| 1. |
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| 2. |
- Sobek, Anna, et al.
(författare)
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Coastal sediments in the Gulf of Bothnia as a source of dissolved PCDD/Fs and PCBs to water and fish
- 2014
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 487, s. 463-470
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Tidskriftsartikel (refereegranskat)abstract
- High levels of PCDD/Fs and PCBs in Baltic Sea biota have been a matter of great concern during the last decades. We measured the freely dissolved concentrations of PCDD/Fs and PCBs in sediment pore water and bottom water in eight areas along the Swedish coast of the Gulf of Bothnia, by using state-of-the-art passive samplers. Chemical activity ratios (calculated from freely dissolved concentrations in pore water and bottom water based on chemical activity ratios) for PCDD/Fs were higher than 1 at all stations (PCDD/Fs average 27; stdev 22). High activity ratios suggest that the sediments have a potential to act as a source of dissolved PCDD/Fs to the water column. Activity ratios for PCBs varied between 0.3 and 17 (average 2; stdev 4). The concentrations of PCDD/Fs and PCBs in bottom water were significantly correlated with concentrations in sediment pore water (p < 0.00001 to p = 0.03) as well as with concentrations in juvenile perch caught in the same areas (p < 0.00001 to p = 0.02). To our knowledge, this is the first study demonstrating a correlation between in-situ measured freely dissolved PCDD/F concentrations and lipid-normalized contents in stationary fish. Our results confirm that freely dissolved concentrations should be used as chemical predictors of bioaccumulation. The results from this study imply that continued efforts to reduce levels of PCDD/Fs and PCBs in coastal sediments will have positive effects on concentrations of these contaminants in lower trophic levels of Baltic Sea ecosystems.
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| 3. |
- Apler, Anna, 1980-
(författare)
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Dispersal and environmental impact of contaminants in organic rich, fibrous sediments of industrial origin in the Baltic Sea
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The health of the Baltic Sea is negatively affected by hazardous substances such as metals and persistent organic pollutants (POPs), which include legacy pollutants that were banned decades ago, but still circulate in the ecosystem. Elevated levels of legacy pollutants, identified by HELCOM as key hazardous substances, have been found in accumulations of fibrous sediments, so-called fiberbanks and fiber-rich sediments, which derive from old pulp mills along the Swedish north coast. The fiberbanks are deposited in shallow water and bathymetrical models show evidence of their erosion, potentially caused by propeller wash, submarine landslides and gas ebullition. This thesis addresses the potential dispersal of key substances from three fiberbank sites located in a non-tidal Swedish estuary, in which metals and POPs are present in concentrations that may pose a risk for benthic organisms. Metals and POPs are partitioned to organic material and, as expected, show the highest partitioning coefficients (KD) in fiberbanks that have higher TOC levels compared to adjacent areas with fiber-rich sediments (natural clay sediments mixed up with fibers) or relatively unaffected postglacial clays. However, many analytes were found to be present in quantifiable concentrations in pore water, which indicates diffusion of substances from the solid phase to the aqueous phase. To assess the dispersive influence of an abrupt erosional event on dispersion, metals were measured in undisturbed bottom water and in bottom water disturbed by artificial re-suspension of fibrous sediments. The bioavailable, dissolved fraction of metals decreased in bottom water after re-suspension, probably due to the particle concentration effect. In contrast, the total concentrations of metals and number of quantifiable metals increased with particle concentration caused by re-suspension. At one station, the total concentration of chromium (Cr) was elevated to a level where it may lower the ecological status of the water body during periods of substantial erosion (e.g. spring floods or submarine landslides). Analyses of disturbed bottom water revealed, however, that minerogenic particles were preferentially re-suspended compared to organic. This suggests that physical erosion and re-suspension of fiberbank sediments might have a larger effect on dispersal of metals than on POPs.
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| 4. |
- Assefa, Anteneh Taye, et al.
