classes of agents, including enhanced or engineered agents that have yet to be developed; and

• Discuss in more detail beyond the first report the feasibility of extending the methodology to also serve as a framework for risk analysis of chemical or radioactive threats.

In January 2006, the Office of Management and Budget (OMB) issued technical guidance for risk assessment. A report from the National Research Council (NRC, 2007) entitled Scientific Review of the Proposed Risk Assessment Bulletin from the Office of Management and Budget identified, in the OMB guidance, many of the same problems cited in the present report: unclear technical definitions, improper uncertainty analysis and use of expected values, and poorly conceived consequence analysis. The present report recommends technical and process improvements that are intended to make DHS risk assessment methodology more understandable, more credible, easier to communicate, and both defensible and useful at every major decision-making point in a comprehensive and effective risk management system.

In Chapter 2 the committee examines the broader context of the risk assessment methodology; in Chapter 3 it examines the implementation of the BTRA by the Battelle Memorial Institute, Columbus, Ohio; and in Chapters 3 through 7 the committee recommends improvements in the methodology. The report’s 13 appendixes provide the following:

• A: A lexicon containing the technical terms used in this report;

• B: A concise mathematical description of the 2006 BTRA event tree;

• C: A numerical example illustrating the simplification of probability assessment;

• D: An alternative model for risk assessment using decision trees:

• E: An alternative model for risk assessment using mathematical optimization;

• F: An alternative model and example of risk assessment using game theory;

• G: A discussion of alternative means to quantify uncertainty;

• H: A discussion of the role of interdependencies in managing risk;

• I: An independent review of the BTRA of 2006;

• J: A reprint of the committee’s interim report;

• K: The meeting agendas of the committee;

• L: Biographies of committee members; and

• M: A list of acronyms used in this report.

In the committee’s view, it is imperative that the bioterrorism threat risk assessment be used to facilitate a coherent strategy of risk management against a grave and growing threat to U.S. security. The committee believes that its work will assist the federal government, as a top priority, to mature the DHS risk assessment methodology as the foundation of risk management by all the relevant stakeholders.

Congressional Research Service. 2003. The Biowatch Program: Detection of Terrorism. Report RL32152. Available at www.fas.org/sgp/crs/terror/RL32152.html#_1_1. Accessed July 23, 2007.

DHS (Department of Homeland Security). 2006. Bioterrorism Risk Assessment. Biological Threat Characterization Center of the National Biodefense Analysis and Countermeasures Center. Fort Detrick, Md.

Drell, Sidney D., Abraham D. Sofaer, and George D. Wilson (eds.). 1999. The New Terror: Facing the Threat of Biological and Chemical Weapons. Stanford, Calif.: Hoover Institution Press.

Homeland Security Council. 2004. “Scenario 2: Biological Attack—Aerosol Anthrax,” in Planning Scenarios. July. Available at www.globalsecurity.org/security/library/report/2004/hsc-planning-scenarios-jul04.htm#toc. Accessed November 14, 2007.

National Intelligence Council. 2004. Mapping the Global Future: Report of the National Intelligence Council’s Project Based on Consultation with Nongovernmental Experts Around the World. Washington, D.C.: U.S. Government Printing Office.

Negroponte, John D. 2007. Annual Threat Assessment (unclassified for the Record). Testimony before the Senate Select Committee on Intelligence. U.S. Senate. Washington, D.C. January 11.

NRC (National Research Council). 2007. Scientific Review of the Proposed Risk Assessment Bullet in from the Office of Management and Budget. Washington, D.C.: The National Academies Press.

Office of Homeland Security. 2002. National Strategy for Homeland Security. Available at www.dhs.gov/xlibrary/assets/nat_strat_hls.pdf. Accessed November 1, 2006.

U.S. Commission on National Security in the 21st Century. 1999. New World Coming: American Security in the 21st Century. Washington, D.C.: U.S. Government Printing Office.

The White House. 2004. Homeland Security Presidential Directive 10 [HSPD-10]: Biodefense for the 21st Century. Available at www.fas.org/irp/offdocs/nspd/hspd-10.html. Accessed January 16, 2008.

The White House. 2006. National Strategy for Combating Terrorism. Available at www.state.gov/s/ct/rls/wh/71803.htm#overview. Accessed July 23, 2007.

The White House. 2007. Homeland Security Presidential Directive 18 [HSPD-18]: Medical Countermeasures Against Weapons of Mass Destruction. Available at www.fas.org/irp/offdocs/nspd/hspd-18.html. Accessed January 16, 2008.

WMD Commission (Commission on the Intelligence Capabilities of the United States Regarding Weapons of Mass Destruction). 2005. The Report on the Intelligence Capabilities of the United States Regarding Weapons of Mass Destruction. Available at www.wmd.gov/report. Accessed January 16, 2008.