Polybrominated diphenyl ethers (PBDEs) in mussels from cultures and natural population

Insights into the combined toxicity and mechanisms of BDE-47 and PFOA in marine blue mussel: An integrated study at the physiochemical and molecular levels

The coexistence of multiple emerging contaminants imposes a substantial burden on the ecophysiological functions in organisms. The combined toxicity and underlying mechanism requires in-depth understanding. Here, marine blue mussel (Mytilus galloprovincialis L.) was selected and exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and perfluorooctanoic acid (PFOA) individually and in combination at environmental related concentrations to elucidate differences in stress responses and potential toxicological mechanisms. Characterization and comparison of accumulation, biomarkers, histopathology, transcriptomics and metabolomics were performed. Co-exposure resulted in differential accumulation patterns, exacerbated histopathological alterations, and different responses in oxidative stress and biomarkers for xenobiotic transportation. Moreover, the identified differentially expressed genes (DEGs) and differential metabolites (DEMs) in mussels were found to be annotated to different metabolic pathways. Correlation analyses further indicated that DEGs and DEMs were significantly correlated with the above biomarkers. BDE-47 and PFOA altered the genes and metabolites related to amino acid metabolism, energy and purine metabolism, ABC transporters, and glutathione metabolism to varying degrees, subsequently inducing accumulation differences and combined toxicity. Furthermore, the present work highlighted the pivotal role of Nrf2-keap1 detoxification pathway in the acclimation of M. galloprovincialis to reactive oxygen species (ROS) stress induced by BDE-47 and PFOA. This study enabled more comprehensive understanding of combined toxic mechanism of multi emerging contaminants pollution.

Anthropogenic (PBDE) and naturally-produced (MeO-PBDE) brominated compound levels in Bizerte Lagoon clams (Ruditapes decussatus): Levels and human health risk assessment

Information on the occurrence of organobrominated compounds in bivalves from Tunisia is scarce. To the best of our knowledge, this is the first report of these compounds in clams from Tunisia. The aim of this study is to measure natural and synthetic organobrominated compound concentrations and evaluate congener distribution and pollution sources in a clam species (Ruditapes decussatus) from three sites of the Bizerte Lagoon. Total synthetic organobrominated pollutant levels in clam ranged from 34.8 to 188ngg^-1lw. For natural organobrominated compounds, concentrations varied from 18.2 to 49.5ngg^-1lw. Total PBDE and MeO-PBDE concentrations in clams from the Bizerte Lagoon were similar or slightly lower than those reported for other species from other locations around the world. The health risks associated with the consumption of this species were assessed and posed no threat to public health concerning PBDE intakes.

Influence of human activities and organic matters on occurrence of polybrominated diphenyl ethers in marine sediment core: A case study in the Southern Yellow Sea, China

The Southern Yellow Sea (SYS) is an important reservoir of anthropogenic organic contaminants, such as polybrominated diphenyl ethers (PBDEs). To reconstruct the historical records of PBDEs and examine their relationships with the human activities and organic matters, a²¹⁰Pb-dated sediment core was collected from the central mud area in the SYS. The concentrations of tri-to hepta-BDEs (∑₇PBDEs) and BDE-209 ranged from 9.8 to 99.8 pg g^-1 d.w. and from 12.1 to 855.4 pg g^-1 d.w., respectively, both displaying the increasing trends from the bottom to the surface. More importantly, there was a faster increase for PBDEs since the 1990s, especially for BDE-209, which responded well with the rapid economic growth, and the increases of urbanization and industrialization in the local areas of the SYS. The analogously vertical patterns and significant relationships between PBDEs and total organic carbon (TOC) implied the TOC-dependent deposition of PBDEs in the core. Furthermore, multiple biomarker-based proxies of terrestrial organic matter (TOM) and marine organic matter (MOM) were introduced to systematically investigate the different effects of TOM and MOM on PBDE deposition in the SYS. The similarly down-core profiles and significant correlations were found between PBDEs and the MOM proxies (sum of rassicasterol, dinosterol and C₃₇ alkenones (∑A + B + D) and marine TOC) as well as the branched and isoprenoid tetraether (BIT), but not for TOM proxies (∑C₂₇+C₂₉+C₃₁n-alkanes, terrestrial and marine biomarker ratio (TMBR) and terrestrial TOC), indicating that MOM was an important factor driving PBDE deposition in the sediment core from the SYS.

Quantification of polybrominated diphenyl ethers (PBDEs) in food. A review

The polybrominated diphenyl ethers (PBDEs), a class of brominated flame retardants (BFRs), are food contaminants of animal origin. Interest in food matrices analysis is growing due to the toxicity of PBDEs and European Commission (EC) recommendation (118/2014/EU). Here we review papers concerning methods of PBDEs analysis while focusing on extraction, clean up, chromatographic separation and detection techniques. The emphasis is put on EC recommendation, the congeners and the efficiency of different detection systems. Some analytical problems caused by differences between low- and high-molecular-mass congener properties, especially the possible limitations of BDE-209 analysis, are discussed. Detection techniques and mass spectrometry (MS) ionization modes applied to PBDE level determination in food of animal origin are compared. The gas chromatography (GC) coupled to high-resolution MS is undoubtedly fit for that purpose, but ion trap MS could be used to PBDEs determination as well. ECD is the most sensitive technique; however, other halogen compounds present in sample may interfere with PBDEs congeners necessitating results confirmation. Moreover, the novel atmospheric pressure chemical ionization (APCI) method applied to GC in tandem with MS places this technique in the top category of the most sensitive techniques which may be used.