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

Compositional profiles, persistency and toxicity of polychlorinated naphthalene (PCN) congeners in edible cod liver products from 1972 to 2017

Edible cod liver products including cod liver oil and canned cod liver, sampled over the last five decades from the North Atlantic region, including the Baltic Sea were analysed for a set of persistent and toxicologically significant polychlorinated naphthalene (PCN) congeners with some of the highest relative potencies (dioxin-like toxicity) among PCNs. The targeted congeners showed a near-universality of occurrence in all samples apart from the most recent sample of cod liver oil which was assumed to be highly purified, as cod livers from the same period and location showed appreciable amounts of PCNs. The majority of dominant congeners in legacy technical PCN mixtures were absent or occurred in low concentrations, raising the possibility that congeners arising from combustion related sources may be acquiring a greater significance following the decline and elimination of PCN production. The apparent appreciation in the relative amounts of PCN#70 in the last three to four decades may provide support for this view. The PCN contribution to dioxin-like toxic equivalence (TEQ) that was estimated for these samples (range 1.2-15.9 pg TEQ g^-1) was significant in comparison to the EU regulated value of 1.75 pg TEQ g^-1 for dioxins in fish oils. Most of the TEQ was associated with PCNs 66/67, 64/68, 69 and 73. Although metabolic processes are likely to influence this distribution, the profile is a little different to that observed in the tissues of higher order animals where PCNs #66/67 and #73 may contribute approximately 90% to the summed TEQ.

Determination of newly synthesized dihydroxylated polybrominated diphenyl ethers in sea fish by gas chromatography-tandem mass spectrometry

Dihydroxylated polybrominated diphenyl ethers (diOH-PBDEs) can be natural products of marine organisms or the metabolites of PBDEs. The optimal determination method and concentration of diOH-PBDEs in seafood are unknown due to a lack of commercially available standards. In the present study, diOH-PBDEs were synthesized, and an efficient measurement method for OH-PBDEs and diOH-PBDEs in sea fish muscle samples, including extraction, clean-up and gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis, was established. Pressurized liquid extraction (PLE) followed by partitioning with a KOH solution and florisil cartridge clean-up proved to be a reliable and robust method for detecting all OH-PBDEs/diOH-PBDEs. GC-MS/MS with an electron ionization (EI) source analysis was a sensitive analytical instrument for OH-PBDEs/diOH-PBDEs. The recovery using this method ranged from 19% to 101%, 28%-88% and 42%-90% for 10 ng, 20 ng and 40 ng spiking levels, respectively. The equipment detection limits (EDLs) were in the range of 0.31-2.78 pg/μL, and the limits of detection (LOD) for the method were in the range of 5.07-38.74 pg/g wet weight. Concentrations of diOH-PBDEs in the marine fish muscle samples were in the range of 32.43-1528.63 pg/g wet weight. Similar compositions of OH-PBDEs/diOH-PBDEs were found within the same family of marine fish.

Indirect study of the effect of α-tocopherol and acetylsalicylic acid on the mineral composition of bone tissue in the offspring of female rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin: long-term observations

This paper discusses problems related to the influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the mineral composition of the calvaria in the offspring of female rats.

Emerging brominated flame retardants and dechlorane-related compounds in European eels (Anguilla anguilla) from Latvian lakes

Fifteen halogenated flame retardants (HFRs) including seven emerging brominated flame retardants (EBFRs) and eight dechlorane-related compounds (DRCs) were analyzed in eels (Anguilla anguilla) sampled from five Latvian lakes. Out of the seven EBFRs, hexabromocyclododecane (HBCD) and decabromodiphenyl ethane (DBDPE) were found in eels in quantifiable concentrations, up to 6.58 and 33.0 ng g^-1 lipid weight (l.w.), respectively. The mean total concentration of DRCs (∑_DRC) in the samples was 0.62 ng g^-1 l.w. and the geographical distribution of DRC contamination was nearly uniform among the selected lakes. Dechlorane 602 (Dec 602) was the predominant component, whereas the composition of mixture containing syn- and anti-Dechlorane Plus (DP) stereoisomers showed a pronounced enrichment of the anti-DP isomer and was close to the composition of OxyChem^® DP commercial product. The determined concentrations of HFRs were lower than in other studies of aquatic biota from Europe and Asia, and the obtained results reflect the acceptable environmental status of Latvian lakes with regard to the total content of HBCD (∑_HBCD), considering the environmental quality standards (EQS) stated in the Directive 2013/39/EU. The highest ∑_HBCD levels were observed in eels from lakes corresponding to the industrialization of those areas, while the results of principal component analysis (PCA) showed that the concentration of HBCD depended on the particular sampling lake, reflecting non-uniform contamination of the Latvian environment with this EBFR.

Temporal trends of PBDD/Fs, PCDD/Fs, PBDEs and PCBs in ringed seals from the Baltic Sea (Pusa hispida botnica) between 1974 and 2015

Temporal trends in exposure to persistent organic pollutants (POPs) were assessed in 22 pooled samples gathered from 69 individuals of Baltic ringed seal (Pusa hispida botnica) from 1974 to 2015. Samples were analysed for polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). No previous study has reported on the occurrence of PBDD/Fs in marine mammals in the Baltic Sea. Concentrations of pollutants in Baltic ringed seal, a marine mammal and top predator, can be used as an indicator of pollutants concentrations in the Baltic region. Visual inspection of data did not show any temporal trends for PBDD/Fs, while the PCDD/Fs and PCBs showed decreasing concentrations between 1974 and 2015. PBDEs increased until the end of the 1990s and then decreased until the end of the period. ∑PBDD/Fs ranged from 0.5-52.3pg/g lipid weight (l.w.) (0.08-4.8pgTEQ/g l.w.), with 1,2,3,4,6,7,8-HpBDF contributing on average 61% to ∑PBDD/Fs. ∑PCDD/Fs ranged from 103 to 1480pg/g l.w. (39-784pgTEQ/g l.w.), with 1,2,3,6,7,8-HxCDD, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF showing the highest average concentrations. PBDD/F toxic equivalents (TEQ) contributed on average 1.1% to the total (PBDD/F+PCDD/F) TEQ. The ∑PBDEs concentration range was 18.7-503ng/g l.w., with BDE #47 the predominant congener. The concentration range for ∑PCBs was 2.8-40.1μg/g l.w., with #138 and #153 the most abundant congeners. Visual inspection of the data showed decreasing concentrations for all compound groups except PBDD/Fs. A slight increase in the PBDD/Fs concentrations was observed from 2004 onwards. This observation needs to be investigated further.

