3-1

Transition in EPA Human Health Risk-Assessment Characteristics According to EPA,

69

4-1

Examples of Factors Affecting Susceptibility to Effects of Environmental Toxicants,

109

5-1

Potential Approaches to Establish Defaults to Implement the Unified Framework for Dose-Response Assessment,

175

6-1

Examples of Explicit EPA Default Carcinogen Risk-Assessment Assumptions,

194

6-2

Examples of Explicit EPA Default Noncarcinogen Risk-Assessment Assumptions,

195

6-3

Examples of “Missing” Defaults in EPA “Default” Dose-Response Assessments,

196

7-1

Modified Version of Stressor-Based Cumulative-Risk-Assessment Approach from Menzie et al. (2007) Oriented Around Discriminating among Risk- Management Options,

222

C-1

Timeline of Selected EPA Risk-Assessment Activities,

284

D-1

Environmental Protection Agency Response to National Research Council Recommendations of 1983-2006: Policy, Activity, and Practice,

301

E-1

Nine Evaluation Criteria for Superfund Remedial Alternatives,

378

E-2

Examples of Default Exposure Values with Percentiles,

380