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| 2. |
- Agrell, Cecilia, et al.
(författare)
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Evidence of Latitudinal Fractionation of Polychlorinated Biphenyl Congeners along the Baltic Sea Region
- 1999
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 33:8, s. 1149-1156
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Tidskriftsartikel (refereegranskat)abstract
- Annual cycles of the atmospheric concentrations of PCBs were determined at 16 (mostly rural) stations around the Baltic Sea between 1990 and 1993. The concentration levels of individual congeners were found to be influenced by their physical-chemical properties, ambient temperature, and geographical location. Median levels of PCBs were similar at all stations except at one urban site near Riga. A latitudinal gradient with higher levels in the south was found for the sum of PCB as well as for individual congeners, and the gradient was more pronounced for the low volatility congeners. As a result, the high volatility congeners increased in relative importance with latitude. Generally, PCB concentrations increased with temperature, but slopes of the partial pressure in air versus reciprocal temperature were different between congeners and between stations. In general, the low volatility congeners were more temperature dependent than the high volatility PCB congeners. Steep slopes at a sampling location indicate that the concentration in air is largely determined by diffusive exchange with soils. Lack of a temperature dependence may be due to the influence of long-range transported air masses at remote sites and due to the episodic or random nature of PCB sources at urban sites.
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| 3. |
- Agrell, Cecilia, et al.
(författare)
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PCB congeners in precipitation, wash out ratios and depositional fluxes within the Baltic Sea region, Europe
- 2002
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Ingår i: Atmospheric Environment. - 1352-2310. ; 36:2, s. 371-383
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Tidskriftsartikel (refereegranskat)abstract
- Concentrations of PCB congeners were determined in precipitation and the annual and seasonal depositional fluxes were calculated for 16 (mostly rural) stations around the Baltic Sea during 1990-1993. The concentrations of individual congeners in precipitation were found to be influenced by atmospheric concentrations of PCBs, ambient temperature, precipitation volume and physico-chemical properties of the compounds. Median levels of PCBs in precipitation differed one order of magnitude between stations. When analyzing all data together to obtain regional trends, concentrations of PCBs in precipitation decreased with increasing temperature. This relationship was the same for all stations but differed in the magnitude of the slope for individual congeners. Low chlorinated PCB congeners showed steeper slopes for the temperature relationship than did high chlorinated congeners, a result explained by high atmospheric concentrations of the low chlorinated congeners during low temperatures. Annual wash out ratios were between 31 and 72 x 103 and tended to be higher for the high chlorinated congeners. Wash out ratios decreased with increasing temperature for all congeners except PCB-33. At snow scavenging events, the wash out ratio of PCBs increased with a factor of 2. Latitudinal trends for PCB concentrations in precipitation and deposition were generally not statistically significant. The calculated yearly deposition of PCBs to the Baltic Sea was 390 and 5-18 kg for individual congeners, with PCB-138 having the highest flux. Deposition of PCB congeners varied seasonally, with a factor between 2 and 3, and was generally highest during fall. Relatively higher deposition of low chlorinated congeners compared to high chlorinated congeners was found during winter. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 4. |
- Backe, Cecilia, et al.
(författare)
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Polychlorinated biphenyls in the air of southern Sweden - spatial and temporal variation
- 2000
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Ingår i: Atmospheric Environment. - 1352-2310. ; 34:9, s. 1481-1486
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Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated biphenyls in the lower atmosphere were studied over a regional area covering approximately 11000 km(2) in southern Sweden. Sampling were performed in 1992-1993, continuously during one year, where samples from 11 sampling-sites (in all 260 samples) were analysed. PCB concentrations ranged over two order of magnitudes, 7-983 pg m(-3). Differences in PCB concentrations among the sampling sites revealed a large number of high-concentration outliers, mainly originating from one suburban site. Smaller differences in PCB concentrations between sites probably originated from varying geographical and meteorological conditions, that affected exchange processes between air and surfaces differently at the sampling sites. (C) 2000 Elsevier Science Ltd. All rights reserved.
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| 5. |
- Berglund, Olof, et al.
(författare)
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Factors influencing organochlorine uptake in age-0 brown trout (Salmo trutta) in lotic environments
- 1997
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Ingår i: Canadian Journal of Fisheries and Aquatic Sciences. - 1205-7533. ; 54:12, s. 2767-2774
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Tidskriftsartikel (refereegranskat)abstract
- In 1994 and 1995, we investigated the relationship between stream morphology and water chemistry and levels of organochlorines (HCB, PCB, and DDT) in young-of-the-year brown trout (Salmo trutta) from 25 streams in southern Sweden. Contrary to earlier findings for lakes, we found a positive relationship between trophic status (total phosphorus) and uptake of persistent pollutants in stream biota (trout). This difference between benthic, stream environments and pelagic, lake environments may be related to processes affecting pollutant uptake, i.e., pollutant "spiralling" or the shift from heterotrophy to autotrophy in streams. Land use in the catchment area of the streams also affected pollutant levels in trout, with higher levels in agricultural landscapes and lower levels in forested areas. Size of catchment area, however, did not influence uptake of pollutants in trout. The results indicate that eutrophication of streams by agricultural activities and excessive nutrient loading may increase uptake of persistent pollutants in stream biota.
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| 6. |
- Berglund, Olof, et al.