Occurrence of polybrominated dibenzo-p-dioxins, dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) in pilot whales (Globicephala melas) caught around the Faroe Islands

Blubber from Faroese pilot whales (Globicephala melas) was analysed for brominated dioxins PBDD/Fs, with a subset also analysed for chlorinated dioxins, PCDD/Fs. The studied individuals were restricted to juvenile male whales sampled in the Faroe Islands during the period 1997-2013. Among the PBDD/Fs, the furans were predominant, although the relative abundance of various congeners differed between samples. Furans accounted for, on average, 79% of the ∑PBDD/Fs in the samples, with 1,2,3,4,6,7,8-HpBDF the most abundant congener, found in half of the analysed pilot whales. The concentration range for ∑PBDD/Fs among the samples was 0.080-71 pg/g l.w. (lipid weight), and the sum of toxic equivalents ranged from 0.0039 to 4.7 pg TEQ/g l.w. No relationship was found between PBDD/Fs and PCDD/Fs. In addition, 20 pilot whale samples from the period 2010-2013 were analysed for PBDEs. Several PBDE congeners were found in all of the sampled pilot whales, and at noticeably higher levels than PBDD/Fs and PCDD/Fs. The ∑PBDEs ranged from 140 to 1900 ng/g l.w., with BDE #47 the most abundant congener detected in the samples. Results from the present study were then compared with data from previous studies on pilot wales to investigate temporal trends between 1986 and 2013. The comparison indicated that PBDE concentrations in juvenile males have decreased from 1996 to the latest observations in 2013. No relationship between the concentration levels of PBDD/Fs and PBDEs in the sampled pilot whales could be identified, which indicates possible differences in the metabolism of, or exposure to, PBDEs and PBDD/Fs.

The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards

A major challenge for society is to manage the risks posed by the many chemicals continuously emitted to the environment. All chemicals in production and use cannot be monitored and science-based strategies for prioritization are essential. In this study we review available data to investigate which substances are included in environmental monitoring programs and published research studies reporting analyses of chemicals in Baltic Sea fish between 2000 and 2012. Our aim is to contribute to the discussion of priority settings in environmental chemical monitoring and research, which is closely linked to chemical management. In total, 105 different substances or substance groups were analyzed in Baltic Sea fish. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were the most studied substances or substance groups. The majority, 87%, of all analyses comprised 20% of the substances or substance groups, whereas 46 substance groups (44%) were analyzed only once. Almost three quarters of all analyses regarded a POP-substance (persistent organic pollutant). These results demonstrate that the majority of analyses on environmental contaminants in Baltic Sea fish concern a small number of already regulated chemicals. Legacy pollutants such as POPs pose a high risk to the Baltic Sea due to their hazardous properties. Yet, there may be a risk that prioritizations for chemical analyses are biased based on the knowns of the past. Such biases may lead to society failing in identifying risks posed by yet unknown hazardous chemicals. Alternative and complementary ways to identify priority chemicals are needed. More transparent communication between risk assessments performed as part of the risk assessment process within REACH and monitoring programs, and information on chemicals contained in consumer articles, would offer ways to identify chemicals for environmental analysis.

Persistent organic pollutants in Baltic herring (Clupea harengus)-an aspect of gender

Persistent organic pollutants (POPs) are monitored regularly in water, sediment, and biota in the Baltic Sea. Lipophilic substances are measured in remarkable concentrations especially in the fatty parts of fish, such as herring (Clupea harengus). However, less lipophilic POPs, e.g. perfluorinated compounds (PFCs), can also be detected. For the first time to our knowledge, this study provides a broad range of contaminant concentrations simultaneously measured in filet, liver, and gonads of both sexes of Baltic herring. We analysed organochlorines, polybrominated diphenyl ethers (PBDEs), and PFCs in mature autumn-spawning individuals and found distinct organ pollutant pattern for all POPs in both sexes. POP concentrations found in the gonads of both sexes indicate that not only females but also males tend to reduce contaminants via reproduction. However, sex-dependent differences could be identified for hexachlorobenzene, PBDEs, and were most remarkable for PFCs. This transfer of contaminants to the gonads in both male and female herring is being underestimated, as it may directly affect the general reproduction success as well as the healthy development of the next generation. Hence, the accumulation of contaminants in the gonads should be considered one possible threat to a healthy wildlife as its achievement is stated by the Baltic Sea Action Plan. Inclusion of a periodic monitoring of POP concentrations in gonads of fish may be an important bioeffect measure to assess the environmental status of biota in the Baltic Sea.

Biomonitoring of selected persistent organic pollutants (PCDD/Fs, PCBs and PBDEs) in Finnish and Russian terrestrial and aquatic animal species

BACKGROUND

The Finnish and Russian animal species (semi-domesticated reindeer, Finnish wild moose, Baltic grey seal and Baltic herring) samples were biomonitored in terrestrial and aquatic environments for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs).

