Measurements of atmospheric pollution have taken place at Station Nord in Northeast Greenland since 1990. Weekly samples have been collected for analysis of sulphur dioxide, sulphate in particles, total gaseous and particulate phases of reduced and of oxidised nitrogen. In addition concentrations of a considerable number of elements in aerosols have been determined by the PIXE method. The results show that although the levels of all pollutants are gener-ally very low there are large and recurrent seasonal variations where concentrations rise to considerable heights, similar to observations at other High Arctic sites. The periods of high concentrations fall in different seasons, primarily in winter, dependent on the type of pol-lution and the source type responsible. Winter concentrations of sul-phur have decreased in the last few years, possibly caused by re-duced emissions in the northern part of Russia. A receptor model is used for identifying the natural and anthropo-genic source types most important at Station Nord, for apportioning concentrations to these sources and for determination of the seasonal variation of the source strengths. The recurrent influence of remote sources on the air quality in the High Arctic indicates that large scale meteorological mechanisms, similar from year to year, are responsi-ble for the high concentrations. For the sulphur compounds this hypothethis is confirmed by model calculations. The results obtained with an Eulerian hemispheric model show that a significant atmospheric pollution transport from very distant sources in industrial areas in Europe and Russia takes place in winter. This transport often occurs in episodes The deposi-tion is however not very high. Measurements of ozone reveal a striking pattern in spring of sudden ozone depletion lasting from a few hours to a couple of days. The phenomenon is believed to be related to the Polar sunrise and the return of daylight that may initiate a photochemical activity involv-ing the ozone distrusting bromine, the origin of which remains un-clear.