North Sea oil drilling operations employ oil-based muds which contain aromatic compounds likely to be genotoxins. Recent legislation has controlled use and discharge of the muds to try to minimise their effects. In an attempt to include a procedure in the ongoing monitoring programme in the North Sea, which could detect genotoxic effects, the sister chromatid exchange (SCE) technique has been developed in the plaice, <i>Pleuronectes platessa</i>. Preliminary work on the plaice involved developing the techniques for cytological examination and for obtaining sister chromatid differentiation. A standard technique using kidney tissue was adopted and is described and compared with that of other studies. SCE levels were measured after intra peritoneal (ip) injections of various substances in order to test the technique. Mitomycin C (MMC) commonly used as a positive control in genotoxicity studies, elicited a significant increase in SCEs when administered at 10^-4mg/g fish and resulted in mitotic inhibition at a dosage of 10^-3mg/g fish. Diesel oil and low toxicity base oil (used in drilling muds) were injected at 1.0ml/100g fish and the fish killed after periods of time. Diesel produced a peak in SCE level, almost significantly higher than control levels 7 days after injection. The low tox oil produced a significantly increased level of SCEs at 5 days after injection. Results are discussed in context of other similar studies. Environmental conditions were simulated in an experiment by exposing fish to sediments mixed with diesel and low tox oil based drilling cuttings to give sediments with theoretical oil concentrations of 5 and 50 ppm. Results show a slight but insignificant increase in SCE levels in fish exposed to sediments containing 50 ppm diesel. In a subsequent experiment fish were exposed to diesel based and different low tox oil based drilling muds in sediments, at theoretical oil concentrations of 30 ppm. No difference in SCE levels was found between any of the groups. Suggestions are put forward to explain these inconclusive results and problems encountered with the technique are discussed. A field sampling programme was carried out where plaice were collected from areas close to drilling installations in the North Sea and from control areas. SCE levels in both groups of fish were low and not significantly different. Sediment sample analysis showed that the control area was contaminated with oil, thus fish were probably exposed to higher levels of oil than in experiments. Results are discussed and an assessment of the use of the technique at sea was made. Results were analysed using analysis of variance (AOV) on transformed data, and by high SCE frequency analysis (HFC) (Carrano & Moore, 1982) in order to compare the sensitivity of the two methods. There was little difference in the sensitivity of the methods, and HFC analysis appears to have no advantage over the more established AOV. It was concluded that although the SCE technique was successfully developed in the plaice, several limitations were recognised and further studies are required before the assay could be used routinely in monitoring studies.

No description available.

No description available.

For the past several decades, industry has filled lagoons and landfills with significant quantities of polychlorinated biphenyls (PCBs). Other wastes such as carbon tetrachloride and various alcohols have mixed with PCBs. Soil columns spiked with Aroclor 1242 were leached with such solvents. Ninety-one days of deionized water flow did not move a detectable amount of Aroclor 1242 more than 2 cm. through soil columns. Sixty-nine days was sufficient time for an alcohol mixture to carry Aroclor 1242 over 7 cm, the soil depth of the column. Five days was sufficient time for carbon tetrachloride: ethanol to carry Aroclor 1242 the same distance. A mixture of organic solvents can promote mobility of lipophilic organics such as polychlorinated biphenyls in the soil when water alone would not be effective. While assessing the extent of a chemical spill or the contamination resulting from improper disposal, it is clear that the interactions of chemical contaminants must be considered. / Department of Natural Resources

Jag skall i mitt projekt först och främst få erfarenhet av hur det är att samarbeta som designer med ett företag och även få ut en produkt som är klar att använda och som skall kunna säljas i butiker runt om i landet. Den skall följa företagets riktlinjer, vara energisnål och vara funktionell men samtidigt tilltalande. / Produktdesign/Självständigt projektarbete – Examensarbete

There is no abstract available for this dissertation.

