What Are the Qualities of an Effective Risk Characterization? (Text Version)

An effective risk characterization provides clear information to risk managers in order to be useful for environmental decision-making. The characterization should express results clearly, articulate major assumptions and uncertainties, identify reasonable alternative interpretations, and separate scientific conclusions from policy judgments. Depending on the situation, effective risk characterization may be organized differently, be simple or complex, and may be long or short; regardless, but it will accomplish the following objectives.

Estimates the Risk

• Is it acute or chronic?
• What is the severity of effects?
• What is the time over which they occur?
• Is the risk to one species or many species?
• How many organisms?

Describes the Risk

• Will it affect the population overall?
• Will there be secondary effects that will affect another organism (e.g., loss of a prey species)?
• Is there a source of immigrants to replace lost organisms?

Links to Assessment Endpoints and Conceptual Model

• If we chose a surrogate species, can we link the risk back to the assessment endpoint?
• Does the risk characterization describe the circumstances in the conceptual model?

Easily Communicates with the Audience

• Is it clear? Transparent?
• Is it reasonable?
• Is it consistent throughout?

Documents Uncertainties

• Does it indicate a degree of confidence?
• Does it address data adequacy?