Ecotoxicology and Risk Assessment

Ecotoxicology is an integration of the ecological and toxicological effects of chemical pollutants on populations, communities and ecosystems combined with the fate (i.e., transport, transformation and breakdown) of pollutants in the environment. Fate + Effects = Hazard assessment

Risk assessment is a product of the intrinsic hazards of a substance combined with an estimate of the environmental exposure. Hazard + Exposure = Risk

The section for Ecotoxicology and Risk Assessment encompasses all aspects of environmental hazard and risk assessment, including computational predictions NCTP, Bayesian network modelling, fate assessments (i.e., persistence or biodegradability) effects assessments and biological monitoring. In an integrated approach, the section applies in silico techniques, in vitro assays (ranging from subcellular molecular tools to multiple cytotoxicity assays) and in vivo assays, covering the full spectrum of acute and chronic ecotoxicology test methods in both freshwater and marine organisms according to international test guidelines (e.g. OECD and ISO).

In addition to the diverse range of chemicals, different particle types and environmental stressors that we work with, the section is also involved with the centre of excellence for environmental radioactivity (CERAD).

Some of our areas of focus are:

  • System- (eco) toxicology
  • Regulatory ecotoxicology
  • Monitoring
  • "New"/emerging contaminants

Fate Assessment

The section routinely carries out fate assessments to determine the fate of chemicals in the environment. This is both within freshwater and marine environments and according to regulatory guidelines such as OECD 301, 306 etc. Our staff are fortunate to have access to deep water marine environments (60m) from our marine research station, which ensures a more constant microbial community than water taken at surface levels. The team are constantly developing new systems or making improvements to existing methods to ensure the fate of chemicals in the environment are properly assessed. In addition, we have developed lab scale batch reactor tests to simulate waste water treatment plants. A recent project within the section (NanoWaste) investigated the fate (and effects) of nanomaterials within waste water treatment plants. The determination of the possible persistence of a chemical is the first step in our hazard and risk assessment approach. To understand the fate of chemicals within biological organisms, we also perform fish bioaccumulation tests according to regulatory guidelines (e.g. OECD 305) or more bespoke studies looking at uptake of chemicals into bivalves such as mussels.


(Figure: NIVA)

Effects Assessment

The laboratory is approved for Good Laboratory Practice for the assessment of the following product groups:

  • pharmaceuticals,
  • veterinary medicine products
  • pesticides
  • biocides
  • food additives
  • industrial chemica

The approved areas of expertise include physical/chemical testing, bioaccumulation, biodegradation and ecotoxicity tests. Our dedicated research scientists are also able to design and perform bespoke complex ecotoxicity tests according to individual customer requirements. These range from small scale systems with algae and invertebrates to large scale fish studies. In addition, in cooperation with the NIVA algal culture collection, we have access to one of the largest collection of different species of algae in the whole of Europe. An example of our portfolio of ecotoxicity tests that we routinely perform are shown below:


  • Algae 72 hour growth inhibition (OECD 201)
  • 48 hour immobilisation test (OECD 202) Daphnia magna
  • 96 hour fish acute toxicity (OECD 203)
  • Fish Embryo Toxicity (FET) test (OECD 236) Zebrafish (Danio rerio)
  • Fish early life stage test (ELS) (OECD 210) Danio rerio
  • Fish juvenile growth test (OECD 215)
  • Sediment-Water Chironomid Toxicity test-spiked water or spiked sediment (OECD 218, 219)
    Lemna sp. Growth inhibition test (OECD 221)


213 collage eco
(Both photos: NIVA)




  • Algae 72 hour growth inhibition (ISO 10253) Skeletonema pseudocostatum
  • 48 hour immobilisation test (ISO 14669) Tisbe battagliai
  • 10 day Corophium sp. acute toxicity test (OSPAR)
  • 10 day Arenicola marina acute toxicity test (OSPAR)
  • 24 hour Oyster embryo larval study (ISO 17244)
  • 7 day larval development test Tisbe battagliai
  • 14 day reproduction test Tisbe battagliai
  • 96 hour fish acute toxicity (OECD 203)
  • Fish juvenile growth test (OECD 215)


collage eco3
(Collage: NIVA)



