To gain insight into the process of ecological risk assessment, scientists from the U.S. Environmental Protection Agency (EPA) have analyzed a cross-section of case studies representing the 'state-of-the-practice' in ecological assessment. The 12 case studies are wide-ranging in scope, representing a variety of ecosystems, ecological endpoints, chemical and non-chemical stressors, and programmatic requirements within the Agency. As a result, workshop participants were presented with a broad diversity of risk assessment and scientific issues, and many useful principles emerged from the resulting discussions. The case studies report provides a useful first look at some common approaches to ecological assessment in relationship to a general ecological risk process. The cases selected were evaluated at the workshops as to whether they (1) effectively addressed generally accepted components of an ecological risk assessment, or (2) addressed some but not all of these components or, instead, (3) provided an alternative approach to assessing ecological effects. The analysis and discussion in the report provide useful information about ecological risk processes.

Report prepared by William van der Schalie and Ronald Landy of the EPA, and Charles Menzie of Menzie-Cura & Associates, Inc. "May 1993"--Vol. 1. "July 1994"--Vol. 2. Vol. 1 contains evaluations of twelve case studies based upon a series of EPA-sponsored workshops held between May 29, and June 20, 1991. Vol. 2 contains evaluations of five case studies based upon two EPA-sponsored workshops held in September 1992. Contract no. 68-C1-0030. Includes bibliographical references.