Polluted river systems: Monitoring and assessment of ecotoxicological risks

In the past chemical, ecological, and toxicological research was carried ou t in a separate way. Nowadays, more and more studies are undertaken conside ring these three approaches in an integrated way (triad studies). A sophist icated combination of chemical and biological monitoring and bio-assays can improve water quality management of polluted rivers. Application of quanti tative structure-activity relationships (QSARs), algorithms for mixture tox icity of known substances, chemical group parameters, and response-oriented sum parameters, may reduce uncertainties in ecotoxicological risk manageme nt.