Multiple Objective Decision Analysis for Potassium Iodide Distribution
Multiple Objective Decision Analysis for Potassium Iodide Distribution in Nuclear Incidents L. Robin Keller Tianjun “Mike” Feng and Qiang “David” Zeng UC Irvine University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Multiple Objective Decision Analysis for Potassium Iodide Distribution in Nuclear Incidents A National Academy of Sciences book advises states and local jurisdictions to use a multiple objective decision analysis process to evaluate plans for distribution of potassium iodide (to protect against thyroid cancer) when there will be radioactive iodine exposure due to an accident or terrorism at a US nuclear power plant. The decision process features were proposed following public hearings involving multiple stakeholders with divergent political perspectives and varying assumptions about scientific evidence University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Health Risk If a nuclear incident (from an accident or terrorism) occurs and radioactive iodine is released … People exposed to the plume could have an increased risk of thyroid cancer due to inhalation – Young children & fetuses most at risk – Thyroid cancer is very rare for children, this could increase that risk, but it would still be quite rare (Thyroid gland is located beneath the voice box (larynx), produces thyroid hormone; helps regulate growth and metabolism) University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Disaster at Chornobyl Nuclear Power Plant in Ukraine in 1986 University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Chornobyl • People were not told of plant disaster for days, so exposed to plume and inhalation risks • Children and pregnant/nursing mothers ate leafy vegetables and drank milk from exposed cows over weeks, so received high doses of radioactive iodine from ingestion • All who later got thyroid cancer were ≤ 4 years old (including fetuses) at exposure • 3 thyroid patients died- 2 from bad anesthesia in surgery and 1 from parents not giving child thyroid pills (thyroid cancer highly treatable) University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Protective Measures Primary: Evacuate Secondary: Shelter in place to protect against all nuclear incident risks, not just radioactive iodine Supplemental: Take potassium iodide (KI) right before exposure to radioactive iodine to -“fill up thyroid” with stable iodine -block out radioactive iodine from getting into the thyroid University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
United States Nuclear Power • US Nuclear Power Plants are a different, safer design (compared to Chornobyl) • Assume ingestion pathway would be controlled in the US University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Process Background • Massachusetts Congressman Edward J. Markey’s law passed directing National Academy of Sciences to conduct a study on best way to distribute KI • National Research Council of National Academies received funding via Centers for Disease Control 1 1. Law 107 -188 sect. 127 University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Process Background, continued • Keller joined as decision analyst on committee of experts: – thyroid cancer physicians – radioactive safety experts – nuclear power plant safety – emergency management • Committee received oral or written public testimony from experts at agencies and organizations University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Timeline • May-Sept. 2003: Committee met monthly in DC (and once at UCI and Woodshole, MA offices of National Academy of Sciences) • Oct. 03: Book sent to external reviewers • Dec. 03: Prepublication briefings to agencies NRC, EPA, National Stockpile, FEMA) and to staff of Congressman Markey/Senate majority leader Bill Frisk, MD. • Dec. 03: Released to public http: //www. nap. edu University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Characteristics of Decision Problem • Political process calls for “scientific” perspective – Committee membership primarily experts on radiation, thyroid cancer, nuclear power plants: not policy experts • Discussion of KI separated from other ways to improve public health and safety • KI seen as the anti-nuke pill – as if it will protect everyone from all radiation for sure … framed as a “surething” • One side refuses to allow cost to be considered – Not-so-hidden agenda – get rid of nuclear power plants • Agency experts often said there is no one-size-fits-all solution University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Types of Alternative Actions • Predistribute to households, schools, hospitals, etc. – Via mail – Via voluntary pick up • Stockpile at evacuation reception centers • Do not pre-distribute University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Objectives Hierarchy a. 1. Maximize KI Availability a. 1. 