Sources of Environmental Contaminants into Lake Mjøsa

Overall, the results suggest a fairly complex source contribution of PCBs to lake Mjøsa, and that significant fluxes of PCBs are yet to be identified.

The results of this project furthermore suggest that the atmosphere is a key source of PCBs to lake Mjøsa, in comparison to preliminary estimates of the amounts discharged by rivers as well as sewage treatment plants. Elevated atmospheric levels of PCBs and PBDEs are in part attributed to long-range atmospheric transport of these compounds from other countries, whilst elevated levels of PBDE at Lillehammer suggest a local source to the atmosphere. The results finally indicate that the atmospheric deposition of mercury may primarily be explained by atmospheric long-range transport.