ABSTRACT

The knowledge about amounts and risks of heavy metals which are introduced into soils and plants by utilization of sewage sludge has increased rapidly. This was supported by the defined and limited number of heavy metals and the progress of analysis technics. By this a strategy for scientifically based handling of sewage sludge utilisation accompanied by a legal frame is possible. On the contrary the base for decisions concerning organic pollutants is still very small, even if some success about the contents of these substances in sewage sludge can be reported. Their occurence in soils and their influence on plants including transfer mechanisms are scarce. In consequence conclusions about risks of these substances are difficult. This situation was even worse at the time when the investigations started more than four years ago.