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- McLachlan, Michael S., et al.
(författare)
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Using Model-Based Screening to Help Discover Unknown Environmental Contaminants
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:13, s. 7264-7271
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Tidskriftsartikel (refereegranskat)abstract
- Of the tens of thousands of chemicals in use, only a small fraction have been analyzed in environmental samples. To effectively identify environmental contaminants, methods to prioritize chemicals for analytical method development are required. We used a high-throughput model of chemical emissions, fate, and bioaccumulation to identify chemicals likely to have high concentrations in specific environmental media, and we prioritized these for target analysis. This model-based screening was applied to 215 organosilicon chemicals culled from industrial chemical production statistics. The model-based screening prioritized several recognized organosilicon contaminants and generated hypotheses leading to the selection of three chemicals that have not previously been identified as potential environmental contaminants for target analysis. Trace analytical methods were developed, and the chemicals were analyzed in air, sewage sludge, and sediment. All three substances were found to be environmental contaminants. Phenyl-tris(trimethylsiloxy)silane was present in all samples analyzed, with concentrations of similar to 50 pg m(-3) in Stockholm air and similar to 0.5 ng g(-1) dw in sediment from the Stockholm archipelago. Tris(trifluoropropyl)trimethyl-cyclotrisiloxane and tetrakis(trifluoropropyl)tetramethyl-cyclotetrasiloxane were found in sediments from Lake Mjosa at similar to 1 ng g(-1) dw. The discovery of three novel environmental contaminants shows that models can be useful for prioritizing chemicals for exploratory assessment.
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| 4. |
- Haglund, Peter, et al.
(författare)
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Brominated dibenzo-p-dioxins: A new class of marine toxins?
- 2007
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 41:9, s. 3069-3074
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Tidskriftsartikel (refereegranskat)abstract
- Levels of polybrominated dibenzo-p-dioxins (PBDDs) were measured in marine fish, mussels, and shellfish. PBDDs were nondetectable in samples from freshwater environments, and their levels were successively higher in samples from the marine environments of the Bothnian Bay and Bothnian Sea, the West Coast of Sweden, and the Baltic Proper. In Baltic Proper littoral fish the levels of PBDDs generally exceeded those of their chlorinated analogues (PCDDs). This is alarming as some Baltic fish species already are contaminated by chlorinated dioxins to such an extent that they cannot be sold on the European market. By comparing spatial trends in PBDD and PCDD distributions, and PBDD patterns in fish, mussels, and algae, we show that the PBDDs are probably produced naturally, and we propose a route for their biosynthesis. We further show that the levels of PBDDs are high (ng/g wet weight) in mussels, and that the levels increase over time. Finally, we discuss the possibility that the PBDDs have adverse biological effects, and that the levels are increasing as a result of global warming and eutrophication.
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| 6. |
- Haglund, Peter, et al.
(författare)
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Temporal Variations of Polybrominated Dibenzo-p-Dioxin and Methoxylated Diphenyl Ether Concentrations in Fish Revealing Large Differences in Exposure and Metabolic Stability
- 2010
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 44:7, s. 2466-73
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Tidskriftsartikel (refereegranskat)abstract
- The concentrations of polybrominated dibenzo-p-dioxins (PBDDs) and polybrominated methoxylated diphenyl ethers (MeO-PBDEs) were investigated in perch (Perca fluviatilis) collected from a Baltic Sea background contaminated area between 1990 and 2005. No temporal trend was found, but large variations were observed - up to 5-fold and 160-fold differences in MeO-PBDE and PBDD concentrations, respectively - between consecutive years, suggesting that retention of these compounds, particularly the PBDDs, is limited. Examination of the congener profiles using principal component analysis (PCA) and correlation analysis indicated that MeO-PBDEs without adjacent substituents (6-MeO-BDE47) or with two adjacent substituents (2'-MeO-BDE68 and 6-MeO-BDE90) are retained more than MeO-PBDEs with three adjacent substituents (6-MeO-BDE85 and 6-MeO-BDE99) and that 1,3,6,8-tetraBDD and 1,3,7,9-tetraBDD are retained more than the other PBDDs which have vicinal hydrogen. Debromination could explain the limited retention of 6-MeO-PBDE85 and 6-MeO-BDE99 and the absence of 2-MeO-BDE123 and 6-MeO-BDE137, and cytochrome P-450 mediated oxidation could explain the limited retention of PBDDs containing vicinal hydrogen. The levels of organobromines, especially MeO-PBDEs, were found to covary with water conditions related to primary production, for example temperature, depth visibility, and inorganic nutrient concentrations, which also favor fish productivity. The results suggest natural production of MeO-PBDEs and PBDDs and imply that they fluctuate considerably over time, as do common marine toxins in fish. Thus, assessments of human and environmental risk should consider both the average and peak concentrations of these contaminants in marine biota.
