of biota from the Beaufort-Chukchi Seas marine food web, avian fauna excluded, is similar to other coastal food webs in the Arctic. Concentrations of OCs in marine mammals were significantly greater than in fish and corresponded with determined trophic level. In general, OCs with the greatest food web magnification factors (FWMFs) were those either formed due to biotransformation (e.g. p,p'-DDE, oxychlordane) or considered recalcitrant (e.g. -HCH, 2,4,5-Cl substituted PCBs) in most biota, whereas concentrations of OCs that are considered to be readily eliminated (e.g. -HCH) did not correlate with trophic level. Differences in physical-chemical properties of OCs, feeding strategy and possible biotransformation were reflected in the variable biomagnification between fish and marine mammals. The FWMFs in the Beaufort-Chukchi Seas region were consistent with reported values in the Canadian Arctic and temperate food webs, but were statistically different than FWMFs from the Barents and White Seas, indicating that the spatial variability of OC contamination in top-level marine Arctic predators is attributed to differences in regional sources of contamination rather than trophic position.     

Anaerobic transformation of polybrominated biphenyls with the goal of identifying unknown hexabromobiphenyls in Baltic cod liver

Polybrominated biphenyls (PBBs) have been introduced as flame retardants in 1970. Despite decreasing application rates since the mid-1970s, PBB residues are still reported in the environment. Furthermore, environmental PBB residues often do not match the PBB pattern in technical products. To get insights into the structures of environmentally-relevant PBBs, the congener patterns of technical hexabromobiphenyl (THBB), octabromobiphenyl (TOBB), synthesized PBB 209 were compared to PBB residues in a cod liver sample from the Baltic Sea. The most relevant PBB congeners in Baltic cod liver were not present in the technical products and therefore most likely metabolites. For this reason, TOBB and HPLC-fractions obtained from this technical product were incubated with super-reduced cyanocobalamine. Reductive debromination was found to be the predominant transformation process. Bromine substituents in ortho-positions proved to be more recalcitrant, and several of the unknown PBBs were tri- and tetra-ortho substituted congeners. Furthermore, the key-PBBs determined in Baltic cod liver were formed during this process. The most important hexabromobiphenyl in Baltic cod liver was identified as PBB 155 by parallel synthesis. PBB 155 which was not detected in the technical PBB product analyzed was suggested as an indicator PBB congener suited to decide whether PBB residues originate from the previous use of THBB (low relative abundance of PBB 155) or TOBB/TDBB (high relative abundance of PBB 155). The latter scenario was found to be valid for the Baltic cod liver sample. Thus, PBBs in the Baltic Sea appeared to originate from partially-weathered residues of PBB 209.     

Organohalogen pollutants in herring from the northern Baltic Sea: concentrations, congener profiles and explanatory factors

Organohalogen contaminants were investigated in Baltic herring caught from three catchment areas in the Baltic Sea, off the coasts of Finland. Pools of both small and large herring were analysed for polychlorinated biphenyls (PCB), dibenzo-p-dioxins, dibenzofurans, naphthalenes, camphenes (toxaphene), polybrominated diphenyl ethers and the pesticide DDT and its metabolites. PCB concentrations per fresh weight in small herring were at the same level in all catchment areas, i.e. the Bothnian Bay, the Bothnian Sea and the Gulf of Finland, revealing no hot spots and reflecting most likely long term emissions and atmospheric deposition. Differences in the levels and/or congener profiles of other contaminants between catchment areas may be explained by point sources. Similar concentrations in small and large herring in the Gulf of Finland were possibly due to their common nutrition. In the other areas, differences between small and large herring most likely reflected their different food sources.     

Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: Levels, sources and fluxes

Surface sediments from remote lakes and coastal areas from Ny-Ålesund, Svalbard, Norwegian Arctic were analyzed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Relatively high levels of PAHs were encountered from several lakes from Ny-Ålesund, which were within the range of levels reported for European high mountain lakes and some urban/industrialized areas in the world, pointing to the role of remote Arctic lakes as potential reservoir of semi-volatile organic compounds. Specific patterns of PBDEs were observed, showing higher concentrations of lower brominated compounds such as BDE-7, 17 and 28. Estimated surface sediment fluxes of PAHs in Ny-Ålesund remote lakes were similar to those observed for some European high mountain lakes. The current PAH levels in sediments from three lakes exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies.     

The occurrence of polybrominated diphenyl ethers in river and coastal biota from Portugal

Throughout this work PBDEs level determination in biota was developed for the first time in Portugal. The data obtained was important to provide a global perspective of Portugal contamination by PBDEs and allows the comparison with studies made in other countries. Environmental levels of fourteen polybrominated diphenyl ethers (PBDEs) were analysed in a number of biota samples (Barbus sp. and Mytilus galloprovincialis) taken over a large geographic range covering five rivers and coastal areas of Portugal. Tetrabromodiphenyl ether (BDE 47) was found in almost all samples ranging from not detected (nd) to 30ngg(-1) dry weight (dw). BDE 47 concentration is correlated with mussels weight indicating the bioaccumulation of this compound. Pentabromodiphenyl ethers (BDE 99 and BDE 100) were detected in several samples, but in lower concentrations.