Environmental monitoring at the lead-zinc mine in Maarmorilik, Northwest Greenland, 2007. Johansen, P., Asmund, G., Rigét, F. & Johansen, K. 2008: National Environmental Research Institute, University of Aarhus. 54 pp. – NERI Technical Report No. 684.

 

Summary

At Maarmorilik in the municipality of Uummannaq lead and zinc ore was mined from 1973 to 1990 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 fjord Affarlikassaa to a processing plant in Maarmorilik. Here a lead and a zinc concentrate were produced and loaded on ships, which transported the concentrates to smelters in Europe.

 

There were a number of sources of pollution while mining took place. Ore crushing and transport of concentrate created dust that was dispersed in the environment. Waste rock dumps with low contents of lead and zinc were also a dust source, but lead and zinc were also released from them to freshwater and the sea. The most important pollutant source, however, was the mine tailings that were discharged into and settled in Affarlikassaa. After mine closure a waste rock dump was excavated and dumped in Affarlikassaa on top of the tailings.

 

Environmental studies have been conducted at the mine since 1972 by monitoring lead and zinc in seawater, sediments and biota in the fjords at Maarmorilik. Studies of the benthic fauna have also been carried out. This report presents the results of environmental studies conducted in 2007 and assesses the state of the environment in the area. The results are compared with data collected from 1972 to 2005.

 

The lead and zinc dispersal with dust around Maarmorilik has been monitored by the use of the lichen Cetraria nivalis. This species can be used to monitor dispersal of metals in the atmosphere, as it only takes up water, nutrients and contaminants from its surface. In 2007 elevated lead levels in lichens were found in the areas around Affarlikassaa and Qaamarujuk and on the northern coast of Perlerfiup kangerlua, whereas the area affected by zinc was smaller.

 

The pollution of seawater has changed drastically since mine closure, after which only small amounts of lead have been released from settled tailings and waste rock in the fiord Affarlikassaa. Zinc is still released, but clearly less than when mining took place. In the bottom water of the fiord, the lead concentration was about 1,000 times lower and the zinc concentration about 6 times lower in 2007 than in 1988-89. Lead concentrations in surface waters of Affarlikassaa have remained very low after mine closure and were not elevated in 2007. This is not the case for zinc. In 2005 and 2007 zinc concentrations in surface waters of Affarlikassaa were at the same level as in 1988-89 after having been about 3 times lower in the period from 1995 to 2002.

 

Brown algae in the tidal zone take up metals from the surrounding water and can be used to monitor seawater pollution. Over the monitoring period, where comparable data exists (1981-2007), both the lead and zinc concentrations have decreased significantly, especially after mine closure and lead levels have decreased more than zinc levels. In 2007 lead concentrations were elevated in all of the study area: Affarlikassaa, Qaamarujuk and Perlerfiup kangerlua. Zinc concentrations were elevated in a smaller area: in Affarlikassaa and Qaamarujuk but outside these fjords only on the northern coast of Perlerfiup kangerlua.

 

Also blue mussels from the tidal zone take up metals from seawater, algae and particles, and are suited to monitor metal pollution. In blue mussels sampled in 2007 lead levels above background are found in Affarlikassaa, Qaamarujuk and Perlerfiup Kangerlua. Elevated zinc concentrations are found in a small area close to Maarmorilik. In previous years the lead concentration in blue mussels was so high, that local people were advised not to collect and eat blue mussels from these fjords. But as the studies in 2005 and 2007 showed that the lead contamination of the blue mussels in the fjords had declined significantly, we now recommend diminishing the area with restrictions to Affarlikassaa, Qaamarujuk and the area just west of here. The lead and zinc concentrations in blue mussels have been declining over a number of years, but lead levels only slowly, because the mussels cannot eliminate all the lead taken up originally.

 

As one of the most stationary fish species, shorthorn sculpin is used to monitor the metal contamination of fish. In 2007 we found elevated lead concentrations in the livers of sculpins caught at Maarmorilik, but levels have decreased significantly in recent years. In muscle tissue levels are not elevated.

 

In northern shrimp caught in Qaamarujuk the lead concentration is elevated in 2007. Since 1988, lead concentrations in shrimp have been clearly declining, but most in the beginning of this period.

 

The elevated lead concentrations found in the fjords at Maarmorilik have been a cause of concern for public health, when people consume fish and other biota, but except for blue mussels as mentioned above, lead concentrations found in 2007 are below guidelines set to protect human health.

 

The environmental studies conducted in 2007 show that pollution sources still exist at Maarmorilik 17 years after mine closure in 1990. We can still see elevated lead and zinc levels in the environment. However, over a number of years lead and zinc levels in seawater and biota have decreased, in particular after the mine closed, and the area affected by pollution with lead and zinc has become smaller and smaller over the years. It is now primarily in Affarlikassaa and Qaamarujuk, an impact can be seen.

 

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