Papers in the Biological Sciences


Date of this Version



Published in Integrated Environmental Assessment and Management 6 (2010), pp. 191-193.


Current approaches to ecological risk assessment (ERA) are not sufficient to address environmental protection goals stated in current regulations in the European Union, North America and elsewhere. For example, the data used to estimate the likelihood of adverse ecological effects typically include responses of survival, growth, or reproduction of individuals measured under constant and typically favorable laboratory conditions. But these organism-level endpoints are far removed from the ecological features that the process aims to protect (i.e., the long-term persistence of populations of species in space and time under naturally varying field conditions and in the presence of other stressors). Ecological risk is most often characterized as a hazard ratio of predicted or measured exposure to predicted no-adverse-effect level expressed as a concentration or dose. It is widely accepted that such hazard ratios provide useful screening tools when exposure and no-effect levels are calculated using appropriately conservative assumptions. However, such ratios suffer from several disadvantages, not the least of which is that their relationship to the likelihood and degree of ecological impacts (i.e., risk) is unknown.

Risk assessments only make sense if they inform management decisions about if, how, and how much we need to intervene in economic activities such as the production, use, and disposal of chemicals, to protect nature. The ecological protection goals are specified imprecisely in the legal instruments implementing environmental protection policies and are supposed to reflect public preferences, i.e., what the public values. Because environmental interventions invariably involve restrictions to economic activities, they involve costs; it is, therefore, important to judge these in terms of the value put on the ecological systems and related ecosystem services saved by the intervention. These kinds of socioeconomic analyses are mandated in chemicals legislation in the European Union, North America, and other jurisdictions.