During the months June-July 2000, a study was performed in 'De Westhoek' by means of a mobile laboratory. The mobile unit was set up at the municipal technical service (Zwartenhoekstraat - Adinkerke). Simultaneously measurements were carried out at Adinkerke and Houtem (Veurne) to determine heavy metals in suspended particulate matter. The report also includes the results of the dioxin-deposition monitoring carried out in October-November 1999, April-May 2000 and November-December 2000. Moreover, ammonia was measured by Vito at Knokke, De Panne, Houtem and Diksmuide in the period of December 1999- October 2000. These studies are all part of the Interreg II-project. This project started in 1990 with the aim to assist the border region with specific problems resulting from their distant location. The concerns of the local population and the respect of the environment were the center of interest. Within the Interreg II framework, a research project was approved to determine the cross-border air pollution between the north of France (Nord-pas-the-Calais) and Flanders (Westhoek).The presence of an industrial infrastructure within the vicinity of an urban population was the basis for setting up this project. As function of the wind-direction a cross-border pollution can occur in any of both directions. The results of the mobile unit were far below the limit-values for SO 2 . NO 2 , CO and PM 10. Moreover, the results for heavy metals were very low. Even lower than background-measurements at Knokke. Except for ozon, no increased concentrations of the determined pollutants were found during this campaign. It has to be stipulated that the measuring period was only 45 days and the wind direction came from the sector 235°-295° (direction Duinkerke) for about 17% of the time (7,5 days). Two new campaigns were organised in December-January 2000 and May-June 2001. The results will be discussed in the final report. All dioxin-depositions in Adinkerke, De Panne, Veurne and Poperinge remained beneath the limit-values. Only in ...