Sigurd Øxnevad

Environmental occurrence and risk of organic UV filters and stabilizers in multiple matrices in Norway

Eight organic UV filters and stabilizers were quantitatively determined in wastewater sludge and effluent, landfill leachate, sediments, and marine and freshwater biota. Crab, prawn and cod from Oslofjord, and perch, whitefish and burbot from Lake Mjøsa were selected in order to evaluate the potential for trophic accumulation. All of the cod livers analysed were contaminated with at least 1 UV filter, and a maximum concentration of almost 12 μg/g wet weight for octocrylene (OC) was measured in one individual. 80% of the cod livers contained OC, and approximately 50% of cod liver and prawn samples contained benzophenone (BP3). Lower concentrations and detection frequencies were observed in freshwater species and the data of most interest is the 4 individual whitefish that contained both BP3 and ethylhexylmethoxycinnamate (EHMC) with maximum concentrations of almost 200 ng/g wet weight. The data shows a difference in the loads of UV filters entering receiving water dependent on the extent of wastewater treatment. Primary screening alone is insufficient for the removal of selected UV filters (BP3, Padimate, EHMC, OC, UV-234, UV-327, UV-328, UV-329). Likely due in part to the hydrophobic nature of the majority of the UV filters studied, particulate loading and organic carbon content appear to be related to concentrations of UV filters in landfill leachate and an order of magnitude difference in these parameters correlates with an order of magnitude difference in the effluent concentrations of selected UV filters (Fig. 2). From the data, it is possible that under certain low flow conditions selected organic UV filters may pose a risk to surface waters but under the present conditions the risk is low, but some UV filters will potentially accumulate through the trophic food chain.

Do Antiparasitic Medicines Used in Aquaculture Pose a Risk to the Norwegian Aquatic Environment

Aquaculture production is an important industry in many countries and there has been a growth in the use of medicines to ensure the health and cost effectiveness of the industry. This study focused on the inputs of sea lice medication to the marine environment. Diflubenzuron, teflubenzuron, emamectin benzoate, cypermethrin, and deltamethrin were measured in water, sediment, and biota samples in the vicinity of five aquaculture locations along the Norwegian coast. Deltamethrin and cypermethrin were not detected above the limits of detection in any samples. Diflubenzuron, teflubenzuron, and emamectin benzoate were detected, and the data was compared the UK Environmental Quality Standards. The concentrations of emamectin benzoate detected in sediments exceed the environmental quality standard (EQS) on 5 occasions in this study. The EQS for teflubenzuron in sediment was exceeded in 67% of the samples and exceeded for diflubenzuron in 40% of the water samples collected. A crude assessment of the concentrations detected in the shrimp collected from one location and the levels at which chronic effects are seen in shrimp would suggest that there is a potential risk to shrimp. It would also be reasonable to extrapolate this to any species that undergoes moulting during its life cycle.

In vivo bioaccumulation of contaminants from historically polluted sediments - relation to bioavailability estimates.

Many contaminants are recalcitrant against degradation. Therefore, when primary sources have been discontinued, contaminated sediments often function as important secondary pollution sources. Since the management and potential remediation of contaminated marine sediments may be very costly, it is important that the environmental risks of contaminants present in these sediments and benefits of remediation are evaluated as accurately as possible. The objective of this study was to evaluate the bioavailability of common organochlorine contaminants and polycyclic aromatic hydrocarbons (PAHs) in selected polluted sediments from Norway by simple generic sorption models (free energy relationships), as well as by pore water concentration measurements. Furthermore, the aim was to predict bioaccumulation from these bioavailability estimates for comparison with in vivo bioaccumulation assessments using ragworm (Nereis virens) and netted dogwhelk (Hinia reticulata). Predicted biota-to-sediment accumulation factors (BSAFs) derived from pore water concentration estimates were in better agreement with the bioaccumulation observed in the test organisms, than the generic BSAFs expected based on linear sorption models. The results therefore support that site-specific evaluations of bioaccumulation provide useful information for more accurate risk assessments. A need for increased knowledge of the specific characteristics of benthic organisms, which may influence the exposure, uptake and elimination of contaminants, is however emphasized.

Bioaccumulation and trophic transfer of cyclic volatile methylsiloxanes (cVMS) in the aquatic marine food webs of the Oslofjord, Norway

The trophic transfer of cyclic methylsiloxanes (cVMS) in aquatic ecosystems is an important criterion for assessing bioaccumulation and ecological risk. Bioaccumulation and trophic transfer of cVMS, specifically octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), were evaluated for the marine food webs of the Inner and Outer Oslofjord, Norway. The sampled food webs included zooplankton, benthic macroinvertebrates, shellfish, and finfish species. Zooplankton, benthic macroinvertebrates, and shellfish occupied the lowest trophic levels (TL ≈2 to 3); northern shrimp (Pandalus borealis) and Atlantic herring (Clupea harengus) occupied the middle trophic levels (TL ≈3 to 4), and Atlantic cod (Gadus morhua) occupied the highest tropic level (TL>4.0). Trophic dynamics in the Oslofjord were best described as a compressed food web defined by demersal and pelagic components that were confounded by a diversity in prey organisms and feeding relationships. Lipid-normalized concentrations of D4, D5, and D6 were greatest in the lowest trophic levels and significantly decreased up the food web, with the lowest concentrations being observed in the highest trophic level species. Trophic magnification factors (TMF) for D4, D5, and D6 were <1.0 (range 0.3 to 0.9) and were consistent between the Inner and Outer Oslofjord, indicating that exposure did not impact TMF across the marine food web. There was no evidence to suggest biomagnification of cVMS in the Oslofjord. Rather, results indicated that trophic dilution of cVMS, not trophic magnification, occurred across the sampled food webs.

Petroleum oil and mercury pollution from shipwrecks in Norwegian coastal waters

Worldwide there are tens of thousands of sunken shipwrecks lying on the coastal seabed. These potentially polluting wrecks (PPW) are estimated to hold 3-25milliont of oil. Other hazardous cargo in PPW includes ordnance, chemicals and radioactive waste. Here, we present and discuss studies on mercury (Hg) and oil pollution in coastal marine sediment caused by two of the >2100 documented PPW in Norwegian marine waters. The German World War II (WWII) submarine (U-864) lies at about 150m below the sea surface, near the Norwegian North Sea island of Fedje. The submarine is estimated to have been carrying 67t of elemental Hg, some of which has leaked on to surrounding sediment. The total Hg concentration in bottom surface sediment within a 200m radius of the wreckage decreases from 100g/kgd.w. at the wreckage hotspot to about 1mg/kgd.w. at 100m from the hotspot. The second wreck is a German WWII cargo ship (Nordvard), that lies at a depth of ca. 30m near the Norwegian harbor of Moss. Oil leakage from Nordvard has contaminated the bottom coastal sediment with polycyclic aromatic hydrocarbons (PAH). The findings from this study provide useful insight to coastal administration authorities involved in assessing and remediating wreck-borne pollution from any of the tens of thousands of sunken shipwrecks.