Glahder, C.M., Asmund, G. & Riget, F. 2008: Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2007. National Environmental Research Institute, University of Aarhus, Denmark. 32 pp. – NERI Technical Report No. 662.
Summary
This forth monitoring study was carried out in the Nalunaq gold mining area, Nanortalik, South Greenland, on 18-25 July 2007. Seven shipments of ore had been transported to Spain and Canada for gold extraction since the last monitoring study performed August 2006.
Blue mussels, brown seaweed and shorthorn sculpin were sampled at 4-5 marine stations in the Kirkespir Bay, resident Arctic char were caught in the river and lichens Cetraria nivalis were collected at 20 stations in the valley and along the bay. In addition, lichens were transplanted from an uncontaminated area (AMI1) to the mining area (Fig. 1). Collected samples were analysed for 12 elements (Hg, Cd, Pb, Zn, Cu, Cr, Ni, As, Se, Co, Mo and Au) and the results were compared both to background levels and former monitoring studies.
No elevated concentrations were found in mussels and sculpin livers, while seaweed had slightly elevated Co concentrations at one sampling station. Thus, metal elevations were very few in the bay indicating a very low impact on the marine environment in 2007. Compared to higher concentrations in mainly seaweed in 2004 and 2005 the concentrations of metals in the marine environment appear in the last two years to have stabilised around the baseline level.
In resident Arctic char livers no concentrations were elevated. Compared to the three previous years, Cr, Co and Cd were slightly elevated in 2004 and 2006, while no elevations were found in 2005.
In lichens, concentrations of Cu, Cr, As and Co were, like in the previous years, significantly elevated compared to the background level in the depot and the camp area. Elevations in the two areas in 2007 were 5 times for Cu and Cr, 15-20 times for As and 10 times for Co. Concentrations of the four metals in the two areas were significantly higher in 2007 than in 2006, but no trend during 2004-07 is indicated. During 2004-2007, concentrations in lichens of Cu and As were significantly higher in the camp than in the depot area. The relationship between metal concentrations in lichens and the distance to the gravel road did not differ significantly between the years 2005-2007 for any of the metals. All metal concentrations showed a significant decrease with increasing distance (Fig. 3). Concentrations of Cu, Cr, As and Co above the background level could, as in previous years, be found to a distance of about 1000 m from the road.
Because metals are excreted from lichens at a low rate it can be difficult to detect a reduction in dust pollution. In 2007 we therefore transplanted lichens from an unpolluted area to the Nalunaq area. By analyzing them in 2008 the rate of dust pollution can be determined.
As in previous years, an impact from the mining activities on the local environment could be seen in 2007, primarily in the Kirkespir Valley from dust dispersal. In the river and in the bay, element elevations were very few and the impacted area was as small as in 2006.
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