| 1. |
- Berglund, Olof, et al.
(author)
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Influence of trophic status on PCB distribution in lake sediments and biota
- 2001
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In: Environmental Pollution. - 0269-7491. ; 113:2, s. 199-210
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Journal article (peer-reviewed)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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| 2. |
- Berglund, Olof, et al.
(author)
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The effect of lake trophy on lipid content and PCB concentrations in planktonic food webs
- 2001
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In: Ecology. - 0012-9658. ; 82:4, s. 1078-1088
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Journal article (peer-reviewed)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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| 3. |
- Björn van Praagh, Helena, et al.
(author)
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Metabolic fate of C-14-labelled chlorinated and non-chlorinated fatty acids in goldfish (Carassius auratus)
- 2004
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In: Fish Physiology & Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 30:1, s. 13-20
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Journal article (peer-reviewed)abstract
- In order to study the metabolic fate of chlorinated fatty acids in fish, goldfish were fed either 9,10-dichlorostearic acid or oleic acid, chosen as the unchlorinated analogue, both radiolabelled at either the carboxyl (1st) or the terminal (18th) carbon of the fatty acid chain. By keeping the fish in hermetically closed aquaria, all the respired, assimilated and excreted radioactivity could be accounted for. Fish fed 9,10-dichlorostearic acid labelled in the terminal end respired radioactive CO2 to a much lower degree than fish fed the other test compounds. As a consequence, the radioactivity bound in lipids was higher in the group of fish fed dichlorostearic acid labelled in the terminal end. It is suggested that the chlorine atoms in the middle of the carbon chain obstruct the metabolic turn-over of 9,10-dichlorostearic acid, which may have an impact on the residence time of these compounds in the ecosystem.
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| 4. |
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| 5. |
- Enell, Anja, et al.
(author)
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A column method for determination of leaching of polycyclic aromatic hydrocarbons from aged contaminated soil
- 2004
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In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 54:6, s. 707-715
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Journal article (peer-reviewed)abstract
- In this study a column leaching method for investigation of hydrophobic organic contaminants (HOCs) leaching from soil was developed. The method set-up is based on a recycled flow of sterile water through a soil column with a sedimentation chamber mounted on top of the column, in connection with on-line filtration. The combination of a sedimentation chamber and an on-line filtration enables the measurement of leaching concentrations from contaminated materials consisting of very fine particle fractions. In addition, by using on-line solid phase extraction, minute amounts of leaching HOCs may be captured and quantified with high accuracy and reproducibility. The method was applied successfully on a contaminated aged soil sample and the leaching behavior of seven PAHs, with three to six aromatic rings, was monitored for more than 1600 h under saturated conditions. The tested PAHs were fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)pyrene and benzo(ghi)peryiene. The method proved to be reliable and capable of providing data on leachable amounts of the PAHs under field-like conditions and over a longer period of time. The results indicated low availability of the studied contaminants since only a minor fraction (0.3%) of the initial amount of PAHs in the soil was removed during the experiment (liquid/solid-ratio of 700 l/kg). Thus PAHs in aged contaminated soil are not to be expected to be released to any great extent only by leaching with water. (C) 2003 Elsevier Ltd. All rights reserved.
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| 6. |
- Enell, Anja, et al.
(author)
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Desorption kinetics studies on PAH-contaminated soil under varying temperatures
- 2005
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In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 61:10, s. 1529-1538
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Journal article (peer-reviewed)abstract
- The purpose of this study was to investigate the effect of temperature on the release of polycyclic aromatic hydrocarbons (PAHs) from aged contaminated soil. The release of fluorene, phenanthrene, anthracene, fluoranthene and pyrene at 7, 15, 18 and 23 °C was studied using a column leaching method with a hydraulic retention time of 0.5 h. As the temperature declined from 23 to 7 °C the concentrations decreased by a factor of 11–12 for all the studied compounds except for anthracene, which only decreased by a factor 7. Rate constants at maximum release rate at the four studied temperatures were assessed. From temperature dependence studies, apparent activation energies of desorption, , were calculated. -values appeared to be in the range of 105–137 kJ mol−1 for the studied PAHs and increased with the LeBas molar volume of the compounds. The increase of with increased molecular size indicates stronger sorption with increased hydrophobicity of the compounds.
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| 7. |
- Ewald, Göran, et al.
(author)
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Biotransport of organic pollutants to an inland Alaska Lake by migrating Sockeye Salmon (Oncorhynchus nerka)
- 1998
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In: Arctic. - 0004-0843. ; 51:1, s. 40-47
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Journal article (peer-reviewed)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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| 8. |
- Ewald, Göran, et al.
(author)
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Modellering som pedagogisk metod
- 2005
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In: [Host publication title missing].
