Temporal and spatial trends of organohalogens in guillemot (Uria aalge) from North Western Europe

Abstract: The Arctic and sub-Arctic region of the North Atlantic is a remote area, also in relations to environmental contaminants, such as POPs, BFRs and last but not least, PFCs. Both the BFRs and PFCs are considered emerging pollutants of significant environmental concern.The main objective of this thesis is to increase the knowledge and understanding of organohalogen compound distribution in the Nordic environment, their occurrence in biota and change over time. The temporal change of environmental contaminants in the Baltic Sea was monitored over the years 1971 to 2001, with emphasis on BCPS. Further, the pollution profile of the Nordic region was investigated by using common guillemot eggs. Further, to investigate a single remote site, Iceland, in more depth, eggs from seven marine bird species were collected and analysed. Both the organohalogen compounds mentioned above and their metabolites were investigated. The study focused also on an inter-species difference in the bird’s capability of metabolising xenobiotics.All environmental pollutants investigated in the Baltic Sea show decreasing levels over the time period investigated. BCPS showed a remarkably small change over time compared to other compounds. These results reinforce the previous findings, indicating the North Atlantic as remote where the concentrations of the organohalogens are lower compared to Europe in general. There are some exceptions however; the concentration of HCB is ubiquitously distributed across the study area. Further, the spatial trends of the PFCs are complicated and differ within the PFC group. When comparing bird species from Iceland, the concentration of organohalogens mainly depends on trophic level, while migration seems to contribute to a lesser extent. There are some similarities in the metabolism between the bird species investigated. However, the guillemot seems to distinguish itself from other marine birds, with a different composition of metabolites, indicating a different metabolic capacity.In conclusion, even human populations living in remote areas need to minimise the release of pollutants to the environment. Long term, well organised, and extensive governmental monitoring programs are highly recommended to follow the quality the environment and to detect any immediate and/or new threats of chemical pollutants.