Biological effects assessment

Biological effects monitoring, using an integrative suite of biomarker responses, are important tools within the ecotoxicology section. They are used to provided environmental hazard assessments for a diverse range of industrial discharges including mining, aquaculture, sewage treatment and coastal and offshore oil and gas activities. Our staff are trained in many biological effects techniques that are measured in tissues, cellular fluids and whole organisms and show an exposure and/ or effect to one or more chemical contaminant(s). Model organisms include fish and mussel, which are used in laboratory controlled studies as well as field investigations using naturally occurring and field transplantation studies.

NIVA are the lead laboratory for the biomarker module within the BEQUALM inter-calibration programme. This ensures that the biomarker data are of highest quality and comparable to those produced by other European laboratories.

Integrated biomonitoring

Integrating chemical body burden data, together with biological responses from different levels of biological organisation, provides a holistic approach to environmental monitoring. The selected biomarkers measure both general health and fitness responses as well as specific genotoxic, neurotoxic and/or endocrine responses in exposed organisms.


Figure 2. Integrative biomonitoring scheme combining chemical concentrations and biological effects measurements in fish. Biological effects include general health status as well as specific genotoxic, neurotoxic, estrogenic and oxidative stress responses. (Note: a typical suite of biomarkers are included in the scheme although many other biomarkers can be used depending on the application).



Collage 213 (2)
Mussel caging and condition index (Photos: NIVA)




Mussels through microscope
Neutral lipid in digestive cells and micronuclei formation in mussels. (Photos: 1 and 2 from left: NIVA. 3: Figure 2 in Janina Barsiene (2008): "Environmental Genotoxicity Studies in Mussels and Fish from the Göteborg Area of the North Sea" in Acta Zoologica Lituanica 18(4):240-247.)



Systems toxicology

The systems toxicology (SysTox) team in the Section of Ecotoxicology and Risk Assessment mainly conducts research on the effects and underlying mechanisms of single and combined environmental stressors in a wide range of organisms, such as algae, aquatic plants, crustaceans and fish. By implementing the Adverse Outcome Pathway (AOP) concept and utilizing advanced analytical techniques such as high-throughput (HT) in vitro screening and high-content (HC) toxicogenomic tools (transcriptomics, proteomics, metabolomics and epigenomics), the SysTox team aims to mechanistically understand the effects of stressors occurring at different levels of biological organization, characterize the modes of action (MoAs) of stressors, develop in vitro and in vivo alternative testing strategies and in silico prediction tools for reducing laboratory animal tests.

Fig. 3: The Adverse Outcome Pathway (AOP) framework and multi-bio-level effect assessment. (You Song, NIVA).

Risk Assessment

Pulling all these techniques together enables a robust environmental risk assessment. In addition, the section performs standardized risk assessments for various international regulatory/legislative requirements (e.g. pharmaceuticals, veterinary medicine products, biocides, plant protection products, industrial chemicals etc.) using both the assessment factor approach and the species sensitivity approach. This provides environmental management authorities (e.g. the Norwegian Environment Agency, Norwegian Medicines Agency) with information on which to make decisions on how to manage chemicals in the environment. Over the years, the section for Ecotoxicology and Risk Assessment has conducted environmental risk assessments for a wide range of chemicals and chemical mixture for both regulatory authorities and external customers.

The Ecotoxicology and Risk Assessment section works closely with the Environmental Chemistry section who can supply full analytical support including LC-MS, GC-MS, GC-TOF-S and ICP-MS.

Several research scientists in the section are nominated experts on international panels such as ISO water quality working groups, OECD validation management groups for new and existing test guidelines, OECD non-animal testing, OECD endocrine disruptors, European Medicines Agency Committee for Veterinary Medicines Products Environmental Risk Assessment working party, NORMAN network, JPI Oceans Knowledge Hub -Integrated Assessment of Effects of New Pollutants, ICES Working group of Biological effects of Contaminants (WGBEC).



Last updated 14.09.2021