3. Conclusions

The traditional approach in monitoring is based on the choice of a list of compound of concern (from ecotoxicological data, information on use and expert judgment), their analytical determination, the study of their fate, distribution and biological effects by laboratory tests and finally evaluation of the risk assessment for the consumer or ecosystem. This approach is limited to a selected list of known chemicals for which we have at least preliminary information on use, occurrence and biological effects. It is not possible to be confident that the compound which affects the ecosystem or health is actually included in this list. The awareness that there are hundreds (if not thousands) of chemicals in discharges and natural waters and many of them can elicit sub-chronic effects, even if they are present at concentrations of nanogram or sub-nanogram per litre, gave a pulse to the development...