Recovery discrepancies of OH-PBDEs and polybromophenols in human plasma and cat serum versus herring and long-tailed duck plasma.

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of polybrominated diphenyl ethers (PBDEs) and/or as natural products. The OH-PBDEs and polybromophenols have come into focus over the last decade due to their abundance in biota and their potential adverse health effects. The present recovery study aims to validate a commonly used method (published by Hovander et al. 2000) for OH-PBDE analysis in human plasma. Further, the authors intended to determine the method's applicability to serum/plasma matrices from other species than humans. The investigated matrices were human plasma, cat serum, herring- and long-tailed duck plasma. The recovery study included nine OH-PBDEs, four polybromophenols and three methoxylated PBDEs (MeO-PBDEs). Five replicates of each matrix were spiked with these compounds at two dose levels; a low dose (0.5 ng) and a high dose (5 ng) and were cleaned up according to the Hovander method. The recovery of OH-PBDEs and polybromophenols in human plasma and cat serum were high and reproducible at both dose levels whereas the recovery for herring and long-tailed duck plasma were low and insufficient with great variability amongst OH-PBDE congeners at both dose levels. Our data show that the method can be fully applied to matrices like human plasma and cat serum but not for herring and long-tailed duck plasma without further method development. Hence care needs to be taken when applying the method onto other blood matrices without validation since the present study have demonstrated that the recoveries may differ amongst OH-PBDE congeners and specie.

Quantitative structure - photodegradation relationships of polybrominated diphenyl ethers, phenoxyphenols and selected organochlorines.

Among other developments, the technological revolution has lead to introduction of new chemicals to better serve in instruments and materials. The consequences of the extensive increase in use of new chemicals can be detected in the environment world wide, i.e. in wildlife and humans. To ensure this problem to be minimised in the future, new chemicals need to be subjected to predictive assessments before commercialised. To facilitate screening, qualitative structure-activity relationships, quantitative structure-activity relationships may be applied to describe reactivity of chemicals. Physico-chemical properties of chemicals such as partition coefficients and half-lives for the various environmental compartments are essential input data in multimedia environmental fate models. In this study we examine how structural characteristics can quantitatively describe laboratory determined photolytic half-lives of halogenated compounds of different classes, such as polybrominated diphenyl ethers (PBDEs), hydroxylated brominated diphenyl ethers (OH-PBDEs), and other organohalogens. A total of 30 chemicals with experimentally measured half-lives are used. Results reveal that the most important descriptors for describing the half-lives of the brominated compounds are the energy gap (GAP-1) between HOMO-1 and LUMO, the lowest partial charge on a halogen atom (Qhal-), topological polar surface area (TPSA), the atom with highest radical superdelocalizability (Rad-super+) and LUMO density (LUMO+).

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.

Maternal and cord serum exposure to PCB and DDE methyl sulfone metabolites in eastern Slovakia.

Polychlorinated biphenyls (PCBs) were commercially produced between 1959 and 1984 in eastern Slovakia. Improper handling led to a highly contaminated local environment and high levels of PCBs in humans and wildlife in the Michalovce area. The aim of this study was to analyse serum for methylsulfonyl metabolites of PCB (MeSO(2)-PCBs) and DDE (3-MeSO(2)-DDE) in serum samples from pregnant women and in a selected number of paired cord blood samples to assess maternal sulfone levels and patterns, and transplacental transfer of these metabolites. The donating women were from two districts in eastern Slovakia. A liquid-liquid extraction method together with separation of substance groups and further clean-up on silica gel columns were applied prior to analysis by gas chromatography/mass spectrometry. 3-MeSO(2)-DDE was the major methyl sulfone in most of the samples followed by a yet not identified MeSO(2)-hexaCB, 4'-MeSO(2)-CB101, 4'-MeSO(2)-CB87 and 4-MeSO(2)-CB149. The women from the contaminated area had three times higher concentrations of the MeSO(2)-PCBs than women from the reference area. This is the first report on methyl sulfone metabolites of PCB and DDE in human cord serum. It is shown that these metabolites are transported through the placenta. The levels of MeSO(2)-PCBs in the maternal serum were about 1.5 times higher than in the corresponding cord serum on a lipid weight basis. For 3-MeSO(2)-DDE, the levels were about the same in maternal and cord serum. The difference in the maternal:cord ratio, comparing MeSO(2)-PCBs with 3-MeSO(2)-DDE might be due to differences in transport through the placenta caused by their different affinities for lipoproteins and plasma proteins.

Polybrominated diphenyl ether exposure to electronics recycling workers--a follow up study.

Workers at an electronics recycling plant have previously been shown to have elevated serum levels of polybrominated diphenyl ethers (PBDEs) compared to referents without occupational PBDE exposure. Subsequent structural changes and industrial hygiene measures at the plant were applied to improve the work environment. The present study aims to assess the impact of these work environment changes on the occupational exposure to PBDEs. Blood were drawn from the workers and analyzed at two different laboratories, and serum concentrations of several PBDE congeners were determined by GC/MS or GC/HRMS. Cross-sectional studies were performed prior to (in 1997; N=19) and after (in 2000; N=27) workplace improvements. Longitudinal studies were performed on twelve of the workers that were sampled at both occasions. Even though the amount of processed goods had doubled in 2000 as compared to 1997, there was a significant decrease in the serum levels of BDE-183 and BDE-209. For BDE-209 the levels observed in year 2000 were even lower than in referents with no occupational exposure. In contrast to the decrease of higher brominated diphenyl ethers, the concentrations of BDE-47 did not significantly change. For BDE-153, the cross-sectional study indicated no change, whereas the longitudinal follow up indicated a significant increase. This study shows that the industrial hygiene improvements clearly reduced the occupational exposure to BDE-183 and BDE-209 at the plant. Still, the levels of hexa- to nonaBDEs but not BDE-209 were elevated, compared to referents with no occupational exposure.