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| 8. |
- Löfstrand, Karin, et al.
(författare)
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Brominated phenols, anisoles, and dioxins present in blue mussels from the Swedish coastline
- 2010
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 17:8, s. 1460-1468
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Tidskriftsartikel (refereegranskat)abstract
- 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. Materials and methods The samples were liquid–liquid extracted, separated into a phenolic and a neutral fraction, and subsequently analyzed by gas chromatography–mass spectrometry (GS-MS). Results and discussion The levels of OH-PBDEs, MeO-PBDEs and PBDDs were significantly higher in Baltic Sea mussels than in those from the west coast, whereas the levels of PBPs and PBAs displayed the opposite pattern. The blue mussels from the Baltic Sea contained high levels of all analyzed substances, much higher than the levels of, e.g., polybrominated diphenyl ethers. In addition, the GC-MS chromatogram of the phenolic fraction of the west coast samples was dominated by four unknown peak clusters, three of which were tentatively identified as dihydroxy-PBDEs and the other as a hydroxylated-methyl-tetraBDE. Conclusions Clearly, all of the compounds analyzed are natural products, both in the Baltic and the North Sea. However, the geographical differences in composition may indicate different origin, e.g., due to differences in the occurrence and/or abundance of various algae species along these two coasts or possibly a more extensive dilution on the west coast.
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| 10. |
- Malmvärn, Anna, 1966-
(författare)
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Brominated natural products at different trophic levels in the Baltic Sea : Identification of polybrominated dioxins, hydroxylated and methoxylated diphenyl ethers
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Over time, the Baltic Sea has been contaminated by increasing discharges of pollutants from human activities. Persistent organic pollutants (POPs) have caused toxic effects in wildlife and excess of nutrients have led to eutrophication. Furthermore, there are indications that certain polyhalogenated compounds similar in structure to man-made POPs are produced by the biota present in this sea. In the late 1990’s both methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and hydroxylated-PBDEs (OH-PBDEs) were identified in fish and seals living in this environment. OH-PBDEs can originate from metabolism of PBDEs, but both OH- and MeO-PBDEs are also known to be natural products in marine environments. Another group of POPs, the polybrominated dibenzo-p-dioxins (PBDDs), are not produced commercially, but are known to be by-products of chemical industry and of the combustion of, e.g., brominated flame retardants (BFRs). In contrast to the OH- and MeO-PBDEs, PBDDs have not previously been shown to be natural products, although certain related compounds have been indicated to have a natural origin.This thesis describes the identification of PBDDs, OH-PBDEs and MeO-PBDEs in algae, blue mussels and fish living in the Baltic Sea. Several of these compounds were also detected in cyanobacteria. Moreover, PBDDs were present in fish, mussels, shrimp and crabs from different regions of the Baltic Sea and from the west coast of Sweden, but not in organisms from freshwater environments. The levels of these compounds in Baltic fish generally exceeded those of their chlorinated analogues. The origin of the PBDDs identified is somewhat unclear, but the high levels present in blue mussels and the pattern of congeners observed indicate natural production. The presence of PBDDs, OH-PBDEs and MeO-PBDEs in fish and shellfish constitutes a potential risk to both humans and wildlife and requires further investigation.
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