Risk modelling

Environmental Risk Assessment (ERA) has become a generally used tool in the evaluation of the potential environmental impact of chemical products or activities. Since the late eighties, IMARES is active in environmental risk assessment. As such, we are and have been involved in the development of methods and standards which are currently used for regulatory and scientific purposes.

Tiered approach
Our application of risk assessment models nearly always follows a tiered approach in order to balance required detail and effort:

1. PEC: PNEC risk screening based on worst-case assumptions on sensitivity and exposure.
2. Probabilistic risk assessment; this approach uses the same type of input data as used in the PEC:PNEC approach but results in a more quantified risk estimate (probability that a species is exposed above its chronic NOEC).
3. Biology based risk assessment; uses the state of the art knowledge on biology, ecology, and toxicology and integrates principles to estimate effects on key species (individuals and populations), food chains, and ecosystems

It is obvious that the higher the tier of the risk assessment, the more specific the information needed on species, systems and toxic properties. Hence, there must be a justification for such a tiered approach that can be found in the area or of the stressor of concern. The higher the tier in risk assessment, the more comparable the results are to the results of monitoring; quantifying severity and extent of biological effects.

New developments
IMARES is very active in the further development of environmental risk assessment methods to suit the needs of the future. Our developments include:

1. Cumulative Effects Assessment. The relevance of cumulative effects is recognized world wide. Despite all efforts, however, a common understanding of cumulative effects assessment is still lacking. IMARES is engaged in several studies to increase the understanding of this complex issue.
2. Integrated environmental risk assessment consists of an combined evaluation of environmental impact on the basis of both risk assessment modeling and environmental monitoring. We developed a framework (Figure) for development of both risk modeling and effect monitoring into a more realistic an sophisticated endpoint for impact assessment.
3. Biomarkers in risk assessment is an actual challenge that we have taken up for development recently. The biomarker approach in environmental monitoring is getting increasingly more attention as it provides an early indication of potential damage to an organism. Using biomarkers in risk assessment methods may close the gap between modeling and monitoring.
4. Integration of Health, Safety and Environmental risk assessment. Recent studies and reports (including the world health organization) have demonstrated that an integrate HSE approach is needed to make correct decisions in the optimization of an activity concerning H, S and E. The crucial step in the integration of risks is the harmonization of the risk assessment endpoints for all HS&E topics.