RESULTS

Grey seal (Halichoerus grypus) was clearly the most contaminated species. The mean PBDE concentration in grey seal was 115 ng/g fat, and the highest WHO-PCDD/F-PCB-TEQ (toxic equivalent set by WHO) was 327 pg/g fat. In Finnish, reindeer WHO-PCDD/F-TEQ varied from 0.92 pg/g fat in muscle to 90.8 pg/g fat in liver. WHO-PCDD/F-TEQ in moose liver samples was in the range of 0.7-4.26 pg/g fat, and WHO-PCB-TEQ in the range of 0.42-3.34 pg/g fat. Overall moose had clearly lower PCDD/F and DL-PCB concentrations in their liver than reindeer.

CONCLUSIONS

Terrestrial animals generally had low POP concentrations, but in reindeer liver dioxin levels were quite high. All Finnish and Russian reindeer liver samples exceeded the EU maximum level [8] for PCDD/Fs (10 pg/g fat), which is currently set for bovine animals.

Anthropogenic and naturally produced brominated substances in Baltic herring (Clupea harengus membras) from two sites in the Baltic Sea

In the eutrophicated Baltic Sea, several naturally produced hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been found in marine biota. OH-PBDEs are toxic to adult and developing zebrafish and shown to be potent disruptors of oxidative phosphorylation (OXPHOS). Disturbed OXPHOS can result in altered energy metabolism and weight loss. In herring, the concentration of OH-PBDEs (i.e. 2'-OH-BDE68 and 6-OH-BDE47) has increased during the period 1980-2010 in the Baltic Proper. Over the same time period, the condition and fat content in Baltic herring have decreased. Given the toxicity and increasing trends of OH-PBDEs in Baltic herring it is important to further assess the exposure to OH-PBDEs in Baltic herring. In this study, the concentrations of OH-PBDEs and related brominated substances i.e. polybrominated phenols (PBPs), polybrominated anisoles (PBAs), methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and polybrominated diphenyl ethers (PBDEs) were measured in herring sampled in the northern Baltic Proper (Askö, n = 12) and the southern Bothnian Sea (Ängskärsklubb, n = 12). The geometric mean (GM) concentrations (ng/g l.w.) at Askö and Ängskärsklubb were; Σ2PBPs: 4.3 and 9.6, Σ(2)PBAs: 34 and 20, Σ(6)OH-PBDEs: 9.4 and 10, Σ(7)MeO-PBDEs: 42 and 150, Σ(6)PBDEs: 54 and 27, respectively. 6-OH-BDE47 dominated the OH-PBDE profile and comprised 87% (Askö) and 91% (Ängskärsklubb) of the ΣOH-PBDEs. At Ängskärsklubb the mean concentration of ΣMeO-PBDEs (150 ng/g l.w.) was 15 times higher than ΣOH-PBDEs. As other fish species are known to metabolically transform MeO-PBDEs to OH-PBDEs, high levels of MeO-PBDEs can be of concern as a precursor for more toxic OH-PBDEs in herring and their roe.

PAHs and PCBs accumulated by SPMD-based virtual organisms and feral fish in Three Gorges Reservoir, China

Polycyclic aromatic hydrocarbon (PAHs) and polychlorinated biphenyls (PCBs) accumulated by semipermeable membrane device (SPMD)-based virtual organisms (VOs) and local feral fish were studied in Three Gorges Reservoir (TGR), China. VOs were deployed at seven sites in TGR for two periods in 2009 and 5 species of fish with different living habitats and feeding habits collected in the same periods from two counties in TGR. The concentration and profile of PAHs and PCBs in fish were quite different from those in VOs. Most high-molecular-weight-PAHs were detected in VOs, while they were undetected in fish. Most PCBs were undetected in VOs, while most of them were detected in fish. Low-molecular-weight-PAHs were predominant contaminants of PAHs and non-dioxin-like-PCBs were the main PCBs in fish. The levels of PAHs and PCBs in the few fish samples were low and were not of concern based on chemical contaminant limits of non-carcinogenic effect.

PCDD and PCDF exposures among fishing community through intake of fish and shellfish from the Straits of Malacca

Background

Exposure to PCDD/PCDF (dioxin and furan) through consumption of fish and shellfish is closely related to the occurrence of skin diseases, such as chloracne and hyperpigmentation. This study aimed to determine the exposure of PCDD/PCDF and its congeners in fish and shellfish obtained from different regions of the Straits of Malacca among the fishing community.

Methods

The risk of fish and shellfish consumption and exposure to PCDD/PCDF among fishermen living in coastal areas of the Straits were evaluated based on a cross-sectional study involving face to face interviews, blood pressure and anthropometric measurements, and administration of food frequency questionnaires (FFQ). Skin examination was done by a dermatologist after the interview session. Determination of 17 congeners of PCDD/PCDF in 48 composite samples of fish and shellfish was performed based on HRGC/HRMS analysis.

Results

The total PCDD/PCDF in the seafood samples ranged from 0.12 to 1.24 pg WHO-TEQ/g fresh weight (4.6-21.8 pg WHO-TEQ/g fat). No significant difference found for the concentrations of PCDD/PCDF between the same types of seafood samples obtained from the three different regions. The concentrations of the most potent congener, 2,3,7,8-TCDD in the seafood samples ranged from 0.01 to 0.11 pg WHO-TEQ/g FW (1.9 pg WHO-TEQ/g fat). A positive moderate correlation was found between the fat contents and concentrations of PCDD/PCDF determined in the seafood samples. The total PCDD/PCDF in all seafood samples were below the 1 pg WHO-TEQ/g fresh weight, with the exception of grey eel-catfish. The respondents had consumed fish and shellfish with the amounts ranging between 2.02 g and 44.06 g per person per day. The total PCDD/PCDF exposures through consumption of fish and shellfish among the respondents were between 0.01 and 0.16 pg WHO-TEQ/kg BW/day. With regard to the two PCDD/PCDF-related skin diseases, no chloracne case was found among the respondents, but 2.2 % of the respondents were diagnosed to have hyperpigmentation.

