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- Lundgren, Kjell, et al.
(författare)
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Flux estimates and sedimentation of polychlorinated naphthalenes in the northern part of the Baltic sea
- 2003
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Ingår i: Environmental Pollution. - 0269-7491 .- 1873-6424. ; 126:1, s. 93-105
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Tidskriftsartikel (refereegranskat)abstract
- The concentrations and fluxes of polychlorinated naphthalenes (PCNs) were measured in surface sediments, and settling particulate matter collected in sediment traps, at two coastal and two offshore sampling stations in the Gulf of Bothnia, northern Baltic Sea, Sweden. The PCN concentrations (of tetra- to hepta-chloro congeners) in the surface sediments ranged from 0.27 to 2.8 ng/g dry weight and were of the same order of magnitude as background concentrations reported previously in Europe. The PCN fluxes in the southern basin (0.93 and 0.86 μg/m2/year) of the Gulf of Bothnia were higher than those in the northern basin (0.58 and 0.49 μg/m2/year); they were also higher near the coast than in the open sea. These PCN fluxes are similar to the pre-industrial levels determined from lake sediments in northwest England. The PCN homologue distribution changed from a relatively even distribution in samples collected near the coast, to TeCNs dominating in the samples from the open sea. This indicates that higher chlorinated PCNs are deposited and retained in sediments to a higher degree near the coast. The total annual deposition of PCNs in sediments in the Gulf of Bothnia was estimated to be 91 kg/year. Background concentrations in sediments, fluxes and annual sedimentation rates of polychlorinated naphthalenes were measured and estimated at two coastal and two offshore remote sampling stations in the Gulf of Bothnia, northern Baltic Sea.
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| 2. |
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| 3. |
- Lundgren, Kjell, et al.
(författare)
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Polychlorinated Naphthalene Levels, Distribution, and Biomagnification in a Benthic Food Chain in the Baltic Sea
- 2002
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 36:23, s. 5005-13
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Tidskriftsartikel (refereegranskat)abstract
- The scientific literature contains little information regarding bioaccumulation and biomagnification of polychlorinated naphthalenes (PCNs) in food webs. Here we present new information on the food chain transfer of PCNs within a food chain in a subarctic environment. PCNs (tetra- to hepta-chloro congeners) were measured in surface sediments and in a marine benthic food chain, comprising amphipods, isopods, and fourhorned sculpins. Samples were collected from five locations in the Gulf of Bothnia, northern Baltic Sea. PCN concentrations in the sediments were similar to background levels determined previously in sediments from the northern hemisphere. Measurement of the carbon content of the sediments allowed the calculation of biota to sediment accumulation factors (BSAFs). Tetra- and penta-CNs exhibited BSAF values greater than one, while BSAFs for the more chlorinated PCNs were less than one. This suggests more efficient assimilation, by amphipods, of the less chlorinated PCNs. A decrease in PCN concentrations from the lowest to the highest trophic level was demonstrated (amphipods: 10-69 ng/g lw; isopods: 3.9-16 ng/g lw; fourhorned sculpins: 0.54-1.5 ng/g lw). Biomagnification factors (BMFs) were calculated based on the concentrations of the congeners. These indicated that a few congeners biomagnified significantly: the highest BMFs (0.09-1.4) were found for 2,3,6,7-substituted congeners and those lacking adjacent hydrogen-substituted carbon atoms.
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| 4. |
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| 5. |
- Noaksson, Erik, et al.
(författare)
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Gonad development and plasma steroid profiles by HRGC/HRMS during one reproductive cycle in reference and leachate-exposed female perch (Perca fluviatilis)
- 2004
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Ingår i: Toxicology and Applied Pharmacology. - : Elsevier BV. - 0041-008X .- 1096-0333. ; 195:2, s. 247-261
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine processes were studied in reference female perch (Perca fluviatilis) from Lake Djursjön and in leachate-exposed females from Lake Molnbyggen during one reproductive cycle. A high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) technique enabled the analysis of circulating sex steroids [progesterone (P), 17α-hydroxyprogesterone (17α-OHP), androstenedione (A), testosterone (T), estrone (E1), and 17β-estradiol (E2)], the maturation-inducing hormone (MIH) 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-P), and glucocorticoids [11-deoxycortisol (11-DC) and cortisol]. Body and organ measurements, ratio of sexually mature (SM) females, and frequencies of body lesions, were also recorded. High frequencies of body lesions and a low ratio of SM females were generally found in Molnbyggen. These females also had lower gonadosomatic index (GSI) and liver-somatic index (LSI) in the early stages of vitellogenesis, indicating either a delayed onset of oogenesis or an impaired vitellogenesis. Non-reproducing females from both lakes showed a similar LSI cycle as SM females. Increasing T and A levels in SM females from Djursjön coincided with the GSI peak at the time of spawning. These two androgens were on several occasions lower in SM females from Molnbyggen, possibly the result of a disrupted 17,20-lyase activity of the P450 17α enzyme because only minor effects were observed on circulating P and 17α-OHP levels. E2 and E1 levels increased during vitellogenesis in females from both lakes, with E1 levels more closely resembling the peaks of A and GSI. Peak levels of 17α,20β-P at the time of spawning confirmed its function as the MIH in perch, while the simultaneous peak of 11-DC suggests that it also may be involved in final maturation of the oocytes.