1. Max. Availability for Children & Pregnant Women a. 1. 2. Max. Availability for Other Residents a. 1. 3. Max. Availability for Mobile Population a. 2. 1. Max. Number of People who Know Where Pill is A. Minimize Radioactive Iodine Risk to Thyroid a. 2. Optimize Ability to Take KI on Time a. 2. 3. KI is Taken at Optimal Time if Evacuation a. 2. 4. Ensure KI is Stored to Assure Stability a. 3. Minimize Harm from Inappropriate KI Administration MINIMIZE RADIATION HEALTH RISKS a. 2. 2. KI Taken at Optimal time if No Evacuation a. 3. 1. Correct KI Dose Given (and Taken) for Age a. 3. 2. First KI Dose Not Taken Too Late a. 3. 3. Adverse KI Side Effects (non-thyroid cancer) Minimized b. 1. KI Procedures Don’t Impede Evacuation B. Minimize Harm from Other Aspects of Incident b. 2. Avert Mortality and Morbidity from Radiation or Accidents b. 3. Minimize Panic/Anxiety due to KI Procedures b. 4. KI Procedures’ Resource Use Not Excessive b. 5. Simple KI Procedures before/during Incident b. 6. Educate Public to Respond to Nuclear Incident University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
• Note: minimizing cost is not an objective University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
See Excel spreadsheet • Use of sliders for weights on objectives • Gives “wiggle room” to see how different alternatives for KI distribution can be best in different situations University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Sample Display of Overall Value of Plans. Results Depend on Weights on Objectives and Planning Region University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Insights • Instead of choosing a specific location (like San Onofre, CA), we created 3 hypothetical regions (rural, suburban, urban) and showed how they might vary on their performance on the objectives University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Urban Site Example Minimize Radiation Health Risks to Public Relevant Characteristics of Urban Site Example A. Minimize Radioactive Iodine Risk to Thyroid a. 1. Maximize KI Availability a. 1. 1. Max. Availability for Children and Pregnant Women Residents 100, 000 -student school system a. 1. 2. Max. Availability for Other Residents Large resident population a. 1. 3. Max. Availability for Mobile Population increases by 25% from mobile workers a. 2. Optimize Ability to Take KI on Time a. 2. 1. Max. Number of People who Know Where Pill is Possible new residents won't be covered by earlier predistribution a. 2. 2. KI Taken at Optimal Time if No Evacuation Possible hurricane or ice storms might impede evacuation a. 2. 3. KI Taken at Optimal Time if Evacuation Delays possible if evacuation impeded by traffic or weather a. 2. 4. Ensure KI is Stored to ensure Stability KI might be stored in cars/wallets a. 3. Minimize Harm from Inappropriate KI Administration a. 3. 1. Correct KI Dose Given (and Taken) for Age a. 3. 2. First KI Dose Not Taken Too Late a. 3. 3. Adverse KI Side Effects (nonthyroid cancer) Minimized Large population of children Weather or traffic might impede evacuation to KI stockpile site Some pre-existing thyroid cases in large population of older adults or mobile workers B. Minimize Harm from Other Aspects of Incident b. 1. KI Procedures Don’t Impede Evacuation Transport network barely able to handle routine peak loads b. 2. Avert Mortality and Morbidity from Radiation or Accidents Transport network barely able to handle routine peak loads b. 3. Minimize Panic/Anxiety due to KI Procedures Large crowds possible b. 4. KI Procedures’ Resource Use Not Excessive Large population to cover for KI/predistribution and communication costs b. 5. Simple KI Procedures before and during Incident b. 6. Educate Public to Respond to Nuclear Incident Multiple nearby jurisdictions Emergency planning zone in one political jurisdiction *Assume all plans will stockpile KI at schools, hospitals, and jails in KI Planning Zone (KIPZ) University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Suburban Site Example Minimize Radiation Health Risks to Public Relevant Characteristics of Suburban Site Example A. Minimize Radioactive Iodine Risk to Thyroid a. 1. Maximize KI Availability a. 1. 