Conclusion

Intake of a moderate amount of fish and shellfish from the area is safe and does not pose a risk for skin diseases. An over-consumption of seafood from the potentially polluted area of the Straits should be monitored in future.

Brominated flame retardants and seafood safety: a review

Brominated flame retardants (BFRs), frequently applied to industrial and household products to make them less flammable, are highly persistent in the environment and cause multi-organ toxicity in human and wildlife. Based on the review of BFRs presence in seafood published from 2004 to 2014, it is clear that such pollutants are not ideally controlled as the surveys are too restricted, legislation inexistent for some classes, the analytical methodologies diversified, and several factors as food processing and eating habits are generally overlooked. Indeed, while a seafood rich diet presents plenty of nutritional benefits, it can also represent a potential source of these environmental contaminants. Since recent studies have shown that dietary intake constitutes a main route of human exposure to BFRs, it is of major importance to review and enhance these features, since seafood constitutes a chief pathway for human exposure and biomagnification of priority environmental contaminants. In particular, more objective studies focused on the variability factors behind contamination levels, and subsequent human exposure, are necessary to support the necessity for more restricted legislation worldwide.

Time trends and congener profiles of PCDD/Fs, PCBs, and PBDEs in Baltic herring off the coast of Finland during 1978-2009

In Finland, consumption of Baltic fatty fish may lead to high exposure to persistent organic pollutants (POPs), which might have hazardous health effects. Monitoring of POPs in Baltic fish enables the health authorities to keep dietary advice on fish consumption up to date. In this study, which is a compilation of analytical data from earlier studies, time trends and congener profiles of polychlorinated dioxins and furans (PCDD/Fs) and biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Baltic herring are reported. Altogether 344 samples of Baltic herring from 1978-2009 were collected across the Finnish coast of the Baltic Sea. The chemical analysis was performed in an accredited testing laboratory with high resolution gas chromatography mass spectrometry. During the 31-year period, PCDD/F and PCB concentrations decreased on approximately 80%, from approximately 20 to 5 pg/g fw, expressed as WHO2005 TEQ. The PBDE concentrations experienced a 4-10 fold increase during late 1980s-early 1990s, and declined to 1978s levels of approximately 2 ng/g fw by 2009. The current concentrations of PCDD/Fs, PCBs and PBDEs in Baltic herring are relatively low, and mostly below EU maximum accepted levels, and are expected to continue decreasing. In the future, it may be possible to re-evaluate the consumption restrictions for this specific Baltic fatty fish.

PCDD/Fs, PCBs and PBDEs in zooplankton in the Baltic Sea - spatial and temporal shifts in the congener-specific concentrations

In the marine food-webs, zooplankton is a key element in the transfer of persistent organic pollutants to higher trophic levels. We determined the congener-specific concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in offshore zooplankton (size from 0.2 to 20mm) collected in 2001, 2002 and 2010 in the northern and central Baltic Sea. Of the PCDD/Fs, the concentrations of 2378-TCDF were from 18 to 47 and of 23478-PeCDF from 7.9 to 29 pg g(-1)fat and showed little temporal differences. However, 1234678-HpCDF and OCDF were abundant in 2001-2002 especially in the eastern Gulf of Finland (average concentrations 50 and 89 pg g(-1)fat, respectively). In 2010 the concentrations of these two congeners were lower, 29 and 30 pg g(-1)fat, respectively, but still substantially higher than in the other surveyed areas. The principal components analysis (PCA) supported that area-specific patterns in pollution strongly contributed to the congener profiles particularly in surface sediment and in sediment trap material, but even in zooplankton. The concentrations of the PCBs were highest in the Gulf of Finland and in the Bothnian Bay. The concentrations of most PCBs were somewhat lower in 2010 than in 2001-2002. Of the dioxin-like PCBs, the concentrations of PCB-77 were highest (271-572 pg g(-1)fat) but PCB-126 (32-113 pg g(-1)fat) contributed from 85% to 91% of the total toxicity of PCBs due to its higher toxic potency. Of the PBDEs, the BDE47 and BDE99 were the most abundant (concentrations from 1.2 to 4.6 and from 0.4 to 3.3 ng g(-1) fat, respectively). The concentrations of most PBDEs were lower in 2010 than in 2001/2002 except in the eastern Gulf of Finland.

Dioxin-like polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans in seafood samples from Malaysia: estimated human intake and associated risks

A total of 127 and 177 seafood samples from Malaysia were analyzed for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs), respectively. The World Health Organization-toxic-equivalency quotients (WHO-TEQ) of PCDD/Fs varied from 0.13 to 1.03 pg TEQ g(-1), whereas dl-PCBs ranged from 0.33 to 1.32 pg TEQ g(-1). Based on food-consumption data from the global environment monitoring system-food contamination monitoring and assessment programme, calculated dietary exposures to PCDD/Fs and dl-PCBs from seafood for the general population in Malaysia were 0.042 and 0.098 pg TEQ kg(-1) body weight day(-1), respectively. These estimations were quite different from the values calculated using the Malaysian food-consumption statistics (average of 0.313 and 0.676 pg TEQ kg(-1) body weight day(-1) for PCDD/Fs and PCBs, respectively). However, both of the dietary exposure estimations were lower than the tolerable daily intake recommended by WHO. Thus, it is suggested that seafood from Malaysia does not pose a notable risk to the health of the average consumer.

