Abstract :
Athough the Netherlands is only a small country, it has the world\´s largest port in terms of annual tonnage. This is Rotterdam, situated in the area where the rivers Rijn and Maas loin, prior to reaching the North Sea. Their estuary forms a complex waterway; the main one being the "New Waterway," shown on the map Figure 1. South of this is a complex of harbours and industrial areas embracing six oil retineries, chemical plants, shipyards, metal works, etc. The residential areas within this complex suffer tfrom the air pollution associated with heavy industry.
