A Native American exposure scenario.

EPA's Risk Assessment Guidance for Superfund (RAGS) and later documents provide guidance for estimating exposures received from suburban and agricultural activity patterns and lifestyles. However, these methods are not suitable for typical tribal communities whose members pursue, at least in part, traditional lifestyles. These lifestyles are derived from a long association with all of the resources in a particular region. We interviewed 35 members of a Columbia River Basin tribe to develop a lifestyle-based subsistence exposure scenario that represents a midrange exposure that a traditional tribal member would receive. This scenario provides a way to partially satisfy Executive Order 12,898 on environmental justice, which requires a specific evaluation of impacts from federal actions to peoples with subsistence diets. Because a subsistence diet is only a portion of what is important to a traditional lifestyle, we also used information obtained from the interviews to identify parameters for evaluating impacts to environmental and sociocultural quality of life.