The toxicological effects of halogenated naphthalenes: a review of aryl hydrocarbon receptor-mediated (dioxin-like) relative potency factors

There is no doubt that chloronaphthalenes (PCNs) and their brominated counterparts (PBNs) are dioxin-like compounds, but there is less evidence for mixed bromo/chloronaphthalenes (PXNs). In this article we review information relating to the dioxin-like potency of PCNs and PBNs obtained in vivo, in vitro, and in silico. The aim was to help and improve the quality of data when assessing the contribution of these compounds in the risk analysis of dioxin-like contaminants in foods and other sample types. In vivo and in vitro studies have demonstrated that PCN/PBN congeners are inducers of aryl hydrocarbon hydroxylase, ethoxyresorufin O-deethylase, and luciferase enzymes that are features specifically indicative of planar diaromatic halogenated hydrocarbons such as dioxin and dioxin-like compounds. PCNs in the environment are of multisource origin. The limited data on PBNs in the environment suggest that these also appear to originate from different sources. The toxicological data on these compounds is even scarcer, most of it directed toward explaining the exposure risk from accidental contamination of feed with the commercial PBN containing product, Firemaster BP-6. The occurrence of PBNs and PXNs is possible as ultra-trace environmental and food-chain contaminants produced at least from combustion processes at unknown concentrations. Available toxicological and environmental data enable a focus on PCNs as dioxin analogues to an extent that specific local or regional environmental influences could result in a risk to human health. There is the possibility that they may act synergistically with the better-known classic dioxin and other dioxin-like compounds. PBNs and PXNs are much less studied than the dioxins, but are known to be products of anthropogenic processes that contaminate the environment. A continuously increasing use of bromine for manufacture of brominated flame retardants over the past three decades is anticipated as a stream of "brominated" wastes, that when degraded (combusted), will release PBNs and PXNs. This calls for advanced analytical methods and greater interest toxicologically to understand and control pollution and exposure by PBNs and PXNs. Particular congeners of bromonaphthalene in single studies were found to be much more toxic than their chlorinated counterparts. In addition, brominated/chlorinated naphthalenes also seem to be more potent toxicants than PCNs. About 20% of PCN congeners exhibit a dioxin-like toxicity with relative potencies varying between around 0.003 and 0.000001, but additional and more rigorous data are needed to confirm these figures. Recent food surveys have estimated a small but relevant human exposure to these compounds in foods, giving an additional source of dioxin-like toxicity to those compounds already covered by the World Health Organization-Toxic Equivalency Factors (TEFs) scheme. Given the additivity of response postulated for other dioxin-like compounds, it would seem unwise to ignore this additional contribution. Few data available showed that PBN congeners also exhibit a dioxin-like toxicity and are even more potent than PCN congeners, but the relative potency values were not derived for them until now. There are no toxicological data available for PXNs.

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

The contamination profiles of polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), diphenyl ethers (PBDEs), and mixed monobromo/chloro dibenzo-p-dioxins (PXDDs) and dibenzofurans (PXDFs) were determined in the tissue of Baltic wild salmon and compared with those of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs). Out of the analyzed PXDD/DFs, only the 3-B-2,7,8-triCDF was detected (in the concentration range of 0.039-0.075 pg g(-1) fresh weight (f.w.)). The toxic equivalents (TEQs) for analyzed PBDD/DFs (0.074-0.142 pg TEQ g(-1) f.w.) were found to contribute on average 2.1% to the total PCDD/DF-PBDD/DF-TEQ. The total concentrations of 27 PBDE congeners were in the range of 1.3-5.6 ng g(-1) f.w., with an average of 3.3 ng g(-1) f.w. The levels of PCDD/DFs and PCBs were found to be in the range of 4.53-14.6 pg WHO(2005)-PCDD/DF-PCB-TEQ g(-1) f.w., and concentrations of these compounds in most of the analyzed samples were above the maximum levels specified in Commission Regulation (EU) No. 1259/2011. Good correlation was observed between WHO(2005)-PCDD/DF-TEQ and WHO(2005)-PCB-TEQ (r(2) = 0.98), and these parameters were well correlated with the total sum of PBDE concentrations (r(2) = 0.91 and r(2) = 0.94, respectively). The results suggest that the consumption of Baltic wild salmon has no crucial impact on the average POP intake for typical Latvians.

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho-PCBs in eggs of white-tailed sea eagles collected along the Swedish coast in the Baltic Sea

Concentrations of polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and dioxin-like non-ortho-PCBs were measured in white-tailed sea eagle (WTSE) eagle eggs collected along the Swedish coast of the Baltic Sea during the period 1992-2004. The eggs represent two different subpopulations with significantly different nestling brood sizes; the Baltic Proper (BP) with an approximately normal nestling brood size (1.62), and the south Bothnian Sea (sBS) with reduced nestling brood size (1.22) combined with a significantly higher rate of dead eggs. The aim was to investigate if this difference in reproductive outcome was linked to differences in exposure to dioxin-like compounds. Three eggs collected in Greenland in 2000 were included in the study to provide a reference sea eagle population outside of the Baltic Sea region. The concentrations of ∑PCDD, ∑PCDF and ∑non-ortho-PCB in the two subpopulations from the Baltic Sea (BS) region ranged from 0.41-4.1, 1.2-5.3 and 180-970 ng/g lipids, respectively, while in the Greenland population the ranges were 0.11-0.16, 0.22-0.33 and 57-83 ng/g lipid, respectively. 2,3,4,7,8-PCDF was the predominant congener in all areas and accounted for on average 31-49% of the total ∑PCDD/F concentrations. The total toxic equivalents (TEQ) in sBS WTSEs were higher (approximately 39 ng TEQ/g lipid) than reported in eggs for many other birds, and the major contributors to the TEQ in the Baltic Sea were the non-ortho-PCBs. A principal component analysis (PCA) showed a difference in congener pattern between the two Baltic regions that was statistically significant (Hotelling's T(2) test). We found no significant differences in the total TEQ between the two populations (sBS-BP) and thus no evidence was found linking the reproductive impairment in WTSE in sBS to the concentrations of PCDD/Fs or non-ortho-PCBs in the eggs.