(författare)
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Assessment of PCDD/F Source Contributions in Baltic Sea Sediment Core Records
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851 .- 1086-931X .- 1520-6912. ; 48:16, s. 9531-9539
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Tidskriftsartikel (refereegranskat)abstract
- Spatial and temporal trends of sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea were evaluated by positive matrix factorization (PMF) and principal component analysis (PCA). Sediment cores were sampled at eight coastal, one coastal reference, and six offshore sites covering the northern to the southern Baltic Sea. The cores, which covered the period 1919-2010, were sliced into 2-3 cm disks among which 8-11 disks per core (in total 141 disks) were analyzed for all tetra- through octa-CDD/Fs. Identification and apportionment of PCDD/F sources was carried out using PMF. Five stable model PCDD/F congener patterns were identified, which could be associated with six historically important source types: (i) atmospheric background deposition (ABD), (ii) use and production of pentachlorophenol (PCP), (iii) use and production of tetra-chlorophenol (TeCP), (iv) high temperature processes (Thermal), (v) hexa-CDD-related sources (HxCDD), and (vi) chlorine-related sources (Chi), all of which were still represented in the surface layers. Overall, the last four decades of the period 1920-2010 have had a substantial influence on the Baltic Sea PCDD/F pollution, with 88 +/- 7% of the total amount accumulated during this time. The 1990s was the peak decade for all source types except TeCP, which peaked in the 1980s in the northern Baltic Sea and has still not peaked in the southern part. The combined impact of atmospheric-related emissions (ABD and Thermal) was dominant in the open sea system throughout the study period (1919-2010) and showed a decreasing south to north trend (always >80% in the south and >50% in the north). Accordingly, to further reduce levels of PCDD/Fs in the open Baltic Sea ecosystem, future actions should focus on reducing atmospheric emissions.
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| 5. |
- Assefa, Anteneh Taye, et al.
(författare)
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Temporal Trends of PCDD/Fs in Baltic Sea Sediment Cores Covering the 20th Century
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:2, s. 947-953
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Tidskriftsartikel (refereegranskat)abstract
- The pollution trend of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea region was studied based on depth profiles of PCDD/Fs in sediment cores collected from six-offshore areas, eight coastal sites impacted by industrial/urban emissions, and one coastal reference site. A general trend was observed for the offshore and coastal reference sites with substantial increase in PCDD/F concentrations in the mid-late 1970s and peak levels during 1985-2002. The overall peak year for PCDD/Fs in Baltic Sea offshore areas was estimated (using spline-fit modeling) to 1994 +/- 5 years, and a half-life in sediments was estimated at 29 +/- 11 years. For the industrial/urban impacted coastal sites, the temporal trend was more variable with peak years occurring 1-2 decades earlier compared to offshore areas. The substantial reductions from peak levels (38 +/- 11% and 81 +/- 12% in offshore and coastal areas, respectively) reflect domestic and international actions taken for reduction of the release of PCDD/Fs to the environment. The modeled overall half-life and reductions of PCDD/Fs in offshore Baltic Sea sediment correspond well to both PCDD/F trends in European lakes without any known direct. PCDD/F sources (half-lives 30 and 32 years), and previously modeled reduction in atmospheric deposition of,PCDD/Fs to the Baltic Sea since 1990. These observations support previous findings of a common diffuse source, such as long-range air transport of atmospheric emissions, as the prime source of PCDD/Fs to the Baltic Sea region. The half-life of PCDD/Fs in Baltic Sea offshore sediments was estimated to be approximately 2 and 4-6 times longer than in semirural and urban European air, respectively. This study highlights the need for further international actions to reduce the levels of PCDD/Fs in Baltic Sea air specifically and in European air in general.
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| 6. |
- Gyllenhammar, Irina, et al.
(författare)
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Perfluoroalkyl Acids (PFAAs) in Children's Serum and Contribution from PFAA-Contaminated Drinking Water
- 2019
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 53:19, s. 11447-11457
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Tidskriftsartikel (refereegranskat)abstract
- We investigated associations between serum perfluoroalkyl acid (PFAA) concentrations in children aged 4, 8, and 12 years (sampled in 2008-2015; n = 57, 55, and 119, respectively) and exposure via placental transfer, breastfeeding, and ingestion of PFAA-contaminated drinking water. Sampling took place in Uppsala County, Sweden, where the drinking water has been historically contaminated with perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), perfluoroheptanoate (PFHpA), and perfluorooctanoate (PFOA). PFOS showed the highest median concentrations in serum (3.8-5.3 ng g(-1) serum), followed by PFHxS (1.6-5.0 ng g(-1) serum), PFOA (2.0-2.5 ng g(-1) serum), and perfluorononanoate (PFNA) (0.59-0.69 ng g(-1) serum) in children. Including all children, serum PFOA, PFHxS, and PFOS concentrations (adjusted mean), respectively, per unit (ng g(-1) serum) of increase in the maternal serum level (at delivery), the associations being strongest for 4 year-old children. PFHxS and PFOS significantly increased 3.9 and 3.8%, respectively, per month of nursing, with the highest increase for 4 year-olds. PFOA, PFBS, PFHxS, and PFOS increased 1.2, 207, 7.4, and 0.93%, respectively, per month of cumulative drinking water exposure. Early life exposure to PFOA, PFHxS, and PFOS is an important determinant of serum concentrations in children, with the strongest influence on younger ages. Drinking water with low to moderate PFBS, PFHxS, PFOS, and PFOA contamination is an important source of exposure for children with background exposure from other sources.
