Aarhus Universitets segl

No. 775: Environmental monitoring at the former lead-zinc mine in Maarmorilik, Northwest Greenland, in 2009.

Johansen, P., Asmund, G., Rigét, F., Johansen, K. & Schledermann, H. 2010. Environmental monitoring at the former lead-zinc mine in Maarmorilik, Northwest Greenland, in 2009. National Environmental Research Institute, Aarhus University. 32 pp. – NERI Technical Report No. 775.

Summary

From 1973 to 1990 lead and zinc ore was mined at Maarmorilik in the region of Uummannaq by the mining company Greenex A/S. The ore was primarily found in the mountain called “Black Angel”. It was mined at an altitude of about 600 metres above sea level and transported in cable cars across the Affarlikassaa fjord to a processing plant in Maarmorilik. The produced lead and a zinc concentrate was loaded on ships and transported in bulk to smelters in Europe.

During mining different sources of pollution were identified. Ore crushing and transport of concentrate created dust that was dispersed into the environment. Waste rock dumps were another source for dust but also for the release of lead and zinc to the aquatic environment (e.g. the surrounding fjords). The most important pollutant source, however, was the mine tailings that were discharged into the Affarlikassaa fjord and settled there. In addition, after mine closure, a waste rock dump was excavated and dumped into the Affarlikassaa Fjord on top of the tailings.

Since 1972, environmental studies have been conducted in the vicinity of the mine and the fjords around Maarmorilik by monitoring lead and zinc contents in seawater, sediments and biota (seaweed, mussels, fish, prawns and lichens). This report presents and assesses the results of the environmental studies conducted in 2009.

The lead and zinc dispersal with dust around Maarmorilik were monitored using the lichen Cetraria nivalis. It is a good indicator for dispersal of metals in the atmosphere, since it takes up water, nutrients and contaminants via its surface. Lichens, transplanted in 2008 from a reference site to locations near Maarmorilik, showed increased levels of lead and zinc in 2009. Clearly elevated lead concentrations were found in lichens from sampling sites in Affarlikassaa, Qaamarujuk and at Qeqertanguit about 12 km west of Maarmorilik with levels between about 2 to 10 ?g/g dry weight above background. Zinc concentrations were not elevated to as high levels as lead and were elevated only within a short distance from Maarmorilik. There is no indication that the dispersal of lead and zinc with dust has changed since 1996, when we introduced the lichen transplantation study to evaluate temporal changes of the dust pollution.

Blue mussels were used to monitor metal pollution in the marine environment since they take up and accumulate metals from seawater, sediment and food particles. In 2008, blue mussels from an unaffected site were transplanted to 8 sites at different distances from Maarmorilik. These were sampled one year later in 2009. The lead content in transplanted mussels was elevated in Affarlikassaa, Qaamarujuk and at Qeqertanguit. Zinc concentrations were elevated in a much smaller area and only close to Maarmorilik. After mine closure the lead contamination in transplanted mussels has decreased significantly, on average by 5.5% per year, with decreases ranging from 2.2% to 8.6% dependent on locality.

As an overall conclusion it is observed, that after mine closure in 1990 an impact from the previous mining operation can still be seen in 2009. The pollution with dust on land seems to continue with no signs of a decrease, while the pollution in the sea is decreasing.

Full report in pdf (2.32 MB)