MILJØ2015-Norsk miljøforskning mot 2015

The project is concerned in better establishing whether there are chemicals present in the Norwegian environment that may pose a risk that is not currently understood. The approach being used is to use biological tests specific to different types of toxic ity to first establish the presence of such chemicals in the environment and then couple this with advanced chemical analysis to identify which chemicals are responsible for the effects we see in these tests. To date we have focused on chemicals that have dioxin-like toxicity in samples of snow, mosses and leaves and polar bear blood. The tests show that dioxin-like chemicals are present in all of the different types of samples that we collected; snow from Oslo and Norefjell, mosses from Oslo, Norefjell a nd Harangervidda, and polar bear blood plasma (archived). Isolation of the dioxin-like compounds from road-side snow shows that there are undetectable levels of traditional dioxins and furans whilst complex mixtures of polycyclic aromatic compounds (PAC) are responsible for the effects seen. The likely source of these PAC is oil and its combustion. Much of this complex mixture of PAC and laboratory evaluation suggests that only a small amount of this complex mixture of PAC is present in a bioavailable for m. No polychlorinated dibenzodioxins and dibenzofurans or polychlorinated biphenyls were detected in the samples; the occurrence of PAHs, however, explained up to 9 % of the AhR agonist activity in the samples, whilst comprehensive two-dimensional gas chr omatography coupled to mass spectrometry (GCxGCToF-Ms) identified PAH derivatives such as polycyclic aromatic ketones and alkylated, nitrogen sulphur and oxygen PAHs in the particle fractions. The (large) discrepancy between the total and explained activi ty highlights the fact that there are other as yet unidentified AhR agonists present in the environment (Muusse et al., 2012). With regards the moss samples, much of the reporting period has been spent on developing multivariate statistical tools in orde r to help elucidate which are the key toxicants in the moss samples analysed. Work on characterizing dioxin-like contaminants in polar bear plasma samples will not continue due to similar work being completed in Denmark. Further work on dioxin-like compou nds has focused on seagull eggs that have been collected in spring 2012 from Vestfold and Finnmark. The characterization will be based on the same approach used for the other samples with TEQCALUX from 16 to 401 pg TEQ/g lw in the samples from the north and between 6 and 360 pg TEQ/g lw in the south eastern samples (Muusse, In press). High resolution MS analysis will be used to identify the compounds responsible for these effects. Biologically active compounds can enter the environment from both man-ma de and natural sources. One example is leaf-litter that covers a large part of Norway every autumn. For example, we have shown that aqueous extracts of birch and pine leaves contain compounds that block the androgen receptor, whilst extracts from oak leav es contain compounds that block the estrogen receptor. Compounds found in leaves, and possibly other plants, are therefore capable of interfering with the binding of estrogens and androgens to their respective receptors. This may have important consequenc es on our understanding of environmental endocrine disruption. Further work will focus on identifying these compounds in the leaf extracts using high resolution mass spectrometry.

Identifying new environmental pollutants is one of the greatest challenges that faces environmental scientists. This proposal will develop and apply advanced effects-directed analysis (EDA) techniques that will integrate modern quantitative receptor based reporter assays with advanced analytical chemistry, to identify emerging substances in samples collected from the Norwegian environment. Through the development of an internationally renowned group of scientists an unique learning environment has been cr eated for a PhD candidate whom will develop and apply the techniques. Samples from the Artic, upland areas and Norways largest lake will be first screened using receptor based in vitro assays and EDA used to identify the compounds responsible. The output will be a list of emerging substances known to occur in the Norwegian environment and have specific ecotoxicological effects (Estrogeniic, anti-estrogenic, androgenic, anti-androgenic, thyroid hormone receptor agonists and antagonists, antibiotic and diox in-like toxic effects). The output will be of outstanding value to monitoring authorities and the environmental science community at large.