This report is a compilation of the investigation carried out in the Oxelösund area. The work presented in this report has dealt with the iron and steel indsutry, and the aim was to provide the cientific basis of an assessment of the total envrionmental impact of the current discharges of wastes, into ambient air and water, from a large integrated iron-and steelworks. The main object of these studies was the SSB steelworks in Oxelösund, which is the largest point sourece in the area. Using the criteria 'duration' and 'extention in space', a rough raking of the various biological effects observed has been made. Adverse effects with great extention in time and space must be considered much more harmful to the ecossystem than local, short-term effects. An attempt has also been made to establish to what extent the effects can be attributed to current discharges, and which of teh individual pollutants are responsible for a particular effects. Based on the total emission in 1981 from the iron- and steelworks, and the distribution of pollutants in the environment, a priority list has been drawn up over those components which are supposed to exercise the highest hazard to the environment. The assessment of the hazards of the atmospheric emissions provide the conclusion that sulphur dioxide, PAH and vandium shold be given the highest priority. Among the current discharges to coastal waers, oil (including additives,), ammonia and possibly PAH are given the highest priority.