State of the Science in Ecological Risk Assessment

Virginia H. Dale
Department of Energy Oak Ridge National Laboratory

Ecological risk assessment (ERA) has been practiced for approximately 20 years in a variety of environmental applications.  At a recent workshop sponsored by the Environmental Protection Agency, researchers and practitioners came together to discuss their cumulative experience, and suggest steps for improving the utility of ecological risk assessments in environmental decision-making.  Workshop participants addressed ecological risk assessments in three decision-making contexts:  product health and safety; management of contaminated sites, and natural resource protection.  For each of the three decision-making applications, workshop participants evaluated four over-arching issues:  problem formulation and hypothesis testing; spatial and temporal scale; biological scale; and decision-making in the presence of uncertainty.   The workshop participants came to several conclusions.  Problem formulation is a critical step in ERA and requires:  improved communication between risk managers and risk assessors; careful consideration of critical ecological attributes; and moving beyond traditional null hypothesis testing and toward innovative analytical approaches (e.g., Bayesian analysis, causal argumentation).  Current methods are available to conduct ERA’s at different spatial, temporal and biological scales.  However, effective implementation of landscape level ERA’s requires more relevant data and explicit guidance to better integrate multiple lines of evidence for a range of biological responses.  The utility of ERA’s for decision-making can also be increased by:  probabilistic risk assessment methods that include quantitative uncertainty estimates.  Finally, the uncertainty associated with ERA’s will also be assisted by systematic approaches in post-ERA monitoring, and data collection and storage.

corresponding author:
Virginia H. Dale                       
Oak  Ridge National Laboratory    
Bethel Valley Road, Building 1505, Room 200
P.O. Box 2008
Oak Ridge, TN 37831-6036
865-576-8043
dalevh@ornl.gov

note: oral presentation only