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| 7. |
- Gyllenhammar, Irina, et al.
(författare)
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Perfluoroalkyl Acids (PFAAs) in Serum from 2-4-Month-Old Infants : Influence of Maternal Serum Concentration, Gestational Age, Breast-Feeding, and Contaminated Drinking Water
- 2018
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 52:12, s. 7101-7110
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about factors influencing infant perfluorinated alkyl acid (PFAA) concentrations. Associations between serum PFAA concentrations in 2-4-month-old infants (n = 101) and determinants were investigated by multiple linear regression and general linear model analysis. In exclusively breastfed infants, maternal serum PFAA concentrations 3 weeks after delivery explained 13% (perfluoroundecanoic acid, PFUnDA) to 73% (perfluorohexanesulfonate, PFHxS) of infant PFAA concentration variation. Median infant/maternal ratios decreased with increasing PFAA carbon chain length from 2.8 for perfluoroheptanoic acid and perfluorooctanoic acid (PFOA) to 0.53 for PFUnDA and from 1.2 to 0.69 for PFHxS and perfluorooctanesulfonate (PFOS). Infant PFOA, perfluorononanoic acid (PFNA), and PFOS levels increased 0.7-1.2% per day of gestational age. Bottle-fed infants had mean concentrations of PFAAs 2 times lower than and a mean percentage of branched (%br) PFOS isomers 1.3 times higher than those of exclusively breast-fed infants. PFOA, PFNA, and PFHxS levels increased 8-11% per week of exclusive breast-feeding. Infants living in an area receiving PFAA-contaminated drinking water had 3-fold higher mean perfluorobutanesulfonate (PFBS) and PFHxS concentrations and higher mean %br PFHxS. Prenatal PFAA exposure and postnatal PFAA exposure significantly contribute to infant PFAA serum concentrations, depending on PFAA carbon chain length. Moderately PFBS- and PFHxS-contaminated drinking water is an important indirect exposure source.
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| 8. |
- Sobek, Anna, et al.
(författare)
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Baltic Sea sediment records : Unlikely near-future declines in PCBs and HCB
- 2015
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 518, s. 8-15
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive study on PCBs and HCB in dated sediment cores from the Baltic Sea covering the 20th century, and compare their spatiotemporal trends with those of PCDD/Fs from the same areas. PCB concentrations in coastal impacted sediment followed the temporal trend of estimated global emissions of PCBs and thus responded quickly to changes in global industrial use, whereas concentrations in offshore sediment needed 10-20 years longer to respond. Differences in spatiotemporal trends of PCDD/Fs and PCBs were smaller than expected based on documented differences in key sources and source areas. Sediment concentrations of HCB varied little over time and space, but concentrations are increasing in recent years. The steep PCB concentration reduction over time observed for the late 20th century levelled off during the last 20 years, and levels of PCBs appear to be at or near a steady-state condition. Capsule: PCB concentrations in Baltic Sea sediments appear to be at or near steady-state, and no significant concentration decreases are to be expected in the near future.
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| 9. |
- Sundqvist, Kristina, 1978-, et al.
(författare)
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Congener fingerprints of tetra- through octa-chlorinated dibenzo-p-dioxins and dibenzofurans in Baltic surface sediments and their relations to potential sources
- 2009
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Ingår i: Chemosphere. - : Elsevier Ltd. - 0045-6535. ; 77:5, s. 612-20
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive congener fingerprints of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), including non-2,3,7,8-substituted congeners, in 142 surface sediment samples from the Baltic Sea were characterized by Principal Component Analysis (PCA). The pattern analysis revealed source specific indicators of chlorophenol use, high temperature processes, chlorine bleach/chloralkali production and a source signature suggested to originate from pulp/paper or related production. Congener patterns in sediments from offshore and pristine coastal areas showed strong resemblance to patterns of atmospheric deposition and flue gases, indicating that these sources have high impact in areas that are not affected by point sources. Prominent contributors to the patterns of hotspot areas along the Swedish coast included chlorophenol indicators and a source characterized by hexa-CDDs while the contribution of the traditional chlorine bleach pattern was weaker. This study demonstrates the importance of comprehensive PCDD/F congener analysis for identifying links to candidate sources.
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| 10. |
- Sundqvist, Kristina, 1978-, et al.
(författare)
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Levels and homologue profiles of PCDD/Fs in sediments along the Swedish coast of the Baltic Sea
- 2009
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Ingår i: Environmental Science and Pollution Research. - : Springer Science. - 0944-1344 .- 1614-7499. ; 16:4, s. 396-409
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Tidskriftsartikel (refereegranskat)abstract
- 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. Electronic supplementary material The online version of this article (doi:10.1007/s11356-009-0110-z) contains supplementary material, which is available to authorized users.
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