Overview: Use of Results

The results of this national screening-level assessment will provide important information to help us continue to develop and implement various aspects of our national air toxics program, but they will not be used directly to regulate sources of air toxics emissions. While regulatory priority setting will be informed by this and future national screening-level assessments, risk-based regulations will be based on more refined and source-specific data and assessment tools.

More specifically, these initial assessment results will help to:

• Identify air toxics of greatest potential concern.
• Characterize the relative contributions to air toxics concentrations and population exposures of different types of air toxics emissions sources.
• Track trends over time in ambient concentrations of air toxics.
• Measure progress toward meeting goals for reduction of risks from ambient air toxics.
• Set priorities for the collection of additional air toxics data to improve estimates of air toxics concentrations and their potential public health impacts. Important additional data collection activities will include upgraded emission inventory information, ambient air toxics monitoring, and information on adverse effects to health and the environment.