(författare)
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Influence of trophic status on PCB distribution in lake sediments and biota
- 2001
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Ingår i: Environmental Pollution. - 0269-7491. ; 113:2, s. 199-210
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the relationship between trophic status and polychlorinated biphenyl (PCB) distribution in 19 Swedish lakes. We analyzed PCB in water, phytoplankton, zooplankton, fish and sediment during two sampling periods, in spring and summer. The mass of Sigma PCB in the lake sediments was positively related to lake trophy, i.e. more PCBs were accumulated and buried in the sediment of eutrophic lakes than in oligotrophic lakes. In the oligotrophic lakes a greater fraction of the total PCB load was dissolved in water. We conclude that this is a result of higher sedimentation rates in eutrophic lakes and relatively lower turnover of organic carbon in the water column of the shallow, eutrophic lakes. In the stratified lakes, the amount of PCB per cubic meter in the epilimnion decreased from spring to summer. We suggest that sedimentation of plankton beneath the thermocline during stratification act as a sink process of PCBs from the epilimnion
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| 7. |
- Berglund, Olof, et al.
(författare)
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The effect of lake trophy on lipid content and PCB concentrations in planktonic food webs
- 2001
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Ingår i: Ecology. - 0012-9658. ; 82:4, s. 1078-1088
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the influence of trophic status on the lipid content and polychlorinated biphenyl (PCB) concentrations in planktonic food webs from 19 lakes in southern Sweden. The lipid content in phytoplankton (10-45 mum), microzooplankton (45-150 mum) and large macrozooplankton (>500 mum) was negatively related to the total phosphorus (Tot-P) concentration in lakes. The lipid content in macrozooplankton (>150 Gem) and young-of-the-year roach (Rutilus rutilus) was not related to Tot-P in lakes. On a dry mass basis (ng/g dry mass), the sum of PCB concentrations in phytoplankton and microzooplankton was negatively related to Tot-P in lakes. Thus, the PCB concentrations in phytoplankton and microzooplankton were explained by the decreasing lipid content of these fractions with increasing trophic status of lakes; and when normalized to lipid content (ng/g extractable lipid) we found no differences in PCB concentrations among lakes. We conclude that the lipid content of phytoplankton increased with increased nutrient stress, explaining the negative relationship between lake trophy and phytoplankton organochlorine (OC) concentrations on a dry mass basis. The relationship found between lipids and lake trophy in producers was not transferred in the food chain.
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| 8. |
- Bremle, Gudrun, et al.
(författare)
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PCB in water and sediment of a lake after remediation of contaminated sediment
- 1998
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Ingår i: Ambio: a Journal of Human Environment. - 0044-7447. ; 27:5, s. 398-403
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Tidskriftsartikel (refereegranskat)abstract
- PCB concentration in river water at the outlet of a lake was monitored far two years following the completed remediation of the PCB contaminated sediment of the lake. The remediation resulted in lowered PCB concentration in the sediment, from 5 mu g g(-1) (d.w.) to 0.060 mu g g(-1) (d.w.). PCB concentration in the water decreased over the two years, but varied seasonally. Highest PCB concentrations were recorded in summer. PCB concentration was positively correlated to temperature. Spring and winter values of PCB concentration were positively correlated to water discharge and to suspended matter probably originating from resedimented particles during remediation, PCA analysis of congener patterns in the water supported this conclusion. The seasonality in PCB concentration and congener distribution seemed to gradually become similar to a location upstream of the contaminated lake.
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| 9. |
- Bremle, Gudrun, et al.
(författare)
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Uptake of PCBs in fish in a contaminated river system: Bioconcentration factors measured in the field
- 1995
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 29, s. 2010-2015
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Tidskriftsartikel (refereegranskat)abstract
- We have studied PCB concentration and domain (one to three congeners) distribution in water and fish along a gradient of a contaminated river system. The river was contaminated by a small lake that contains about 400 kg of PCB in the sediment. The PCB concentration in water in the outlet from the lake was 8.6 ng/L, which was 12 times higher than upstream. PCB concentration in fish from the lake was about 20 times higher than the concentration in fish from upstream lakes. The polluted lake considerably influenced domain distribution in both water and fish. The fish bioconcentration factors (BCFs) for low to highly chlorinated domains showed a bell-shaped curve. BCFs for low chlorinated PCBs were less than for more highly chlorinated ones, but for the largest molecules the BCFs were reduced. The bell-shaped curve remained also when domain numbers were transformed into corresponding log K-OW values. BCFs for the same domains were shown to vary between stations.
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| 10. |
- Ewald, Göran, et al.
(författare)
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Biotransport of organic pollutants to an inland Alaska Lake by migrating Sockeye Salmon (Oncorhynchus nerka)
- 1998
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Ingår i: Arctic. - 0004-0843. ; 51:1, s. 40-47
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants such as polychlorinated biphenyls (PCBs) and the pesticide DDT, known to harm wildlife, have been shown to reach pristine Subarctic and Arctic areas by global atmospheric transport. Another transport route for pollutant entry into these ecosystems is provided by migrating salmon. Pollutant transport was studied in a population of sockeye salmon (Oncorhynchus nerka) in the Copper River, Alaska during their 410 km spawning migration. Pollutants accumulated by the salmon during their ocean life stage were not eliminated during migration, but were transported to the spawning lakes and accumulated in the freshwater food web there. The influence of the biotransported pollutants was investigated by comparing pollutant levels and compositions in atmospheric deposition as well as in two different populations of arctic grayling (Thymallus arcticus). One grayling population was in the salmon spawning lake and the other in a nearby lake not hosting anadromous fish, but receiving pollutants only via atmospheric deposition. The grayling in the salmon spawning lake were found to have concentrations of organic pollutants more than two times higher than those of the grayling in the salmon-free lake, and the pollutant composition resembled that found in salmon. Thus, in the studied Alaska river system, biotransport was found to have a far greater influence than atmospheric input on the PCB and DDT levels in lake biota.
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