Concentrations of chlorinated and brominated contaminants and their metabolites in serum of harbour seals and harbour porpoises

Laboratory of Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Environment international (Impact Factor: 5.56). 03/2009; 35(6):842-50. DOI: 10.1016/j.envint.2009.02.001
Source: PubMed


Harbour seals (Phoca vitulina) and harbour porpoises (Phocoena phocoena) are top predators in the North Sea and consequently accumulate a variety of pollutants in their tissues. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) were measured in serum of wild harbour seals (n=47) and captive harbour porpoises (n=21). Both species exhibit long life spans and do not have extreme situations, such as complete fasting during periods of lactation, in their annual cycles. For PCBs, concentrations in adult males were slightly higher than in juveniles and lowest in juvenile females. For PBDEs, juveniles have higher levels than adult males and females, probably as a consequence of lactational transfer. However, differences between these age-gender groups were not statistical significant, indicating that individual variation was limited within each species, even without knowing the feeding status of the animals. Body condition, particularly emaciation, has a major influence on the levels of chlorinated and brominated contaminants in serum. Profiles of PCBs were CB 153>CB 138>CB 187>CB 180 and CB 153>CB 138>CB 149>CB 187>CB 180 for harbour seals and porpoises respectively. For PBDEs, BDE 47 was the predominant congener followed by BDE 100 and 99 in both species. In harbour seals, concentrations of sum PCBs (median: 39,200 pg/ml) were more than 200 times higher than levels of sum PBDEs (median: 130 pg/ml) and almost 10 times higher than concentrations of sum HO-PCBs (4350 pg/ml). In harbour porpoises, concentrations of sum PCBs (median: 24,300 pg/ml) were about 20 times higher than concentrations of PBDEs (median: 1300 pg/ml). HO-PCBs were detected in only 4 harbour porpoises and this at very low concentrations. Naturally-produced MeO-PBDEs were only found in harbour porpoises at concentrations ranging from 120 to 810 pg/ml. HO-PBDEs were not found in any species. In general, harbour seals accumulate less compounds and have mostly lower concentrations than harbour porpoises possibly as a result of a better developed metabolism.