A posterior gill of the common shore crab Carcinus maenas (Crustacea:Decapoda) was used to study the effects of sublethal copper concentrations on gill morphometry, and gill cell ultrastructure and distribution. Primarily, the ultrastructure and distribution of gill cells in the untreated gill of crabs acclimated to 35‰ seawater were characterised. Gill ultrastructure was subsequently shown to vary markedly at 10‰ compared to 35‰ seawater. Ultrastructural and distributional, rather than gross morphological, change occurred in the gill following exposure to copper at each salinity. Ultrastructural studies showed that as the length of copper exposure increased the gill epithelial layer became highly vacuolated, the number of plasma membrane infoldings and mitochondria became reduced, the microtubular network became disrupted, the endoplasmic reticulum became swollen and the cell cytoplasm contained many free ribosomes. Copper exposure also resulted in an increase in the number of haemocytes in the gill, some of which became attached to the basal epithelial cell surface or actually infiltrated into the epithelial cell cytoplasm. Ultrastructural change was more extensive when copper was administered at 35‰ rather than 10‰ seawater. These effects are described and correlated with previously documented biochemical and physiological responses to heavy metals in crustaceans. In addition, the elemental composition of the gill granular haemocytes suggested they play an important role in the immobilisation and removal of copper-from the gill. This study has shown the way forward in creating a better understanding of the mechanisms behind heavy metal toxicity in marine organisms is the use of environmentally realistic concentrations of heavy metal administered in flow-through seawater systems.

Nearly thirty C20, C25, and C30 highly branched isoprenoid (HBI) hydrocarbons have been detected, sometimes in high concentrations, in recent freshwater, estuarine, coastal and hypersaline sediments, and water column particulate matter from numerous locations worldwide. The parent structures have been proved but only a few of the double bond positions have been established. The assignment of C21, C22 and C26 homologues and other C20 and C25 isomers, remains tentative. A wide body of evidence suggests that the compounds are biogenic in origin, with algae and possibly bacteria the most likely source organisms. A few of the compounds have been identified in field samples of algae but none have been reported in laboratory cultured biota. The alkenes with more than two double bonds appear to be rapidly removed from the hydrocarbon fraction in most sediments, whereas the alkanes and monoenes seem to be more resistant to biodegradation and hence occur in some more ancient sediments and oils. There is evidence that some of the alkenes react rapidly with sulphur to form either S-containing HBI heterocycles or become bound within macromolecular aggregates both found in sediments and some oils. The compounds, both as hydrocarbons and S-containing analogues, may prove useful environmental indicators once the sources and exact structures of more of them have been established. In the literature the structural elucidation of C25 and C30 alkenes has been based mainly on the analysis of their hydrogenation products. However, some authors concluded that the alkenes are cyclic since some could not be fully hydrogenated. The structure of a C25 HBI diene was proven to be a cyclic by hydrogenation studies and GC and GCMS analyses which showed the HBI compound to be fully saturated. The isolation and characterisation of synthetic alkenes resulted in the assignment, or partial assignment, of structures to four C20, six C25 and four C30 monoenes. The formation of novel monoenes via isomerisation reactions has also been achieved. The compounds form a valuable database of chromatographic and spectroscopic information for the assignment of sedimentary alkenes but the importance of isolation and micro-ozonolysis has been emphasised. Synthetic HBI alkenes were used to assign structures and partial structures to naturally occurring HBI hydrocarbons in three sediments. Other monoenes (both with methylene double bonds) were isolated from the sediments and characterised using spectroscopic and micro-ozonolysis data. The widespread occurrence of C20 and C23 HBI hydrocarbons in Tamar sediments and associated algae (macrophytes and diatoms), the large variation in isotopic composition evident for the C20 monoene, and the seasonal sedimentary distribution all suggest two possible sources for the HBI hydrocarbons; microalgae and/or heterotrophic bacteria. Investigation of the distribution of hydrocarbons from the Peru upwelling area confirmed the rapid decrease in concentration of C25 HBI alkenes with depth. A mixture of HBI monoenes was successfully incorporated into melanoidins but not detected in the humic acid pyrolysate which implied that incorporation of HBI alkenes into accreting humic substances was not a major mechanism of diagenesis of HBI alkenes. This study has extended present knowledge of the structures of HBI monoenes and has suggested two possible biological sources. There is still much to be learned about HBI polyenes and the subject is proving to be a fruitful area for further research into biomarker potential. Some possible future approaches are suggested.