Associations between congenital cryptorchidism in newborn boys and levels of dioxins and PCBs in placenta

In animal studies, exposure to dioxins has been associated with disrupted development of the male reproductive system, including testicular maldescent. Some polychlorinated biphenyls (PCBs) have also dioxin-like effects. In addition, one previous case-control study has reported an association between congenital cryptorchidism and colostrum PCB levels. We performed a case-control study to evaluate whether congenital cryptorchidism in boys was associated with increased levels of dioxins or PCBs in placenta reflecting foetal exposure. In addition, associations between placenta levels of these chemicals and reproductive hormone levels in boys at 3 months were studied. Placentas were collected in a Danish-Finnish joint prospective cohort study on cryptorchidism (1997-2001). The boys were examined for cryptorchidism at birth and at 3 months. Altogether, 280 placentas [112 Finnish (56 cases, 56 controls) and 168 Danish (39 cases, 129 controls)] were analysed for 17 toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 37 PCBs (including 12 dioxin-like PCBs). Infant serum samples taken at 3 months were analysed for reproductive hormones. No significant differences between cases and controls were observed in either country in dioxin WHO-TEq levels (median 9.78 vs. 8.47 pg/g fat, respectively, in Finland, and 11.75 vs. 10.88 pg/g fat in Denmark) or PCB WHO-TEq levels (median 2.12 vs. 2.15 pg/g fat in Finland, 2.34 vs. 2.10 pg/g fat in Denmark) or total-TEq levels (median 11.66 vs. 10.58 pg/g fat in Finland, 13.94 vs. 13.00 pg/g fat in Denmark). Placenta WHO-TEq levels of dioxins were not associated with infant reproductive hormone levels at 3 months. In Finland, PCB WHO-TEq levels in placenta associated positively with infant LH levels. WHO-TEq levels of dioxins and PCBs and total-TEq levels were higher in Danish than Finnish samples. In conclusion, no association between placenta levels of dioxins or PCBs and congenital cryptorchidism was found. Significant country differences in chemical levels were observed.

Occurrence of PCDD/F, PCB, PBDE, PFAS, and organotin compounds in fish meal, fish oil and fish feed

We analysed polychlorinated dibenzo-p-dioxins and furans (PCDD/F, dioxins), and polychlorinated biphenyls (PCB) in 13 fish meal, five fish oil, and seven fish feed samples. Polybrominated diphenyl ethers (PBDE), organotin compounds (OTC), and perfluoroalkylated substances (PFAS) were analysed in ten fish meal, two fish oil, and two fish feed samples. All measured TEQ concentrations of PCDD/F and PCB were below the maximum levels set by Directive 2002/32/EC. There was no correlation between concentrations of WHOPCDD/F-TEQ and indicator PCB in our samples. The most common congeners among PBDEs were BDE-47 and BDE-100. BDE-209 was present in five fish meals of the ten analysed. Tributyltin (TBT) was the predominant congener in all samples except in three fish meals, where monobutyltin (MBT) was the major congener. Perfluorooctane sulphonate (PFOS) was the predominant congener in six fish meals of the ten analysed. There was large variation in concentrations and congener distributions of the studied compounds between our samples. Our results underline a need to pay special attention to the origin and purity of feed raw material of marine origin.

Seasonal variation in the levels of organohalogen compounds in herring (Clupea harengus) from the Norwegian Sea

The Norwegian spring spawning (NSS) herring is an ecologically important fish stock in the Norwegian Sea, and with a catch volume exceeding one million tons a year it is also economically important and a valuable food source. In order to provide a baseline of the levels of contaminants in this fish stock, the levels of organohalogen compounds were determined in 800 individual herring sampled at 29 positions in the Norwegian Sea and off the coast of Norway. Due to seasonal migration, the herring were sampled where they were located during the different seasons. Concentrations of dioxins and dioxin-like PCBs, non-dioxin-like PCBs (PCB(7)) and PBDEs were determined in fillet samples of individual herring, and found to be relatively low, with means (min-max) of 0.77 (0.24-3.5) ng TEQ kg(-1) wet weight (ww), 5.0 (1.4-24) μg kg(-1) ww and 0.47 (0.091-3.1) μg kg(-1) ww, respectively. The concentrations varied throughout the year due to the feeding- and spawning cycle: Starved, pre-spawning herring caught off the Norwegian coast in January-February had the highest levels and those caught in the Norwegian Sea in April-June, after further starvation and spawning, had the lowest levels. These results show that the concentrations of organohalogen compounds in NSS herring are relatively low and closely tied to their physiological condition, and that in the future regular monitoring of NSS herring should be made in the spawning areas off the Norwegian coast in late winter.

PCDD/F, PCB, PBDE, HBCD and chlorinated pesticides in a Swedish market basket from 2005--levels and dietary intake estimations

Based on consumption data statistics, food items from four regions in Sweden were sampled in a so-called market basket study. Food items from five food groups, i.e. fish, meat, dairy products, eggs and fat/oils, were analyzed for persistent organic pollutants (POPs) followed by per capita intake calculations. The highest levels of PCDD/F, PCB, PBDE, HBCD and chlorinated pesticides were found in the fish/fish products. The estimated market basket per capita intake of PCDD/F and dl-PCB was 0.7pg WHO-TEQ kg bw(-1) d(-1) (TEFs from 1998). The intake of ∑PCB was estimated to 4.9 ng kg bw(-1) d(-1) and fish was found to be the major contributor with 64%. The intake of ∑PBDE was found to be 0.7 ng kg bw(-1) d(-1). Fish (38%) and dairy products (31%) were the largest contributors to the total PBDE intake. The intake of HBCD was estimated to 0.14 ng kg bw(-1) d(-1). HBCD mainly came from fish (65%), but also dairy products (24%) and meat (10%) contributed. Also regarding the chlorinated pesticides, fish was found to be the major contributor, with 51% of the ∑DDT coming from fish. The intake of ∑DDT, ∑HCH and HCB was 4.0, 1.0 and 1.1 ng kg bw(-1) d(-1), respectively. Most of the ∑HCH and HCB originate from dairy products (43% and 55%, respectively). This study shows that the levels, and intake, of different POPs from food of animal origin in the market basket of 2005 seem to have decreased since the market basket study in 1999.

