| Front page | | Contents | | Previous | | Next |

AMAP Greenland and the Faroe Islands 1997-2001

7 Conclusions and recommendations

7.1 Conclusions

7.1.1 Atmospheric environment

• The High Arctic is burdened with a considerable atmospheric pollution, consisting of a wide variety of acidic and toxic compounds, which originate in mid-latitude industrial areas. It has been demonstrated by the combined use of long-term field measurements and sophisticated large-scale meteorological and chemical transport models.
  
• For the northern part of Greenland mainly Russian sources contribute, while for the western and the southern parts it is North American and European sources.
  
• The combination of long term field data measurements and model calculations has also been highly useful in assessing trends in atmospheric concentrations. The emissions of Pb, Zn, Ni, As, Cu and S from the source areas in the Northern Hemisphere, which contributes to the concentrations in the High Arctic, have decreased with 50 % between 1990 and 2000.
  
• The levels of Hg have increased considerably due to the human activities. Furthermore new results have shown, that the Arctic acts as global sink for Hg due to the depletion process for Hg during the Polar Sunrise. Measurements and atmospheric modelling have shown that the deposition of Hg in the northern part of Greenland increases with up to a factor of 3 due to this phenomenon dependent on the ratio between re-emission of Hg from the snow pack during melting period.

7.1.2 Terrestrial environment

• Cadmium concentrations in terrestrial biota are low compared to marine biota. The Cd levels in Greenland terrestrial birds and mammals are in the range found in other Arctic regions. No temporal trend could be detected in Cd levels from 1994 to 1999.
  
• Mercury and selenium concentrations in terrestrial biota are low compared to marine biota but relatively high compared to the levels found in other Arctic regions. There were indications of lower Hg and Se levels in terrestrial biota in 1999 than in 1994/95.
  
• Peat studies in the AMAP area show a general elevation of deposition of Pb and Hg since the beginning of industrial times – yet falling in the last 10-20 years in case of Pb and possibly also for Hg.
  
• Organochlorine levels in Greenland terrestrial biota were low and much lower than in the marine biota. Even in fat of musk ox and lamb were OC levels low. The dominant OC was PCB.
  
• Caribou and lamb hold the highest ¹³⁷Cs concentrations in the terrestrial environment, and long ecological half-lives are seen because of the environmental conditions.

7.1.3 Fresh water environment

• Mercury concentrations in landlocked Arctic char in Greenland are relatively high especially in southwest Greenland. No significant difference was found in Hg concentrations in Arctic char from southwest Greenland between 1994/95 and 1999.
  
• Organochlorine levels in landlocked Arctic char were in the same range as found in marine fish species. No consistent geographical pattern of OC concentrations was observed. Concentrations of ΣDDT, ΣHCH and ΣCHL were lower in a southwest Greenland Arctic char population in 1999 than in 1994. No significant changes were found of ΣPCB-10 and HCB concentrations between 1999 and 1994.
  
• ¹³⁷Cs / ⁹⁰Sr activity ratios in fresh waters have decreased from the fallout level around 1.5 to the present levels varying between 0.03 and 0.46. This indicates a large variability in drainage area and lake characteristics.
  
• Due to special environmental conditions, ¹³⁷Cs from global fallout is still transferred to landlocked Arctic char with extremely high efficiency in south Greenland.

7.1.4 Marine environment

• Greenland marine sediments are not enriched by arsenic as reported for large areas of the Barents Sea.
  
• Recently observed Cd, Hg and Se levels in marine biota were generally within the range observed previously. The recent Cd data confirms the previously observed relative high level in the marine biota from Qeqertarsuaq (central west Greenland) compared to other Arctic regions. Beside that, no pronounced difference in Cd levels between marine biota from west and east Greenland was observed. Hg levels tended to be higher in east Greenland than in west Greenland for shorthorn sculpin, black guillemot (egg) and ringed seals, whereas polar bears appear to show the opposite trend.
  
• Only few time series of Cd and Hg data covering the recent 20 years are available so no firm conclusions can be made concerning trends. Cd in ringed seals from Avanersuaq and Ittoqqortoormiit tended to have lower levels in 1994 and 1999/2000 than in the mid 80’ies. In Qeqertarsuaq Cd levels tended to be higher in 1994 than in 1999/2000 in ringed seals, and Hg concentrations in blue mussels and ringed seals tended to have higher levels in 1994 than in 1999. In Avanersuaq, Hg levels in ringed seals showed an increasing trend from the mid 80’ies to mid 90’ies and again to 1999/2000. In Ittoqqortoormiit, no appearent trend in Hg levels was observed in ringed seals and polar bears.
  
• Seabirds hunted with lead shot have significantly elevated lead levels in their muscles. This probably constitudes the most important single lead source in Greenland human diet.
  
• A considerable amount of new OC data in marine biota has become available since AMAP phase 1. In marine fish the highest OC levels were found in bottom fish-eating species such as Greenland halibut. In seabirds, the highest OC levels were found in opportunistic feeders such as glaucous gull and in species wintering off North America and Europe such as kittiwake. The highest OC levels in marine mammals were found in narwhals, beluga and polar bear. Considerable evidence now exists of higher OC levels in marine biota from east Greenland than from west Greenland.
  
• In general, OC levels in biota from west Greenland were comparable with OC levels found in similar species from east Arctic Canada, whereas biota from east Greenland were intermediate the levels in west Greenland and Svalbard or at the same level as found in Svalbard. Circumpolar patterns of ΣPCB, ΣDDT, ΣCHL in ringed seal, minke whales and polar bears generally increase eastward from east Arctic Canada, west Greenland to east Greenland and Svalbard, whereas the opposite trend was found for ΣHCH.
  
• OC concentrations in biota from Qeqertarsuaq showed no consistent changes from 1994 to 1999/2000. In shorthorn sculpin from Ittoqqortoormiit ΣPCB and ΣHCH were significantly lower in 1999/2000 than in 1994. This was also the case ΣHCH in male ringed seals. In polar bears from Ittoqqortoormiit in 1999/2000, ΣPCB and ΣCHL levels were considerably lower than in 1990.
  
• Concentrations of ⁹⁹Tc, ¹³⁷Cs and ⁹⁰Sr in seawater are decreasing in the order North East Greenland and the coastal East Greenland Current > south west Greenland > central west Greenland and north west Greenland > Irminger Sea ~ Faroe Islands. This is caused by the general large-scale oceanic circulation combined with European coastal discharges and previous contamination of the Arctic Ocean. The same tendency is seen in marine biota. The peak ⁹⁹Tc discharge from Sellafield 1994-1995 has only been slightly visible in year 2000. The concentrations are expected to increase in the future, especially in east Greenland.
  
• In the plutonium contaminated Bylot Sound, biological activity has mixed plutonium efficiently into the 5-12 cm new sediment resulting in continued high surface sediment concentrations 3 decades after the accident in 1968. Transfer of plutonium to benthic biota is low – and lower than observed in the Irish Sea. This is supposed to be caused by the physico-chemical form of the accident plutonium. A recent study indicates that “hot particles” hold considerably more plutonium than previously anticipated and that the Bylot Sound sediments may account for the major part of the un-recovered amount, i.e. around 3 kg.

7.1.5 Other contaminants

• Tributyltin (TBT)
  TBT and degradation products were detected in the marine environment in mussels sampled outside Nuuk and in harbour sediments. The TBT levels in mussels were low compared to Danish coastal waters.
  
• Dioxins, furans and coplanar PCBs
  Dioxins, furans and coplanar PCBs were detected in polar bears. Compared to marine mammals in other Arctic regions the concentrations were relatively low.
  
• Toxaphene
  Toxaphene concentrations in the Greenland marine biota were within the range observed in other Arctic regions. Toxaphene levels in Greenland terrestrial biota were lower than in marine biota. The highest toxaphene levels were found in marine mammals especially narwhals.
  
• Chlorobenzene
  The highest chlorobenzene concentrations were found in blubber of narwhal and beluga. The by far dominating chlorobezene in Greenland biota is hexachlorobenzene (HCB).
  
• New chlorinated pesticides
  The highest levels of aldrin, dieldrin, endrin, heptaclor, endosulfan, methoxychlor and mirex were comparable to levels detected elsewhere in the Arctic. Data on levels of endosulfan and methoxychlor, two chlorinated pesticides still in use, in Arctic biota are sparse. The concentrations found were lower than observed in more industrialized parts of the world.
  
• Polybrominated diphenyl ethers (PBDE)
  PBDEs are found in all organisms analysed, as a result of not only long-range transport but also local sources. The concentrations measured are lower than found in industrialized parts of the world and below levels that can acutely affect organisms detrimentally.
  
• Polycyclic aromatic hydrocarbons (PAH)
  PAH levels in south Greenland are of the same magnitude as levels measured in more urbanized parts of the world, even exceeding the EAC values (OSPAR) for e.g. anthracene. The highest levels were found in fish, e.g. shorthorn sculpin indicating a higher potential for bioaccumulation than seen in the Temperate Zone.
  
• Contaminants of future concern
  The compound groups PFOS, synthetic musks, polychlorinated naphthalenes, other brominated flame retardants (HBCD, TBBPA and PBB), polybrominated dibenzodioxins and dibenzofurans, aromatic amines and the biocide triclosan are examples of high volume chemicals of high international concern found in the environment at lower latitudes. Studies have indicated the presence of some of these compounds in the Arctic.

7.1.6 Effects

• Although histopathological changes were observed in 10% of the ringed seal kidneys these were not specific enough to be concluded as cadmium induced. No demineralisation in the skeletal system could be linked to cadmium levels and/or nephropathological changes in selected ringed seals from northwest Greenland with high cadmium levels in the kidney. Furthermore the degree of mineralisaton of the skeleton was not correlated with gender but was highly significant correlated to age.
  
• Based on interviews of aboriginal polar bear hunters in East Greenland 13 macroscopic pathological changes in 1110 bears were reported. However, it is yet unknown whether these abnormalities are related to contaminant levels.
  
• So far a single pseudohermaphrodite (female) out of 94 (35 identified females) examined polar bears have been observed.
  
• Preliminary results shows that female polar bears are lower in bone mineral density than males, but it is so far uncertain to say whether post menopansa bears and recently sampled bears suffer from contaminant induced osteopenia.
  
• Frequencies of parodontitis increase significantly with age of polar bears but no temporal trends have so far been detected.
  

7.2 Recommendations

7.2.1 Atmospheric environment

• Maintain Station Nord as a High Arctic monitoring and research station as basis for field campaigns, and continuing measurements at Station Nord in order to maintain the long time series of measurements and to have a place for process studies.
  
• Perform long term monitoring in the high Arctic of atmospheric Hg and other relevant species and components.
  
• Identify the composition of reactive gaseous Hg as at present, it is unknown if the model results and measurements describe the same thing.
  
• Identify and describe the processes responsible for the removal of Hg from the atmosphere leading e.g. to accumulation in the snow pack.
  
• Develop tools (function/model) that would describe the above process and introduce these tools to the existing DEHM model, so that reliable model calculations can be made of the burden of atmospheric Hg to Arctic environment.
  
• Establish monitoring and model programs for POP’s based on the experience gained from the study of heavy metals including Hg.

7.2.2 Terrestrial Environment

• The monitoring of Cd and Hg levels in lichens, ptarmigan and caribou should continue at five year intervals in order to detect temporal trends.
  
• Studies of post depositional processes in peat should be continued supplementary to work in other environmental archives (sediments, snow/ice).
  
• Survey of ¹³⁷Cs levels in caribou and lamb should be continued from earlier sampling areas and preferably extended in south Greenland.
  
• A follow-up survey of plutonium levels in the terrestrial environment based on organic surface soil samples from areas where plutonium was detected after the Thule accident is suggested.

7.2.3 Fresh water environment

• The annual monitoring of Hg and OC levels in Arctic char from east Greenland, and the monitoring of Hg and OC levels in Arctic char from southwest Greenland at five year intervals should be continued in order to detect year to year variations and temporal trends.
  
• Radionuclide concentrations should be examined in landlocked Arctic char from a number of lakes in south Greenland – preferentially oligotrophic, low-ionic lakes from areas with a high precipitation rate. In addition to ¹³⁷Cs, the naturally occurring radionuclides ²¹⁰Po and ²²⁶Ra should be assessed in selected samples.

7.2.4 Marine environment

• The annual monitoring of Hg and Cd levels in sculpin, black guillemot and ringed seal from west Greenland and OC levels in sculpin, black guillemot and ringed seal from west Greenland should be continued in order to detect year to year variations.
  
• The monitoring of Hg, Cd and OC levels in sculpin, black guillemot and ringed seal from west and east Greenland at five year intervals should be continued in order to detect temporal trends.
  
• Supplement the existing time series of Hg levels in hair from polar bears back in time based on museum specimens is recommended.
  
• Few time series of OC levels in marine biota covering the last 25 years exist. Supplementing existing time series with samples from previously collected marine species would add considerably to the knowledge of recent temporal trends.
  
• Levels of especially ⁹⁹Tc and ¹³⁷Cs should be routinely monitored in seawater and biota especially from east and south Greenland and from the fishing banks.
  
• A survey of the naturally occurring radionuclide ²¹⁰Po in Greenlandic traditional diet, especially in seal, is recommended.
  
• A survey of the plutonium contamination in the Bylot Sound should be carried out in 2003 with special attention to be paid to the effect of hot particles and to possible changes in physico-chemical form that may increase bioavailability and mobility. The plutonium contamination in Bylot Sound should be monitored regularly, e.g. every 5 years.

7.2.5 Other contaminants

• Tributyltin (TBT)
  Screening of TBT baseline levels away from point sources in southwest Greenland is recommended, eventually in combination with effect studies. Furthermore, analyses of TBT in marine mammals are recommended because of the potential for bioaccumulation.
  
• Dioxins, furans and coplanar PCBs
  Further investigations regarding sources of these compounds and concentrations at lower trophic levels are recommended, taking the high potential for long-term detrimental effects into account.
  
• Toxaphene
  Time trend studies of toxaphene in key species are recommended in order to reveal if the ban of toxaphene at lower latitudes leads to a decrease in the marine Greenland environment.
  
• Chlorobenzene
  Time trend studies of HCB in key marine species are recommended.
  
• New chlorinated pesticides
  Time trend studies of these compounds in key marine species are recommended.
  
• Polybrominated diphenyl ethers (PBDE)
  An exponential increase in PBDE levels has been reported elsewhere, therefore it is recommended to incorporate this group of compounds in time trend studies for marine key species.
  
• Polycyclic aromatic hydrocarbons (PAH)
  The high PAH levels measured in fish call for further attention. Further studies including metabolism and effect studies are recommended. Furthermore additional baseline studies of PAHs are important, especially in connection with eventual oil exploration in Greenland.
  
• Contaminants of future concern
  A screening of the Greenland environment for the compounds PFOS, synthetic musks, polychlorinated naphthalenes, other brominated flame retardants (HBCD, TBBPA and PBB), polybrominated dibenzodioxins and dibenzofurans, aromatic amines and the biocide triclosan is recomended. If the screening reveals abundance for these compounds in the Greenland environment further studies regarding baseline levels and bioaccumulation are recommended.

7.2.6 Effects

• Clinical parameters (reproduction parameters a.o.) are difficult to study in Arctic wildlife like polar bears, as they range over vast and inaccessible areas, which may be very costly to approach. On the other hand laboratory studies on test set-ups and organisms like e.g. mink may not reflect the Arctic species and ongoing contaminant exposure. It is therefore important to conduct controlled studies on Arctic species, which have an intake of the actual high trophic marine Arctic diet.
  
• Cadmium kidney levels in seabirds from northwest Greenland and other Arctic areas are high enough to pose a threat for kidney damage. An effect study of renal changes in seabirds from the highest exposed areas and species in Greenland is therefore recommended.

| Front page | | Contents | | Previous | | Next | | Top |