1. Max. Availability for Children and Pregnant Women Residents Young families, expanding schools and day care, extensive busing a. 1. 2. Max. Availability for Other Residents Many working-age residents employed outside EPZ a. 1. 3. Max. Availability for Mobile Population Rapidly developing population, near major metro. area a. 2. Optimize Ability to Take KI on Time a. 2. 1. Max. Number of People who Know Where Pill is Possible new residents won't be covered by earlier predistribution a. 2. 2. KI Taken at Optimal Time if No Evacuation Occasional major snowstorms might impede evacuation a. 2. 3. KI Taken at Optimal Time if Evacuation Occasional major snowstorms might impede evacuation a. 2. 4. Ensure KI is Stored to ensure Stability KI might be stored in cars or wallets a. 3. Minimize Harm from Inappropriate KI Administration a. 3. 1. Correct KI Dose Given (and Taken) for Age a. 3. 2. First KI Dose Not Taken Too Late a. 3. 3. Adverse KI Side Effects (nonthyroid cancer) Minimized Large population of children Weather or traffic might impede evacuation to KI stockpile site Some pre-existing thyroid cases in older or retired residents B. Minimize Harm from Other Aspects of Incident b. 1. KI Procedures Don’t Impede Evacuation b. 2. Avert Mortality and Morbidity from Radiation or Accidents Transport network might not be able to handle peak loads Buses available for children, two interstates + rural two-lane roads b. 3. Minimize Panic/Anxiety due to KI Procedures Many day-care facilities, power plant second largest employer b. 4. KI Procedures’ Resource Use Not Excessive Moderate-size population to cover for KI predistribution and communication costs b. 5. Simple KI Procedures before and during Incident b. 6. Educate Public to Respond to Nuclear Incident *Assume all plans will stockpile KI at schools, hospitals, and jails in KI Planning Zone (KIPZ) University of California, Two counties Emergency planning zone in two counties Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Rural Site Example Overall Objectives Relevant Characteristics of Rural Site Example A. Minimize Radioactive Iodine Risk to Thyroid a. 1. Maximize KI Availability a. 1. 1. Max. Availability for Children and Pregnant Women Residents a. 1. 2. Max. Availability for Other Residents a. 1. 3. Max. Availability for Mobile Population Small schools, extensive busing, few children Very small resident population of 15, 000 in agricultural area Power plant largest employer in county a. 2. Optimize Ability to Take KI on Time a. 2. 1. Max. Number of People who Know Where Pill is Few residents a. 2. 2. KI Taken at Optimal Time if No Evacuation Unlikely winter snows or spring river flooding could block main roads a. 2. 3. KI Taken at Optimal time if Evacuation Unlikely winter snows or spring river flooding could block main roads a. 2. 4. Ensure KI is Stored to ensure Stability KI might be stored in leaky barns a. 3. Minimize Harm from Inappropriate KI Administration a. 3. 1. Correct KI Dose Given (and Taken) for Age/Body size a. 3. 2. KI Taken at Optimal Time a. 3. 3. Adverse KI Side Effects Minimized Small population of children Weather or traffic might impede evacuation to KI stockpile site Small Chance of pre-existing thyroid cases in middle-aged residents B. Minimize Harm from Other Aspects of Incident b. 1. KI Procedures Don’t Impede Evacuation b. 2. Avert Mortality and Morbidity from Radiation or Accidents Entire KIPZ can normally evacuate in < 3 hours Two-lane and farm roads b. 3. Minimize Panic/Anxiety due to KI Procedures School buses available for children; Power plant largest employer b. 4. KI Procedures’ Resource Use Not Excessive Small population to cover for KI predistribution and communication costs b. 5. Simple KI Procedures before and during Incident b. 6. Educate Public to Respond Appropriately to Nuclear Plant Incident One county jurisdiction Emergency planning zone in one county University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
Conclusions • Don’t aggregate to too high a level • Give decision makers “wiggle room” • Software with sliders allows real-time decision aiding and sensitivity analysis • Decision analysts can play a significant role in structuring consideration of major political issues by serving on National Academy committees University of California, Irvine Presentation in Decision Analysis Society Cluster at INFORMS Conference, Denver, Oct. 2004
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