How to Improve Toxicity Assessment? From Single-Species Tests to Mesocosms and Field Studies

Abstract The relationship between the concentration of a chemical substance in the medium and its effects on organisms must be quantified as well as possible because it is at the basis of the determination of the predicted no effect concentration that is a key parameter for environmental risk assessment. Thus, designing the procedures aiming at the determination of toxicological parameters must mobilize the most recent scientific knowledge. The present chapter provides a literature review allowing advances in biotesting practices, considering both the improvement of exposure scenarios (increasing the realism of the doses tested and of the ways of exposure), and the choice of more sensitive endpoints (growth, reproduction, behavior, and also subindividual effects linked to the success of reproduction). The quality of bioassays lies also on the relevant choice of biological models ( Chapter 10 ) and the use of the best available statistic treatments.