Application of mass spectrometry in the analysis of polybrominated diphenyl ethers

This review summarized the applications of mass spectrometric techniques for the analysis of the important flame retardants polybrominated diphenyl ethers (PBDEs) to understand the environmental sources, fate and toxicity of PBDEs that were briefly discussed to give a general idea for the need of analytical methodologies. Specific performance of various mass spectrometers hyphenated with, for example, gas chromatograph, liquid chromatograph, and inductively coupled plasma (GC/MS, LC/MS, and ICP/MS, respectively) for the analysis of PBDEs was compared with an objective to present the information on the evolution of MS techniques for determining PBDEs in environmental and human samples. GC/electron capture negative ionization quadrupole MS (GC/NCI qMS), GC/high resolution MS (GC/HRMS) and GC ion trap MS (GC/ITMS) are most commonly used MS techniques for the determination of PBDEs. New analytical technologies such as fast tandem GC/MS and LC/MS become available to improve analyses of higher PBDEs. The development and application of the tandem MS techniques have helped to understand environmental fate and transformations of PBDEs of which abiotic and biotic degradation of decaBDE is thought to be one major source of Br(1-9)BDEs present in the environment in addition to direct loading from commercial mixtures. MS-based proteomics will offer an insight into the molecular mechanisms of toxicity and potential developmental and neurotoxicity of PBDEs.

Polychlorinated naphthalenes in polar environments--a review

Polychlorinated naphthalenes (PCNs) consist of naphthalene substituted with 1-8 chlorines, yielding 75 possible congeners. They were formerly used in industry, occur at trace levels in commercial PCB mixtures, and have current sources in combustion processes. PCNs are widespread in arctic air with higher levels in the European Arctic. Concentrations were higher during the cold months in arctic Canada and Russia, but no seasonality was noted in subarctic Canada and Greenland. "Marker" congeners indicative of combustion were evident at some sites. Total toxic equivalents (TEQ) in air due to PCNs+dioxin-like PCBs were dominated by PCNs in arctic Canada and Russia, but not in subarctic Canada. Deposition of PCNs in snow was measured in northern Norway and Svalbard. Surveys of PCNs in the lower food web are limited to the northern Baltic Sea and lakes/rivers of northern Scandinavia. PCNs showed little or no biomagnification in lower food webs of the northern Baltic and discrimination among congeners suggested preferential metabolism. There are no reports of PCNs in fish and invertebrates from the Arctic Ocean, and only one from Antarctica. Total PCNs in marine mammals followed the order: harbour seal~pilot whale>or=polarbear>beluga>ringed seal~Weddell seal. Total PCNs in seabirds varied over 100-fold, with higher concentrations in glaucous gull eggs and plasma from Bear Island, and livers of northern fulmar from the eastern Canadian Arctic. Lower concentrations occurred in eggs of glaucous gull from Svalbard and black-backed gull from the Faroe Islands. PCNs accounted for <1% of total TEQ in ringed seal, Weddell seal, seabirds and polar bear, but up to 6-15% in beluga and pilot whale. TEQ due to PCNs were generally low in harbour seal, but up to 9% of total TEQ in some animals.

Temporal trends of PCDD, PCDF and PCB levels in muscle meat of herring from different fishing grounds of the Baltic Sea and actual data of different fish species from the Western Baltic Sea

To study the time trend of PCDD, PCDF and dl-PCB levels in the muscle of herring from the Western Baltic Sea, samples were collected in 2006 at the same fishing locations as in 1999. The results demonstrated no obvious change in contamination levels based on content in fat during the last 7 years. The site-dependent increase in WHO-PCDD/F-PCB-TEQ concentrations already found in 1999 in fishing grounds between the Skagerrak and the east of Bornholm could be confirmed by this study. In addition, an overview is given in this study on the actual WHO-TEQ concentrations in cod, eel, herring, sprat and some salmon landed at various fishing ports along the coast of Mecklenburg-Western Pomerania/Germany. All herring samples were found to be below the maximum levels and the concentrations in cod were below 1 ng WHO-TEQ kg(-1) wet weight (ww). The contaminant levels of 28 pooled eel samples varied considerably between 1.35 and 16.75 ng WHO-TEQ kg(-1) ww. The results are discussed in relation to the fat content and to the weight of the eels.

Concentrations, patterns and metabolites of organochlorine pesticides in relation to xenobiotic phase I and II enzyme activities in ringed seals (Phoca hispida) from Svalbard and the Baltic Sea

The present study investigates the concentrations and patterns of organochlorine pesticides (OCPs) and their metabolites in liver and plasma of two ringed seal populations (Phoca hispida): lower contaminated Svalbard population and more contaminated Baltic Sea population. Among OCPs, p,p'-DDE and sum-chlordanes were the highest in concentration. With increasing hepatic contaminant concentrations and activities of xenobiotic-metabolizing enzymes, the concentrations of 3-methylsulfonyl-p,p'-DDE and the concentration ratios of pentachlorophenol/hexachlorobenzene increased, and the toxaphene pattern shifted more towards persistent Parlar-26 and -50 and less towards more biodegradable Parlar-44. Relative concentrations of the chlordane metabolites, oxychlordane and -heptachlorepoxide, to sum-chlordanes were higher in the seals from Svalbard compared to the seals from the Baltic, while the trend was opposite for cis- and trans-nonachlor. The observed differences in the OCP patterns in the seals from the two populations are probably related to the catalytic activity of xenobiotic-metabolizing enzymes, and also to differences in dietary exposure.