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| 6. |
- Persson, Johan N, et al.
(författare)
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Soot-Carbon Influenced Distribution of PCDD/F in the Marine Environment of the Grenlandsfjords, Norway
- 2002
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Ingår i: Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 36:23, s. 4968-4974
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Tidskriftsartikel (refereegranskat)abstract
- The particle associations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were studied in both the water column and the surface sediments of a marine fjord system and were found to poorly obey expectations from the organic matter partitioning (OMP) paradigm. The field observations were instead consistent with the presence of a stronger sorbent subdomain such as pyrogenic soot-carbon (SC) playing an important role in affecting the environmental distribution and fate of PCDD/Fs. Solid-water distribution coefficients (Kd) of PCDD/Fs actually observed in the water column were several orders of magnitude above predictions from a commonly used OMP model. Even when these elevated Kd values were normalized to the particulate organic carbon (POC) content (i.e., KOC), the variability in KOC for individual PCDD/Fs at different fjord locations and seasons of factors 100-1000 suggested that bulk organic matter was not the governing sorbent domain of the suspended particles. Further, POC-normalized particle concentrations of PCDD/Fs (COC) in a vertical profile (surface water-bottom water-surface sediment) revealed a strong increasing trend with depth. Factors of about 100 higher COC for all PCDD/Fs in the sediment than in the surface water could not be explained by higher fugacity in the surrounding deep water nor with C:N or δ13C indexes of selective aging of the bulk organic matter. Instead this was hypothesized to reflect selective preservation of a more recalcitrant and highly sorbing, but minor, subdomain such as soot. The extent of enhanced PCDD/F sorption, above the OMP predictions, was positively correlated with the SC:POC ratio of the suspended particles in surface and deep waters. Finally, the geographical distribution of sedimentary PCDD/F concentrations were better explained by the SC content than by the bulk OC content of the sediment. Altogether, these field-based findings add to recent laboratory-based sorption studies to suggest that we need to consider both amorphous OC partitioning domains and SC particles as carriers of planar aromatic contaminants if we are to explain the environmental distribution and fate of pollutants such as PCDD/Fs. (54 refs.
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| 7. |
- Persson, N. Johan, 1969-
(författare)
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Models of the Distribution of Persistent Organic Pollutants in the Marine Environment
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Persistent organic pollutants (POPs) is a group of chemicals that are toxic, undergo long-range transport and accumulate in biota. Due to their persistency the distribution and recirculation in the environment often continues for a long period of time. Thereby they appear virtually everywhere within the biosphere, and poses a toxic stress to living organisms. In this thesis, attempts are made to contribute to the understanding of factors that influence the distribution of POPs with focus on processes in the marine environment. The bioavailability and the spatial distribution are central topics for the environmental risk management of POPs. In order to study these topics, various field studies were undertaken. To determine the bioavailable fraction of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated naphthalenes (PCNs), and polychlorinated biphenyls (PCBs) the aqueous dissolved phase were sampled and analysed. In the same samples, we also measured how much of these POPs were associated with suspended particles. Different models, which predicted the phase distribution of these POPs, were then evaluated. It was found that important water characteristics, which influenced the solid-water phase distribution of POPs, were particulate organic matter (POM), particulate soot (PSC), and dissolved organic matter (DOM). The bioavailable dissolved POP-phase in the water was lower when these sorbing phases were present. Furthermore, sediments were sampled and the spatial distribution of the POPs was examined. The results showed that the concentration of PCDD/Fs, and PCNs were better described using PSC- than using POM-content of the sediment. In parallel with these field studies, we synthesized knowledge of the processes affecting the distribution of POPs in a multimedia mass balance model. This model predicted concentrations of PCDD/Fs throughout our study area, the Grenlandsfjords in Norway, within factors of ten. This makes the model capable to validate the effect of suitable remedial actions in order to decrease the exposure of these POPs to biota in the Grenlandsfjords which was the aim of the project. Also, to evaluate the influence of eutrophication on the marine occurrence PCB data from the US Musselwatch and Benthic Surveillance Programs are examined in this thesis. The dry weight based concentrations of PCB in bivalves were found to correlate positively to the organic matter content of nearby sediments, and organic matter based concentrations of PCB in sediments were negatively correlated to the organic matter content of the sediment.
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