Assessment of persistent and bioaccumulating chemicals in the aquatic environment.

In recent years several national and international organizations have initiated actions to control the use and release of persistent, bioaccumulative and toxic substances (PBTs). Consequently, a number of criteria have been proposed for the classification of these parameters. The scientific bases for PBTs assessment has grown a great deal over the last decades. In some specific areas reliable predictive capability exists while in other areas considerable uncertainty is still present. This paper will briefly point out the achievements and limitations of the knowledge on persistence and bioaccumulation with reference to the aquatic environment.