Levels and homologue profiles of PCDD/Fs in sediments along the Swedish coast of the Baltic Sea

BACKGROUND, AIM, AND SCOPE

The primary aim of this study was to explore the variations in PCDD/F levels and homologue profiles of Baltic surface sediments by comprehensively analyzing polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in samples from a large number of sites, encompassing not only previously known hotspot areas, but also sites near other potential PCDD/F sources, in pristine reference areas (in which there was no industrial activity) and offshore sites.

MATERIALS AND METHODS

Surface sediment samples (146 in total) were collected at various points along the Swedish coast and offshore areas. In addition, bulk deposition was sampled, monthly, at a single site in northern Sweden during 1 year. The concentrations of tetra- through octa-substituted CDD/Fs were determined in both matrices.

RESULTS

Highly elevated concentrations of PCDD/Fs were found at many sites in coastal areas and concentrations were also slightly elevated in some offshore areas. Homologue profiles varied substantially amongst samples from coastal sites, while those from offshore and other pristine sediments were relatively similar. The offshore sediments showed different profiles from those observed in the deposition samples. Sediment levels of PCDD/Fs were not generally significantly correlated to organic carbon levels, except in some pristine areas. Comparison of data obtained in this and previous studies suggest that both their levels and profiles are similar today to those observed 20 years ago in coastal and offshore areas. The only detected trend is that their levels appear to have decreased slightly in the offshore area of the Bothnian Sea.

DISCUSSION

The localization of hotspot areas along the coast, the lack of consensus between PCDD/F profiles of sediments and general background, and their weak correlations with organic carbon suggest that PCDD/Fs in the study area largely originate from local/regional emissions. However, due to complicating factors such as sediment dynamics and land upheaval, it is not possible to conclude whether these pollutants derive from recent emissions or from a combination of recent emissions and re-distribution of previous inputs.

CONCLUSIONS

The results show that: elevated levels of PCDD/Fs are present in both coastal and offshore areas of the Baltic Sea, the major hotspots are close to the shore, and there are large variations in profiles, indicating that local emissions are (or have been) the major causes of pollution.

RECOMMENDATIONS AND PERSPECTIVES

In order to identify other hotspot areas and trace sources, comprehensive analysis of PCDD/Fs in surface sediments is needed in all areas of the Baltic Sea that have not been previously investigated. The high levels of PCDD/Fs observed in surface sediments also indicate a need to elucidate whether they are due mainly to current emissions or a combination of recent pollution and re-distribution of historically deposited pollutants. To do so, better understanding of sediment dynamics and present-day inputs, such as riverine inputs, industrial effluents, and leakage from contaminated soil is required. There are indications that contaminated sediments have a regional impact on fish contamination levels. However, as yet there is no statistically robust evidence linking contaminated sediments with elevated levels in Baltic biota. It should also be noted that the Baltic Sea is being massively invaded by the deep-burrowing polychaete Marenzielleria ssp., whose presence in sediments has been shown to increase water concentrations of hydrophobic pollutants. In awareness of this, it is clear that high levels in sediments cannot be ignored in risk assessments. In order to investigate the emission trends more thoroughly, analysis of PCDD/Fs in offshore sediment cores throughout the Baltic Sea is also recommended.

Polybrominated diphenyl ethers and their hydroxylated analogues in ringed seals (Phoca hispida) from Svalbard and the Baltic Sea

The present study investigated the concentrations and patterns of PBDEs and hydroxylated (OH) PBDE analogues in two ringed seal populations: less contaminated Svalbard and more contaminated Baltic Sea. Mean concentration of hepatic sigma-PBDE, which was dominated by BDE47, was six times higher in the ringed seals from the Baltic Sea compared to the seals from Svalbard. BDE47/sigma-PBDE was higher in the seals from Svalbard compared to that for Baltic seals, while the trend was opposite for BDE153 and 154. The geographical difference in contaminant pattern of PBDEs in ringed seals could be explained by biotransformation via oxidative metabolism and/or by dietary differences. OH-PBDEs were detectable in the majority of plasma samples from both locations, and dominated by bioaccumulation of naturally occurring congeners. Low levels of 3-OH-BDE47 and 4'-OH-BDE49 in the Baltic ringed seals suggested minor oxidative biotransformation of BDE47. In the Baltic seals, BDE153/sigma-PBDEs and BDE154/sigma-PBDEs increased and BDE28/sigma-PBDE decreased with increasing sigma-POP concentration, which suggests BDE153 and 154 are more persistent than BDE28. Contrasting diets of the ringed seals in these two locations may influence the PBDE congener pattern due to selective long-range transport and direct effluent emissions to Svalbard and the Baltic, respectively.

PCDD/Fs and PCBs in seafood species from Moreton Bay, Queensland, Australia

Previous studies have identified elevated levels of polychlorinated dibenzo-p-dioxins (PCDDs) in sediments and megafauna (dugongs and green turtles) in the marine environment of southeast Queensland, Australia. Little information exists, however, regarding the levels of PCDDs, polychlorinated dibenzofurans (PCDFs) and related polychlorinated biphenyls (PCBs) in seafood from this area. This study aims to establish baseline information on PCDD/F and PCB contamination in a range of seafood species from Moreton Bay and to investigate contaminant variability due to harvesting season, size, habitat location and trophic level. In addition, different seafood extraction methods were tested to evaluate their impact on lipid yields and contaminant concentration. Overall, the median TEQ(DF&PCB) levels in seafood from Moreton Bay were elevated compared to background levels in Australian marine/estuarine and retail fish. However, TEQ(DF&PCB) levels of most seafood analysed were below the respective EU maximum limits. High inter- and intraspecies variability was observed, which could be partially attributed to differences in trophic level, season harvested and habitat location.