ABSTRACT
This chapter discusses the basic principles of ecological risk assessment as well as the context within which these assessments are used. Ecological risk assessment can be thought of as a logical process which estimates the likelihood that undesirable ecological effects may occur or are occurring as a result of human activities. The basic concepts of ecological risk assessment are applicable to nonchemical stressors such as physical habitat alterations and changes in environmental conditions such as water temperature and pH. One of the emerging uses of both human health and ecological risk assessments is to set priorities for research and budget needs. The science that addresses the adverse ecological effects of xenobiotics is known as ecotoxicology. The ecological risk assessment process is conceptually similar to the National Research Council paradigm for human health in that both the potential effects and exposure of a chemical are assessed and the results integrated through risk characterization.
