2008 DHS Bioterrorism Risk Assessment: Planned Improvements

1. 2008 DHS Bioterrorism Risk Assessment: Planned Improvements Traci Hale, Battelle Memorial Institute Committee on Methodological Improvement to the Department of Homeland Security’s 2006 Bioterrorism Risk Assessment 10 February 2007

2. General overview of plans • The 2008 Risk Assessment will include: • An expanded list of agents to be assessed (to include anti-agricultural, engineered, and emerging agents) • An expansion of scenarios for each target-type and associated revisions to the Event Tree • Review and improvement of all consequence models • Improved data regarding mitigation strategies, and improved medical mitigation models • Improved calculation engine to decrease run times and simplify configuration files • Implementation of formalized elicitation process to obtain SME judgments in specific subject areas • Expansion of economic modeling to include indirect costs as well as additional direct costs • Expansion of tailored risk assessments and sensitivity studies

3. Dissemination Efficiency Agent Release Modeling Agent Mass Mitigation Response Disease Spread RISK Threat Group Target Agent Production AGENT RELEASE Dispersion Mitigation Scenario Consequences Bioagent Scenario Probability Agent Risk Ranking Selection Probability Selection Probability Selection Probability Event Detection Initiation Frequency Event Tree Quantification Scenario Analysis and Consequence Modeling

4. Branch Probabilities and Uncertainty Management

5. Consequence Uncertainty • For the 2006 Risk Assessment epistemic uncertainty in the consequence results was not considered • Aleatory uncertainty, reflecting variation in results arising from unknowable details of bioterrorism attack scenarios, was embedded in the consequence models • Aleatory uncertainty is reflected in the scenario specific consequence distributions • Consequence uncertainty was omitted due to the overwhelming processing requirements

6. Consequence Uncertainty • For the 2008 Risk Assessment epistemic uncertainty in consequence results will be implemented • Improvements in the risk assessment software allowing specification of user defined functions that accept uncertainty parameters for components of the consequence calculation are the required improvement. For example: • Number of illnesses conditional on threat organization, target, surrogate, and mode of dissemination, [RI|MRE,TO,Target,Surrogate,ModeD,<uncertainty parameters>] • Percentage of fatalities mitigated by public health response conditional on number of illnesses, target, and event detection, [MFI|CI, Target, EventDetect, <uncertainty parameters>] • Moving Risk Assessment computing to a Linux cluster platform was required to make the computations required for consequence uncertainty feasible

7. Consequence Calculation Equations

8. Subject Matter Expert and Stakeholder Interactions

9. Subject Matter Experts and Stakeholder Interactions • Subject Matter Expert / Stakeholder interactions are taking several forms: • Formal elicitations • START (bioagent selection probabilities) • Selected psychologists from the IC (bioagent selection probabilities) • BTISWG (interdiction, frequency of initiation, bioagent selection, multiple attack probabilities) • Informal elicitations • BTISWG panel discussion of target, dissemination, and production probabilities • Stakeholder Working Group meetings • IBRAWG (review and vet attack scenarios, production data, medical mitigation data)

10. Subject Matter Experts and Stakeholder Interactions • IBRAWG • Includes CDC, NIH, FDA, USDA, EPA, and the intelligence community, • created to “provide interagency input guidance and to the DHS BTRAP. This Working Group will assist DHS in identifying agents and scenarios for the 2008 Bioterrorism Risk Assessment and will provide technical review of risk assessment input and assumptions, establishing subgroups for this purpose if necessary. The IBRAWG will be a source of technical advice and expertise, and will serve as an interagency forum for sharing, reviewing, and vetting risk assessment data and results as they are generated.” • To date, this group has been responsible for the selection of the 2008 biological agent list, has provided input for attack scenarios, and has provided significant contributions which will play a role in consequence and mitigation modeling. • BTISWG • Includes members of the intelligence community • created for the express purpose of providing classified intelligence/threat information and data to the Risk Assessment. This group will be responsible for the assignments of probability concerning terrorist decisions through both formal Subject Matter Expert elicitations as well as informal discussions.

11. Subject Matter Experts and Stakeholder Interactions • These Working Groups provide the stakeholders with the opportunity to • review and discuss attack and mitigation input scenarios and input data • reach consensus regarding broad spectrum issues (such as selection of the 2008 bioagent list) • voice any issues or concerns regarding the assessment while still in progress

12. Indoor Aerosol Dispersion Modeling

13. Indoor Aerosol Dispersion Modeling • In October 2006, the release of a biological agent in a subway system was specifically identified by DHS as a high priority attack scenario to address • In the 2006 assessment, the subway attack scenario was considered, but only as one of several small enclosed building surrogates • For the 2008 assessment, the subway (and other surrogates) will be individually assessable on the Event Tree • The model for the subway attack scenario will include the transfer of biological agent from the point of dissemination to additional downstream subway stations via movement of air in the subway cars and through the tunnels

