Assessing Risks to Populations at Superfund and RCRA Sites: Characterizing Effects on Populations (Final)

In July 2000, ORD's Ecological Risk Assessment Support Center (ERASC) received a request from the Ecological Risk Assessment Forum (ERAF) to provide insight to issues associated with site-specific ecological risk assessments involving populations. This request contained questions that have frequently been asked in the context of several regulatory programs and in efforts undertaken by natural resource trustees. These questions include:

• How should populations be defined?
• What should we measure to characterize populations?
• How do we make the connection between measurements made on individual organisms and population effects?
• How can we measure and interpret effects on natural populations?
• What spatial and temporal scales are appropriate when assessing risks to populations?

The final document addressing this request supports performance and interpretation of population-level risk assessments conducted at Superfund and RCRA sites by providing information relevant to the above questions. The focus of the document is strictly on issues relevant to characterizing effects on populations. It provides information that will help risk assessors to perform population-level risk assessments.

This is the final document.