From 1956 to 1963, lead ore was quarried by the company Nordisk Mineselskab at Mestersvig in east Greenland. The ore was crushed and purified by flotation. Tailings were discharged on a mountain slope and reached the bottom of the valley where it ended in a river that led the tailings further out to a delta by the fjord, where it was deposited with the natural sediments.

The concentrate was shipped in sacks. The sacks were loaded onto barges that were dragged over a shallow area to waiting ships in the fjord. Spills of lead concentrate when loading of the barges resulted in considerable lead contamination in some parts of the fjord. According to the reports, even entire loads were spilled when a barge keeled over.

We have been monitoring lead pollution since 1979. The latest monitoring report is from 2008. The studies have shown that there are two main sources of pollution: The river Tunnelelv and the port Nyhavn. Via a delta consisting of several forks, Tunnelelv runs out in the fjord, and the zinc contamination reaches a peak by these outlets. Lead contamination has also been detected here. However, the most comprehensive lead and zinc contamination is found at Nyhavn, where clear signs of spills from lead concentrate were observed as well. The studied specimens, which all have been more or less been contaminated near Mestersvig, include fresh and marine sediments, sculpins, scallops, discordant mussels and seaweed. 

Spreading of lead due to dust has been examined by analysing the lichens, Flavocetraria nivalis. Significantly increased concentrations of lead and zinc can be found up to 500 metres from the lead mine. Increased concentrations can be found five to ten kilometres from the mine. 

We plan to follow the development of the contamination in the future. The studies, which cover a period from 1979 until now, show that the contamination is decreasing, but also that it is expected to continue for many years to come.