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 (210Pb). 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.