Download full-text


Available from: Krishna Das,
  • Source
    • "Newman et al. 1994; Hall et al. 2003; Foltz et al. 2014) as well as in blood (e.g. Newman et al. 1994; Hall et al. 2003; Das et al. 2008; Weijs et al. 2009), but the most important reason for using these tissues is their usefulness in ex vivo/ in vitro experiments. "
    [Show abstract] [Hide abstract]
    ABSTRACT: It is widely recognized that marine mammals are exposed to a wide variety of pollutants, with a weight of evidence indicating impacts on their health. Since hundreds of new chemicals enter the global market every year, the methods, approaches and technologies used to characterize pollution levels or impacts are also in a constant state of flux. However, legal and ethical constraints often limit the type and extent of toxicological research being carried out in marine mammals. Nevertheless, new and emerging in vivo, in vitro as well as in silico research opportunities abound in the field of marine mammal toxicology. In the application of findings to population-, species-, or habitat-related risk assessments, the identification of causal relationships which inform source apportionment is important. This, in turn, is informed by a comprehensive understanding of contaminant classes, profiles and fate over space and time. Such considerations figure prominently in the design and interpretation of marine mammal (eco)toxicology research. This mini-review attempts to follow the evolution behind marine mammal toxicology until now, highlight some of the research that has been done and suggest opportunities for future research. This Special Issue will showcase new developments in marine mammal toxicology, approaches for exposure-effect research in risk assessment as well as future opportunities.
    Archives of Environmental Contamination and Toxicology 10/2015; DOI:10.1007/s00244-015-0233-9 · 1.90 Impact Factor
  • Source
    • "Actually, interspecies differences in the induction and catalytic activity of hepatic CYP isoforms have been reported (Martignoni et al., 2006). Fig. 2 shows the concentration ratios of OH-PCB isomers to their potential precursor PCBs (OH-PCBs/PCBs ratios) in Baikal seals and harbor seals (Weijs et al., 2009). Noticeable different concentration ratios were observed for 4OH-CB187/CB183 + CB187 (Baikal seal: 0.35, Harbor seal: 0.053) and 4OH-CB107/CB105 + CB118 (Baikal Fig. 2. The concentration ratios of OH-PCB isomers to their potential precursor PCBs (OH-PCBs/PCBs ratios) in Baikal seals and harbor seals. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We have previously demonstrated that Baikal seals (Pusa sibirica) are still being exposed to polychlorinated biphenyls (PCBs), and the population is at risk. In the present study, we measured the residue levels of PCBs and their hydroxylated metabolites (OH-PCBs) in the blood of Baikal seals and assessed the impact of OH-PCBs on the thyroid function. Blood concentrations of PCBs and OH-PCBs were in the range of 2.8–130 ng g−1 wet wt. and 0.71–4.6 ng g−1 wet wt., respectively. Concentrations of higher-chlorinated OH-PCBs (hexa- to octa-PCBs) were more than 70% to total OH-PCB concentrations, indicating Baikal seals are mostly risked by higher-chlorinated OH-PCBs. High levels of 4OH-CB146 and 4OH-CB187 and low levels of 4OH-CB107/4′OH-CB108 found in Baikal seals were different from those in other phocidae species, suggesting the unique drug-metabolizing enzyme activities and/or contamination sources in this species. Concentrations of some OH-PCBs in males were significantly higher than those in females. These results suggest that these isomers may be preferentially transferred from mother to pup via cord blood. However, concentrations of almost all the isomers were not significantly correlated with the levels of blood total T3 and T4, implying less impact of PCB-related compounds on the thyroid hormone circulation.
    Chemosphere 11/2014; 114:1–8. DOI:10.1016/j.chemosphere.2014.03.089 · 3.34 Impact Factor
  • Source
    • "It has been also suggested that organisms that are more exposed to environmental contaminants may have greater biotransformation capacities as a consequence of contaminant-mediated induction of xenobiotic-metabolizing enzymes such as CYPs (Houde et al. 2006). In addition, it can be also presumed that marine mammals can accumulate not only PCBs but also OH- PCBs (Hoekstra et al. 2003; Houde et al. 2006; Weijs et al. 2009); thus, exposure to OH-PCBs might also be from food chain transfer in addition to metabolic processes. Bytingsvik et al. (2012) have observed decreasing levels of OH-PCBs in Svalbard polar bear mothers and cubs from 1998 (Σ 6 OH-PCBs=228±60 and 98±23 ng g −1 w/w, respectively) via 2002 (Σ 11 OH-PCBs= 173 ng g −1 w/w in polar bear mothers) to 2008 (Σ 6 OH-PCBs=80±38 and 49±21 ng g −1 w/w, respectively), which are in accordance with the temporal trend of decreasing levels of PCBs in arctic wildlife (Verreault et al. 2005; Wolkers et al. 2008; McKinney et al. 2011). "
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, attention has been directed to chemicals with possible endocrine-disrupting properties. Polychlorinated biphenyls (PCBs) and their metabolites belong to one group of environmental contaminants that have been shown to interact with the endocrine system in mammals, including humans. Although recent developments have been made in terms of determination of PCB metabolites in blood samples, still limited number of studies have been able to elucidate their profiles and toxicological and health effects in humans. This review aims to evaluate and compare the levels of hydroxylated PCBs (OH-PCBs) and methyl sulfone PCBs (MeSO2-PCBs) in blood and their relationship to parent compounds and also address the potential risks and adverse health effects in humans. Levels of OH-PCBs varied between 0.0002 and 1.6 ng g−1 w/w in human serum/plasma from the selected literature, correlating well with ∑PCBs. In contrast, ∑OH-PCB/∑PCB ratio in animals did not show a significant correlation, which might suggest that the bioaccumulation plays an even more important role in the concentration of OH-PCBs compared to PCB metabolism. Highest levels of MeSO2-PCBs were reported in marine mammals with high selectivity retention in the liver. Health effects of PCB metabolites included carcinogenicity, reproductive impairment, and developmental neurotoxicity, being more efficiently transferred to the brain and across the placenta from mother to fetus in comparison to the parent PCBs. Based on the lack of knowledge on the occurrence and distribution of lower chlorinated OH-PCBs in humans, further studies to identify and assess the risks associated to human exposure are essential.
    Environmental Science and Pollution Research 06/2014; 21(20). DOI:10.1007/s11356-014-3136-9 · 2.83 Impact Factor
Show more