Poul Johansen

Lead, cadmium, mercury and selenium in Greenland marine animals

Baseline concentrations of lead, cadmium, mercury and selenium are reported from different tissues in marine organisms from Greenland. Overall, lead levels in marine organisms from Greenland are low, whereas cadmium, mercury and selenium levels are high. Tissue differences are not very distinct for lead, whereas the opposite is the case for cadmium and mercury. Selenium shows an intermediate behaviour in this respect. In general, lead concentrations do not correlate with the age/size of animals, whereas cadmium, mercury and selenium increase with age/size of most species and tissues analysed. No clear conclusions can be drawn in relation to geographical differences in lead, mercury and selenium concentration in Greenland. In general, cadmium levels are higher in Northwest Greenland compared to southern areas. Local differences with increasing cadmium levels from inner fjords to the open sea in stationary species may be of the same order of magnitude as those observed over long distances in Greenland. There is no indication that lead and selenium levels increase in higher trophic levels, although this is clearly the case for cadmium and mercury. In almost all cases lead levels in marine organisms from Greenland are well below the Danish food standard limits, however, a substantial proportion of marine mammals and seabirds in Greenland have cadmium and mercury levels exceeding the Danish standard limits. No food standard limits are given for selenium in food, but in some cases human intake of selenium is estimated to be high.

Comparison of contaminants from different trophic levels and ecosystems

The present paper provides an overview of the priority contaminants and media from the Greenland part of the Arctic Monitoring and Assessment Program. Levels and accumulation patterns of heavy metals, POPs and a radionuclide (137Cs) are compared from the terrestrial, freshwater and marine ecosystems. Of the nine compounds presented, seven (Cd, Hg, Se, sigma PCB, sigma DDT, sigma HCH, HCB) increased in concentration towards higher trophic levels. For these contaminants the concentrations in soil and aquatic sediment were in the same order of magnitude, whereas the concentrations in marine biota were higher than found in the freshwater and terrestrial ecosystems probably due to the presence of longer food chains. Pb and 137Cs showed the reverse pattern compared with the other compounds. The concentrations in soil and aquatic sediments decreased in the order terrestrial, freshwater and marine ecosystems, which was reflected in the biota as well. Reindeer had similar or lower levels of Pb and 137Cs than lichens. Levels of Pb and 137Cs in marine biota did not show the same clear increase towards higher trophic as found for the other analysed compounds. Greenland Inuit contains considerably less mercury but higher levels of sigma PCB, sigma DDT and HCB than other Arctic marine top consumers.

Lead, cadmium, mercury and selenium intake by Greenlanders from local marine food.

The human intake of lead, cadmium, mercury and selenium from local Greenlandic marine food was estimated based on dietary studies and contaminant information. The average lead intake was calculated to be 15 micrograms/person per week, which is very low, whereas the intake of cadmium and mercury was estimated to be very high, on average 1004 micrograms/person per week for cadmium and 846 for mercury, thereby significantly exceeding limits established by FAO/WHO. The main cadmium and mercury source was seal liver. Selenium intake was also high with whale skin as the dominant source.

Uptake and release of lead and zinc by blue mussels. Experience from transplantation experiments in Greenland

Studies of release and uptake of lead and zinc in blue mussels have been used to assess the environmental impact of a lead-zinc mine in Greenland. Blue mussels were transplanted from a clean area to highly polluted sites near the mine, and also from a highly polluted site to a clean area. The uptake and release of lead were found to be slow processes. After two to three years of accumulation the level in the transplanted mussels reached the level of the resident population. After two to three years in a clean environment the release of lead ceased, and the mussels seem be able to depurate only about half of the lead originally taken up. The pattern of uptake and release of zinc was not as clear as for lead indicating a certain regulation capability of the mussels. When pollution with lead in the environment decreases, resident mussel populations were found not to be useful as monitoring organisms. Transplantation of mussels seems to be a good monitoring tool in that situation.

Baseline levels and natural variability of elements in three seaweed species from West Greenland

Element levels in three seaweed species (Fucus vesiculosus, F. distichus and Ascophyllum nodosum) from different sampling sites in a West Greenland fjord system were determined during a three year period. The elements studied were Cd, Cu, Pb, Zn, Na, Ca, Sc, Cr, Fe, Co, As, Br, Rb, Sr, Cs and Ce. The variability of element concentrations showed a complicated pattern. Differences between both species and localities were found for most elements. Species differences were found to depend on the locality. In most cases where differences between seaweed species were found, concentrations were lower in A. nodosum than in F. vesiculosus which in turn were lower than in F. distichus. At the outer part of the fjord system concentrations of Na, Br and Cd were considerably higher than in the inner part while concentrations of Ca, Fe, Co, Ce, Sr, Sc and Cu were lower. Pb and Zn concentrations show no consistent geographical pattern. The results from a principal component analysis were difficult to interpret. The possible underlying factors controlling the variability of element concentrations are poorly understood. The influence of seawater on the fjord system and variations in run-off from rivers may account for a significant part of the variability seen for many elements. The concentrations of most of the elements, especially the heavy metals, were relatively low compared to other areas in Europe and North America.

Marine Organisms as Indicators of Heavy Metal Pollution-Experience from 16 Years of Monitoring at a Lead Zinc Mine in Greenland

Abstract In monitoring the impact of a lead-zinc mine in Greenland, species of fish, prawns, seaweed and mussels have been analysed for cadmium, copper, lead and zinc for several years. These metals have been released to the marine environment in significant amounts from the mining operation.

Lead, cadmium, mercury and selenium in Greenland marine biota and sediments during AMAP phase 1

Lead, cadmium, mercury and selenium levels in the Greenland marine environment from the first phase of the AMAP are presented. Samples were collected in 1994-1995 covering four widely separated regions in Greenland. Samples included sediments, soft tissue of blue mussel; and liver of polar cod, shorthorn sculpin, glaucous gull, Iceland gull and ringed seal. Concentrations of lead were found to increase with the size of blue mussel, but not with the age of gulls or ringed seal. Both cadmium and mercury concentrations were found to increase with the size/age of all species. Selenium concentrations decreased with increasing size of blue mussel, but increased with the age of gulls and ringed seal. Element levels found are within the range of those found in previous studies in Greenland. Relative to global background levels, lead levels must be considered low, whereas levels of cadmium, mercury and selenium in Greenland marine biota are high. Significant differences in element levels in sediments and biota among regions in Greenland were seen in several cases. There was a tendency for the highest lead and mercury concentrations to be found in east Greenland, whereas the highest cadmium concentrations were found in central west Greenland. However, the geographical differences among the media did not show a consistent pattern.

Pollution from Mining in Greenland: Monitoring and Mitigation of Environmental Impacts

In Greenland, mining started as early as the 1850s and has taken place for copper, graphite, coal, cryolite, lead, zinc, and silver, but at present no mines are in operation. Environmental protection in connection with these operations was not an issue dealt with until the early 1970s, when the largest mine in Greenland was to start operating. Since then a legal framework has been developed for environmental protection in connection with exploration and exploitation of minerals in Greenland with standards similar to those used in North America and Western Europe. Monitoring and assessment of environmental impacts have been part of this process, in which the authors of this chapter have been deeply involved.