14. Foodborne and Waterborne Contamination Modeling

15. Foodborne and Waterborne Contamination Modeling • Food Contamination Assessment • Joint efforts are being initiated with BTSafety • BT Safety is participating in a collaborative effort with several federal agencies, including FDA, USDA, CDC and DHS NCFPD to develop a simulation model to estimate the impact of food supply contamination • This model is planned to be modified and incorporated into the DHS Risk Assessment calculation engine

16. Foodborne and Waterborne Contamination Modeling • Water Contamination Assessment • Joint efforts are being initiated with EPA • To generate a more realistic decay model • To calculate a more accurate mixing parameter based on comparisons of the Risk Assessment mathematical model with EPA-held hydraulic models of real public water systems • Continuing discussions with EPA staff regarding other aspects of the Water Contamination scenarios, including building system contamination and post-attack decontamination • Stakeholder input (FDA, USDA, NCFPD, EPA) is considered critical to a successful assessment

17. Medical Mitigation and Epidemiological Modeling

18. Medical Mitigation and Epidemiological Modeling • Substantial changes are in progress for the modeling of the public health response and spread of contagious diseases following a bioterrorism event • As described yesterday, SEIR modeling is being applied • Model and data review • In late February, a review of the SEIR model and input data will be performed by experts identified by DHS. • In early March, IBRAWG members will review models and input data as well • Risk perception • The SEIR model incorporates effects of ‘worried well’ • Impacts on available supplies • time to treatment due to increased distribution times

19. Anti-agricultural Scenarios

20. Anti-agricultural Scenarios • Joint efforts with Lawrence Livermore National Laboratories and Texas A&M • LLNL MESA model • Texas A&M FAZD model • Incorporates stakeholder input from • USDA (APHIS, ARS, CREES) • DHS • FAZD • LLNL BKC

21. Economic Analysis

22. Economic Analysis • Economic consequences are significantly affected by the impact of risk perception on human behavior • CREATE (primarily Adam Rose, Peter Gordon, Jim Moore, and Bumsoo Lee) collaborating on development of I-O models to capture bioterrorism attack economic impacts • CREATE (primarily Adam Rose) developing CGE models for a small set of surrogates to compare with I-O models

23. Economic Analysis • Direct Costs: • Economic models have four components: • Human health (Agent specific) • Hospitalization, treatments, etc. • Fatalities • One year of lost final demand • Decontamination (Agent and surrogate specific) • Lost usage of buildings, clean-up, animal disposal • ‘Conceptual model’ (Agent and surrogate specific) • Risk perception based losses, e.g., reduced air travel after airport or airplane attacks

24. Economic Analysis • Indirect Costs: • Fatality and conceptual model costs implemented in I-O primarily by reductions in final demand. • Some specific surrogates (for example, Mall) transfer demand from industry impacted (for example, Clothing and Entertainment) to another industry (for example, On-line shopping) • Human health and decontamination costs are assumed to be funded by the government • Positive impacts to medical and decontamination industries, • Non-defense government spending is reduced (budget cuts) and household spending is reduced (taxes) to pay for public health response and decontamination.

25. Tailored Risk Assessments and Sensitivity Studies

26. Tailored Risk Assessments and Sensitivity Studies • Increased capacity for tailored assessments and sensitivity studies • Faster computing through hardware upgrades and software improvements • Example tailored assessments requested • Use of high Ro agent, similar to measles • Injection of high expertise terrorists • Example sensitivity studies under consideration • Impact of additional modeling detail • Water modeling using a hydraulic simulation of a public water system versus the analytical model

27. Calculation Engine Improvements to Enable Quick-turn around Tailored Assessments • Speed Improvements: • Movement of code from .Net C# to ANSI standard C/C++ • Gets rid of .Net overhead • Porting of code from Windows to Linux • Gets rid of Windows overhead • Parallelizing code • Employs multiple processors to perform calculations more quickly • Conceptual Improvements: • Configuration files redesigned • Better mapping of component consequence distributions to all scenarios to which they apply • Development of user routines • More convenient drawing of consequence components from distributions conditional on other consequence components and uncertainty parameters • Compartmentalizing intermediate consequence calculations • Speeds tailored risk assessments and sensitivity studies by allowing computations to start from point at which results change

28. 2008 Bioterrorism Risk Assessment Planned Improvements Associated with NAS Issues • *Data updating approach • Data replacement and Bayesian updating • Stakeholder/SME Interactions • Bioagent selection, scenario definition, model and data review, direct elicitation input • *Standardize lexicon • *Non-traditional agents • *Data quality matrix • Incorporation of risk perception • Indirect costs and worried well • Sensitivity Studies • Performed based on specific DHS requests or to further investigate internally-identified areas of interest * indicates activities which will be discussed in detail during the NAS response discussions