A framework for ecological risk assessment at the EPA

Abstract Ecological risk assessments evaluate the likelihood of adverse ecological effects caused by stressors related to human activities such as draining of wetlands or release of chemicals. The term stressor is used to describe any chemical, physical, or biological entity that can induce adverse effects on ecological components (i.e., individuals, populations, communities, or ecosystems). In this review article, a historical perspective on ecological risk assessment activities at the U.S. Environmental Protection Agency (EPA) is followed by a discussion of the EPA's “Framework Report,” which describes the basic elements for conducting an ecological risk assessment. The “Framework Report” is neither a procedural guide nor a regulatory requirement within the EPA. Rather, it is intended to foster a consistent approach to ecological risk assessments within the Agency, identify key issues, and define terminology.