EPA has developed an air toxics risk assessment (ATRA) reference library for conducting air toxics analyses at the facility and community-scale. This library provides information on the fundamental principles of risk-based assessment for air toxics and how to apply those principles in different settings as well as strategies for reducing risk at the local level. A more detailed description of each volume of the ATRA library is provided below.

Volume 1: Technical Resource Manual

Volume 1 discusses the overall air toxics risk assessment process and the basic technical tools needed to perform these analyses. The manual, which covers both human health and ecological analysis, also provides a basic overview of risk management and communication. Other tools (such as the public health assessment process) are described to give assessors, risk managers, and other stakeholders a more holistic understanding of the many issues that may come into play during air toxics risk assessment and reduction projects.

Volume 2: Facility-Specific Assessment

Volume 2 builds on the technical tools described in Volume 1 by providing detailed procedures for source-specific or facility-specific risk assessments. Information is also provided on tiered approaches to source- or facility-specific risk analysis.

Volume 3: Community-Scale Assessment

Volume 3 builds on the information presented in Volume 1 to describe how to evaluate and reduce cumulative air toxics risks at the local level. The volume also discusses other multimedia risk factors that may affect communities, and strategies to reduce those risks.

Community Air Screening How-To Manual

The Community Air Screening How-To Manual provides a detailed step-by-by step guide to help community partnerships use one of the screening level approaches described in Volume 3 to understand and improve local outdoor air quality. The Manual explains how to form a partnership, clarify goals, develop a detailed source inventory, use a risk-based screening process to identify priorities, and develop options for reducing risks from priority sources and concentrations. The Manual provides a framework for bringing together technical staff and local residents to share information, deliberate, and build consensus on priorities for improving local air quality. The Manual places special emphasis on sharing information and providing the background education needed to insure that all members of the partnership can participate fully in key partnership decisions.

The ATRA library is an ongoing endeavor and may be revised periodically. EPA welcomes public input on the library at any time.