Three immobilization matrices, Biofix (kaolinite microspheres), Drizit (polypropylene fibres) and polyester polyurethane were used as substrata for use in bioremediation. Enhanced biodegradation of petrol (Slovene diesel) and Ekofisk crude oil occurred with immobilization of Pseudomonas fluorescens to Biofix and Drizit in freshwater and saltwater systems. When compared to free bacteria, immobilization resulted in; increased growth, accelerated ability of the cells to utilize oil, and enhanced biodegradation as determined by gas chromatography. In the freshwater systems Drizit immobilized cells reduced the lag phase to one day in comparison to six in a free system and increased biodegradation of the n-alkanes by 67 %. Immobilization resulted in enhanced production of a rhamnolipid biosurfactant over the first three days of incubation in comparison to free living bacteria which showed a lag phase of two days. All three supports were compared by; scanning electron microscopy, cell loading capacity, absorption of oil, their abilities to enhance oil biodegradation and the effect of drying and storage on the immobilized cells. Biodegradation of hydrocarbons by immobilized cells was dependent on the biocarrier, with polyurethane immobilized cells failing to enhance biodegradation of Ekofisk crude oil. Drizit was the most effective biocarrier tested and the most suitable immobilization substratum for use as a bioremediation agent. Investigation into the location of the genes for alkane degradation in immobilized Pseudomonas fluorescens was undertaken. Plasmid DNA was detected using gel electrophoresis, and caesium chloride-ethidium bromide gradient was carried out to confirm the presence of the plasmid, but no plasmid band was visualized. The successful immobilization system was scaled-up, optimized by supplementation with nitrates and phosphates and applied to microcosms that modelled environmental conditions. Enhanced biodegradation of Ekofisk crude oil was demonstrated on a larger scale, in an estuarine microcosm, with the immobilized systems showing an average degradation of 41.9 % in comparison to 7.1 % in the microcosm containing free indigenous bacteria.

Observational and experimental studies have been undertaken in the southern North Sea environment, including five major estuaries (Humber, Thames, Scheldt, Weser and Elbe), with the aim of elucidating the mechanistic and kinetic details of trace metal reactivity required for the refinement of pollutant transport models. The results of a systematic investigation of suspended particle characteristics (BET specific surface area and porosity, carbon content. Fe and Mn oxide coatings) indicated that, although there exists significant yet explicable variability among the North Sea estuaries, such compositional factors do not exert an observable influence on solid-solution interactions. Furthermore, chemical reactivity was not usually demonstrable from observations of leachable particulate trace metals as phase interactions Impart relatively little influence on their concentrations; particulate metal distributions therefore generally conformed with mixing of fluvial and marine material unless perturbed by major anthropogenic sources as in the Humber. Solid-solution redistributions were revealed by following the partitioning of artificial radiotracers in a series of carefully controlled experiments in which salinity and suspended solids concentration gradients were simulated by mixing river and sea water end-member samples. Relationships between salinity and the solid:solution concentration of radiotracers as quantified by a distribution coefficient ( K Q ) indicated substantial desorption from particles of ^^®Cd and ^"^^Cs. conservative behaviour of ^ ^ Z n , and oxidative removal from solution of ^^Mn. Radiochemical techniques applied in situ to study solid-solution partitioning in the southern North Sea established a more significant role of particle composition (in particular, estuarine-derived versus plankton-rich material) in regulating trace metal behaviour in offshore waters. This finding was corroborated by distinct seasonal contrasts in measured particulate metal concentrations; whereas most metals (Fe, Mn. Cu, Pb, Zn) were enriched during winter when detrital and terrigenous components from fluvial/resuspension inputs dominate. Cd was elevated during summer in tandem with amplification of the biomass. These results provide a valuable basis for both future long-term pollutant monitoring programmes, and the conceptual development of estuarine chemical flux models, specifically the incipient Plymouth Marine Laboratory model of the Humber plume.