Modeling the fate of polychlorinated biphenyls in the inner Oslofjord, Norway

Abstract

A dynamic, segmented, multimedia fate and transport model has been developed, evaluated, and applied to gain insight regarding the behavior of seven polychlorinated biphenyl (PCB) congeners in the Inner Oslofjord (Norway). A comparison with a dated sediment core reveals that the model is not capable of reproducing some key features of the observed, historical, long-term trend in sediments, although better agreement is observed for six of seven PCB congeners over the last two decades. The model also underestimates the concentrations of PCBs in surface sediments in areas adjacent to the city of Oslo (Norway). In general, deviations between modeled and observed concentrations indicate that the historical emissions and discharges of PCBs are not sufficiently characterized and described. Net fluxes predicted by the model suggest that several congeners may have experienced a reversal of air-water and seawater-sediment exchange during the last decade or even earlier. The present study further suggests that the benefit of the proposed removal of the most contaminated sediments of the Inner Oslofjord needs to be assessed, with consideration of the relative contribution of current atmospheric inputs as well as the leaching of PCBs from less contaminated sediments.

Understanding of Cyclic Volatile Methyl Siloxane Fate in a High Latitude Lake Is Constrained by Uncertainty in Organic Carbon–Water Partitioning

“…The models consist of one water and one sediment compartment assuming these are homogeneous and well mixed. Previous dynamic developments of the QWASI model , have allowed annual changes in emissions, and seasonal changes in environmental conditions, but not episodic emission events. Here, daily fluctuations in emissions, water temperature and river inflow were incorporated.…”

Influence of historical industrial epochs on pore water and partitioning profiles of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in Oslo Harbor, Norway, sediment cores

“…According to the city of Oslo's official website (http://www.vann-og-avlopsetaten.oslo.kommune.no/avlopshandtering/), 94 to 98% of wastewater is now treated before entering the fjord (with the remainder attributed to overflow events), with phosphate removal rates typically > 90% and nitrate typically > 70%. Anthropogenic particles and contaminants continue to be introduced via overflow events, urban runoff, deposition of riverine particles [27], and atmospheric deposition [28].…”

Differences in Trophic Level, Contaminant Load, and DNA Damage in an Urban and a Remote Herring Gull (Larus argentatus) Breeding Colony in Coastal Norway

“…This was expected, because higher concentrations of legacy POPs in general are associated with marine feeding and higher δ 15 N values as a result of distribution and accumulation of these contaminants in marine food webs and a more lipid‐rich diet in the marine‐feeding gulls leading to higher exposure (Bustnes et al, 2013 ). In the urban Oslofjord, higher concentrations in marine feeders can be explained by PCBs still being present in the inner Oslofjord due to leaching from legacy contamination (Breivik et al, 2004 ). However, the trend of higher concentrations of POPs with higher trophic position has not always been observed for PBDEs.…”