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Conference paper (peer-reviewed)abstract
- Att hantera och använda sig av modellerings- och simuleringsverktyg är inte enbart något som en majoritet av våra studenter får stor nytta av i sitt framtida yrkesliv. Det är också användbara pedagogiska verktyg för att nå insikt i hur olika system fungerar, hur vi subjektivt uppfattar att systemen fungerar och även att kommunicera denna uppfattning. I vår undervisning inom Lund University Master’s Programme in International Environmental Science (LUMES) är metoder som “causal loop diagram” och annan “mind mapping” viktiga verktyg för att få studenter med vitt skilda akademiska och kulturella bakgrunder att kommunicera på ett effektivt sätt. Studenterna tvingas även ifrågasätta sina egna värderingar då metoderna förutsätter att de tar klar ställning till hur ett system fungerar. Även för “rena” tekniker/naturvetare har jag funnit att en djupare förståelse för vissa, ofta relativt enkla fenomen och processer, t.ex. kemisk jämvikt, bioackumulation av miljögifter, snabbt och effektivt kan förmedlas med hjälp av att använda modelleringsövningar i undervisningen. Vi jämför de olika studentkategorienas utgångspunkter för att konstruera modeller och visar hur modellering kan användas för olika syften i undervisningen.
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| 9. |
- Ewald, Göran
(author)
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Role of Lipids in the fate of organochlorine compounds in Aquatic Ecosystems
- 1996
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Doctoral thesis (other academic/artistic)abstract
- Both results of laboratory experiments and material collected in the field have shown the lipid composition in organisms to have a significant effect on the bioaccumulation of pollutants and on the lipid steady-state concentrations of pollutants there. The redistribution of persistent organic pollutants which occurs in organisms as a consequence of the depletion of lipid depot, was studied in a population of migrating Pacific salmon (Oncorhynchus nerka). Concominant with an increase in lipid pollutant concentration during their river ascent, pollutants were shown to be redistributed from the muscle tissue to the lipid-rich gonads of the salmon Furthermore, the lipids were found to act as compartments for pollutant transportation, the salmon bringing pollutants to their spawning lake. Such 2biotransport2 can significantly influenced the pollutant levels in the biota of the spawning lake. This highlighted one route for pollutant transfer between ecosystems. In the assessment of lipid-pollutant interactions, the analytical methods employed are of great importance. Efficiency in extracting both total lipids and organic pollutants of varying lipophilicity from the fish muscle was shown to be related to the lipid composition of the sample in question. This reduces the comparability of results obtained by different extraction methods and from different species. A further ecotoxicological aspect of lipids that was discussed concerns altered lipids containing organic pollutants, specifically chlorinated fatty acids. These cause toxic effects and diverge from other anthropogenic organic pollutants in that responses of the organism aimed at excretion of them appeare not to occure. Such chlorinated fatty acids are incorporated into complex lipids within the organism and may be transferred then within the food-chain. They are suggested as being 2biologically stable2 pollutants. Based on the results presented in this thesis I conclude that lipids have a strong influence on the distribution of lipophilic organic pollutants at every level of organisation in an ecosystem and that they should be of major concern in analytical work and in data evaluation within ecotoxicology.
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| 10. |
- Isaksson, Karolina, et al.
(author)
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Hållbar stadsutveckling i praktiken – färdplan för kollektivtrafik i samhällsplanering
- 2014
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Reports (other academic/artistic)abstract
- Forum för innovation i transportsektorn har initierat ett arbete med färdplaner inom områden som är av strategisk vikt för att ställa om till ett hållbart transportsystem med radikalt minskad miljö- och klimatpåverkan. I detta sammanhang är kollektivtrafik en central fråga. Det finns redan mycketkunskap som visar betydelsen av att planera samhället och den fysiska bebyggelsen på ett sätt som stimulerar till en yt- och energieffektiva transporter. Men trots all kunskap är bilen fortfarande ofta norm i nationell, regional och lokal transportpolitik och planering. En nyckelfråga för att skapa ett transportsystem som kan bidra till att förverkliga hållbara och attraktiva städer och regioner handlar om att göra kollektivtrafik och andra hållbara färdmedel tillgrundprinciper i samhällsplaneringen. Under hösten 2013 fick K2 och SKL uppdraget att leda ett arbete med fokus på denna fråga. Uppdraget grundades i ”Färdplan för kollektivtrafikens roll i en hållbar samhällsutveckling” som Svensk kollektivtrafik och K2 hade tagit fram gemensamt undervåren 2013. I arbetet med denna färdplan har vi haft hjälp av en bred konstellation av personer med kompetenser inom till exempel fysisk planering, kollektivtrafik, byggindustrin, handel, hållbar design och fastighetssektorn. Mot bakgrund i befintlig forskning och resultat från workshopar har färdplanentagits fram. De frågor som varit vägledande för vårt arbete är potentialen i en mer kollektivtrafikanpassad samhällsplanering och vilka insatser och aktiviteter som är viktigast för att på kort tid komma framåt i denna fråga.Arbetet har genomförts under perioden november 2013 till oktober 2014. Vi vill rikta ett varmt tack till alla som på något sätt har bidragit till arbetet. En förteckning över dessa personer återfinns i bilaga 3. Färdplanen utmynnar i förslag på ett antal konkreta insatser som bör prioriteras här och nu för attkomma vidare i arbetet för ett transportsystem med minskad miljö- och klimatpåverkan, som kan bidra substantiellt i förverkligandet av hållbara och attraktiva städer och regioner.
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