UMB 4: Conceptual Approaches to Predict Combined Toxicity
K.E. Tollefsen (NIVA/NMBU-IMV), L. Xie (NIVA), A.C. Almeida (NIVA), T. Gomes (NIVA), H.C. Teien (IMV-NMBU), K.A. Solhaug (INA-NMBU), B. Johnsen (NRPA).
Background: Organisms are exposed to a combination of stressors (multiple stressors) from different sources and the combined effects of these are often unknown. Although combined toxicity assessment (CTA) of mixtures of chemicals is well established, development and evaluation of well-defined and scientific credible predictive approaches to accommodate effects of multiple stressors is urgently required.
Objectives: Develop and use prediction models to assess combined toxicity of multiple stressors.
Methods: Potential candidate stressors were identified on basis of their mode of action (MOA), species-specific adverse outcomes and ecological relevance. A suite of bioassays consisting of algae (Chlamydomonas reinhardtii), aquatic plants (Lemna minor) and crustaceans (Daphnia magna) has been optimised for CTA. Dedicated single and multiple stressor studies will be used to assess combined toxicity by a suite of CTA prediction models.
Results: Of more than 100 potential stressors assessed, less than 20 representing UV radiation (UVR), ionising (gamma) radiation, metals and organic chemicals were selected as primary candidates for multiple stressors testing. Ongoing work focus on assessing multiple stressor effects on L. minor and C. reinhardtii.
Project Manager: Knut Erik Tollefsen
(Photos: H.B. Borchgrevink and X. Lie, NIVA)