Geochemical trends in metal-contaminated fiord sediments near a former lead-zinc mine in West Greenland

Disposal of sulfidic waste in marine environments implies an environmental risk due to potential release and spreading of heavy metals to sediments and biota on a regional scale. However, tailings disposal in marine systems is practised in several places. Fiord sediments near Black Angel Mine in West Greenland are contaminated by Pb and Zn as a result of mining activity and marine disposal in the period 1973-1990. Chemical analyses were performed on 6 fiord sediment cores collected up to 10 km away from the disposal area and included heavy metal analysis, high-resolution stable Pb isotope stratigraphy and radiochemical dating (Pb-210). The results were used for evaluating spatial and temporal distribution of anthropogenic heavy metals from the marine disposal. A significant accumulation of Pb and Zn on a regional scale is still observed 9 years after mine closure. Stable Pb-isotope data provide a unique fingerprint of the mining-related Pb sources in the area. Today spreading of mining-related Pb up to 10 km away from the mining area accounts for more than 80% of total Pb in sediment deposited within the last 100 years. (C) 2002 Elsevier Science Ltd. All rights reserved.