Ecological Risk Assessment

Ecological Risk Assessment
By Mary Steffen-Deaton

What is Ecological Risk Assessment? Ecological Risk Assessment is a tool used in policy analysis. An Ecological Risk Assessment (ERA) may be performed to determine or estimate the possibility that potentially harmful effects could occur if exposed to a particular chemical or contaminant.

Similar to a risk assessment performed for human health, an ecological risk assessment determines or estimates potential risk to the environment if exposed to a chemical or contaminant through a qualitative (scientific judgment) and quantitative (scientific methods) process. The EPA has published documents that provide a list of guidelines for the risk assessment process. Framework for Ecological Risk Assessment (EPA/63-R-92/001) and Guidelines for Ecological Risk Assessment (EPA/630/R-95-002F) are the two documents that provide a description of the process of risk evaluation and EPA approved analytical methods. LaGrega discusses, in 14-7, four phases of Ecological Risk Assessment.

The Ecological Risk Assessment begins with the general and moves to the specific. The process starts with a screening process that gives a description of the setting, what chemicals exists already on site, are there known endangered or threatened species on site, and possible routes of environmental fate. This phase of the process provides a characterization of the initial site. This gives a description of what is already there before the introduction, (or possible introduction) of a contaminant or chemical.

The next phase is to determine the Ecological toxicity of the environment. Scientific information is used to make assessments based on known responses to particular chemicals. Modeling is a tool that can be utilized. Analytical methodology is used to determine toxicity. Scientific testing specific to the type of ecosystem media (terrestrial vs. aquatic) are performed to determine lethality.

Next the Potential Exposures routes are identified. This phase identifies all the possible potential exposure methods as well as intensity, frequency, and duration of exposure.

Finally, the risk characterization is the phase that combines all the information learned in the previous phases to pose an estimation of the risk and risk description. All the analytical testing are analyzed and then grouped with scientific judgment to create a characterization of the risk.

References:

Lackey, Robert T. Challenges to Using Ecological Risk Assessment to Implement Ecosystem Management, Environmental Effects Research Laboratory, Corvallis, Oregon

LaGrega et al. Hazardous Waste Management, 2nd ed., p. 865-906.

U.S. EPA. ECO-Update, Catalogue of Standard Toxicity Tests for Ecological Risk Assessment, Publication 9345.0-05l, March 1994.

U.S. EPA. Framework For Ecological Risk Assessment. http://www.epa.gov/raf/publications/pdfs/FRMWRK_ERA.PDF

U.S. EPA. Guidelines for Ecological Risk Assessment, U.S. Environmental Protection Agency, Risk Assessment Forum, Washington, DC, EPA/630/R095/002F, 1998. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=12460