Change search
Refine search result
1 - 6 of 6
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Nfon, Erick
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Time trends, biomagnification and food web magnification of PCBs in the Baltic Sea2007Licentiate thesis, monograph (Other academic)
  • 2.
    Nfon, Erick
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Tools for Evaluating the Fate and Bioaccumulation of Organic Compounds in Aquatic Ecosystems2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The bioaccumulation of organic contaminants in aquatic ecosystems has been a key focus in environmental toxicology over the last decades. Bioaccumulation is a key concept in ecological risk assessments since it controls the internal dose of potential environmental contaminants. Information on the bioaccumulation of contaminants is used by regulatory authorities in the development of water quality standards, categorizing substances that are potential hazards and quantifying the risk of chemicals to human health. A basis for identifying priority chemicals has been the use of the octanol-water partition coefficient (KOW) as a criterion to estimate bioaccumulation potential. However, recognizing that the bioaccumulation process is not controlled by the hydrophobicity of a chemical alone, this thesis proposes a set of tools, incorporating chemical properties, environmental characteristics and physiological properties of organisms, to study the bioaccumulation of contaminants in aquatic ecosystems.

     In striving to achieve this objective, a tool based on an equilibrium lipid partitioning approach was used in Paper I to evaluate monitoring data for bioaccumulation of organic contaminants. In Papers II and III, mechanistic based modelling tools were developed to describe bioaccumulation of hydrophobic compounds in aquatic food webs. In Paper IV, the bioaccumulation of organic compounds in aquatic food chains was studied using stable isotopes of nitrogen. The mechanistic fate and food web models developed in this thesis provide regulators and chemical manufacturers with a means of communicating scientific information to the general public and readily applicable mechanistic fate and food web models that are easily modified for evaluative assessments purposes.

  • 3.
    Nfon, Erick
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Armitage, James
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Influence of submerged aquatic vegetation on the fate and food web transfer of pesticides in small freshwater ecosystems2009In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298Article in journal (Refereed)
    Abstract [en]

    A dynamic combined fate and food web model was developed to investigate the influence of macrophytes (submerged aquatic vegetation) on the fate and food web transfer of pesticides of varying chemical properties in small-scale ecosystems such as ponds, streams, ditches or mesocosms. The model results indicate that aquatic macrophytes have a significant effect on the fate and food web transfer of highly hydrophobic compounds with log KOW ≥ 5. Modelled peak concentrations in biota were highest for the scenarios assuming the lowest macrophytes biomass density. The distribution and food web transfer of compounds with log KOW ≤ 4, which is a more representative hydrophobicity of the majority of current-use pesticides, are not affected by the inclusion of aquatic macrophytes in the pond environment. The increased importance of macrophytes for the highly hydrophobic compounds is a result of the dominance of particle deposition in the mass transfer of organic compounds from water to macrophytes. It is recommended that the mechanistic model developed here be used as a tool for interpreting laboratory, mesocosm and field measurements as well as a possible higher-tier regulatory tool, especially for assessing the aquatic behaviour of pesticides with high KOW values.

  • 4.
    Nfon, Erick
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Modelling PCB bioaccumulation in a Baltic food web2007In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 148, p. 73-82Article in journal (Refereed)
  • 5.
    Nfon, Erick
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Interpreting time trends and biomagnification of PCBs in the Baltic region using the equilibrium lipid partitioning approach2006In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 144, p. 994-1000Article in journal (Refereed)
  • 6.
    Nfon, Erick
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Cousins, Ian T.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Broman, Dag
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Biomagnification of organic pollutants in benthic and pelagic marine food chains from the Baltic Sea2008In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 397, no 1-3, p. 190-204Article in journal (Refereed)
    Abstract [en]

    The trophic transfer of organic pollutants with varying physical chemical properties was determined in both a pelagic and benthic food chain using delta N-15 as a continuous variable for assessing trophic levels. The trophic transfer of organic pollutants through the entire food chain in terms of food chain magnification factors (FCMFs) was quantified from the slope of the regression between In [concentration] and delta N-15. Organic pollutants with statistically significant FCMFs >1 were considered to biomagnify within the food chain, whereas those with FCMFs < 1 were considered to trophically dilute. Statistically significant FCMFs >1 were found for PCB congeners and organochlorine pesticides in the Baltic food chains whereas statistically significant FCMFs <1 were found for PAHs and PCNs due to trophic dilution resulting from metabolism. FCMFs were generally greater in the pelagic food chain than in the benthic food chain. However, estimated FCMFs for the benthic food chain are likely in error, as the delta N-15 method suggested a food chain structure which was not consistent with the known dietary patterns of the species. Biomagnification factors (BMFs) were additionally calculated as the ratio of the lipid normalized concentrations in the predator and prey species with adjustment for trophic level and were generally consistent with the FCMFs with BMF >1 for PCBs and organochlorines.

1 - 6 of 6
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf