NERI Technical Report No. 547: Contaminants in the Atmosphere. AMAP-Nuuk, Westgreenland 2002-2004. Skov, H., Bossi, R., Wåhlin, P., Vikelsøe, J., Christensen, J., Egeløv, A.H., Heidam, N.Z., Jensen, B., Ahleson, H.P. Stausgård, L., Jensen, I. & Petersen, D. 2005. 45 pp.
Summary
The Greenlandic population is exposed to heavy metals and persistent organic compounds (POPs) due to the amount of their diet originating from sea animals. Longrange atmospheric transport of air pollution to western Greenland, possibly from Canada or USA and in episodes also from Eurasia, is suspected to be one of the main causes.
Aim
The Aim of the measurements and results of model calculations presented in this report was to determine the load of selected inorganic and organic pollutant to West Greenland from in particular North America.
Monitoring sites
At Lille Malene Mountain close to Nuuk, the capital of Greenland, continuous monitoring of heavy metals including mercury, as well as ozone, NOx and sulphate were carried out. Furthermore, a series of POP’s were collected at the roof of ASIAQ building in Nuuk. The results are presented and discussed in this report. Use of a receptor model (COPREM) and an Eulerian model (DEHM) strengthened the interpretation of the monitoring data.
Heavy metals
The levels of particle bound heavy metals (excluding atmospheric mercury) and sulphur were very low. Analysis of data by COPREM showed that sea spray and crustal dust were the dominant source of inorganic particulate matter and that anthropogenic sources contributed with less than 8% of the inorganic particle mass.
Measured and modelled levels of Pb and SOx
The measured levels of SOx and Pb in Nuuk were reproduced by DEHM. However, the very low measured values of SOx and Pb concentrations made it impossible to use them to improve and develop the performance of DEHM.
O3 and GEM
A strong depletion of GEM was observed in May 2003 with values down to 0.6 ng m-3 without any correlation to ozone concentrations as observed at higher latitudes. In 2004 the situation was different, some relative sharp depletion episodes were observed in April with concentrations down to 0.6 ng m-3. Again there was not observed any correlation between GEM and O3 . The GEM depletion was in both years attributed to longrange transport.
New methods
For the first time a diffusive sampler for measuring atmospheric mercury was tested and used in the field. A pyrolyser was tested on a TEKRAN 2537A mercury analyser, which made it possible to measure directly total atmospheric mercury in the atmosphere.
NOx
NOx measurements clearly showed that the Lille Malene Station was affected by local anthropogenic pollution.
Chlorinated pesticides
A series of chlorinated pesticides was measured and found, generally at low concentrations. Hexachlorobenzene (HCB) was the compound found at the highest concentration. However, low collection efficiency was observed for HCB due to its high volatility. Lindane (? -HCH) atmospheric concentrations were found to increase in the summer period (from April to September). This indicates a contribution of longrange transport from the North American continent, where this pesticide is still in use.
PCDD/F
PCDD/Fs show a pronounced seasonal variation, characterised by high concentrations in the summer with maximum in July. Otherwise, the concentrations were close to the detection limit. This annual profile was attributed to local sources and most probably from garbage burning, whereas the local municipal waste incinerator could be excluded as a possible source.
c-PCBs and PCDFs in biota
The low concentration of c-PCBs in the atmosphere is in contrast with observations in Greenlandic marine biota (Vorkamp et al., 2004). This indicates that other sources than atmospheric longrange transport is the primary c-PCBs source to the Nuuk area. Contrary to this, PCDFs dominate in the atmosphere but are insignificant in biota. These examples also highlight the need to understand the transport of these species between the various matrixes.
Nitrophenols
The concentrations measured in snow indicate that deposition of nitrophenols will have negligible effects on the Greenlandic vegetation.
Conclusion
The overall conclusion is that the atmosphere in Nuuk is generally very clean apart from a small local pollution and a small contribution from longrange transport from anthropogenic sources located in North America.
Recommendation
The general low levels of pollutants (except PCDD/Fs) in Nuuk and the little importance of sources in North America make it obvious that the monitoring activities in the Greenlandic atmosphere have to focus on the transport from Eurasia to Greenland. Therefore, it is recommended to move the station to Station Nord in Northeast Greenland but at the same time to revise the monitoring programme so it will include the transport of new contaminants to the Arctic and so that it is coordinated with other national monitoring programmes under AMAP.
Full report in pdf-format (1,500 kB).
