Old and new organic priority contaminants in Norwegian fjords: old sins or ongoing input? Passive samplers as novel tool to measure fluxes

In about 30 coastal zones in Norway, seafood consumption restrictions are in place because of elevated levels of POPs (Persistent Organic Pollutants). The discussion around potential cleanup in various coastal zones has thus far addressed the exposure fro m contaminated sediments. However, remediation measures can only be effective if ongoing emissions to the water system, mainly via air, incoming river water and sewage treatment plant water, are much smaller than the amounts released from sediments. Curre ntly no guidance document exists which contains any advice or methodologies on how the relative risk of environmental exposure from other sources (other than the sediment) can be evaluated and integrated into the decision making process, although the urge nt need for such information is clearly recognized. This project aims to address this crucial knowledge gap by further developing and evaluating methods to quantify contemporary contaminant pathways in coastal zones. In other words: the question arises w hether it is our sins from the past (i.e., sediment-bound chemicals) or current and ongoing emissions (new sins) that cause high POP levels in fjord waters and thus in marine organisms. To answer this question, we propose to employ a novel passive sampler technique (ultrathin polyoxymethylene) in sediment cores and in water and air column gradients to derive diffusive intermedia fluxes, and to compare these fluxes with relevant advective particle-mediated fluxes. The study area will be Oslofjorden, and th e POPs studied are the classic PAHs, PCBs and HCH as well as the emerging contaminant class brominated flame retardants (PBDEs). This proposal will provide answers to one of the aims of Havkyst subprogram I (Marine Ecosystems): ?What are driving forces an d physical/chemical processes that influence marine ecosystems?? In addition, a sharp tool will be developed that can be applied to many fjord systems in Norway where potential remediation is expected.