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Rich Williams NASA Chief Health and Medical Officer. Mission to Mars: Health Risk Mitigation. Societal Imperatives. National Security Imperative Public Safety Imperative Human Exploration Imperative. Risk Mitigation in an Occupational Environment. Crew selection standards
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Rich Williams NASA Chief Health and Medical Officer Mission to Mars:Health Risk Mitigation
Societal Imperatives • National Security Imperative • Public Safety Imperative • Human Exploration Imperative
Risk Mitigation in an Occupational Environment • Crew selection standards • Waivers are routine • Engineering controls • Exposure limits standards • In general, no waivers granted • Personal protection, countermeasures • Medical/environmental monitoring
vacuum vacuum Risks: The Space Environment temperatureextremes Isolation &confinement 1 yr mg Water & food availability circadian 49,000,000 km New geo-ecosystem 22 minute 1-way communication Reduced gravity Fuel & oxygen Biorhythms? mg 1 yr Radiation temperatureextremes Isolation &confinement
Space Flight Experience (continuous) Flights longer than 28 days (May 1973 - June 2012) Most long-duration flights are 4-7 months long Number of Exposures Mars missions may last up to 30 months 30 Flight Duration (months)
Time Course of Physiological Changes in Weightlessness
Mars Radiation Exposure Comparing Solar Max and Solar Minimun 1 Sv = ~ 100 Rem Person at Sea level ~ 1.4 Rem/yr ISS Crew member ~ 5.4 Rem/6 months Mars Crew member ~20-85 Rem
Visual Impairment/Elevated Intracranial Pressure Background: 19 known “clinical cases” of 25 evaluated crew members Each with different degrees of symptoms • Choroidal Folds - parallel grooves in the posterior pole • Hyperopic Shifts • -Up to +1.75 diopters • Optic Disc Edema (swelling) • Globe Flattening • Altered Blood flow • “cotton wool” spots • Increased Optic Nerve Sheath Diameter MRI Orbital Image showing globe flattening Normal Globe Flatten Globe 8
Behavioral Health Seeing Earth through a telescope from Mars Earth and Jupiter from the Martian surface
NASA Health and Medical Policies • NASA ground workforce health and safety is regulated by OSHA • Executive Order 12196, February 26, 1980, Occupational Safety and Health Programs for Federal Employees • NASA environmental health issues are regulated by EPA • NASA public use vehicle operations (research aircraft, spacecraft) are controlled by NASA policy directives, procedural requirements, standards and requirements • NASA health and medical policies and standards “regulate” aircrew and space flight crew selection, qualification, and health related requirements in NASA research aircraft and spacecraft
NASA Health Standards for Human Spaceflight • NASA STD-3001 Vol. 1: NASA Space Flight Human System Standard - Volume 1: Crew Health • 4.2.3 Fitness-for-Duty Aerobic Capacity Standard • 4.2.4 Fitness-for-Duty Sensorimotor Standard • 4.2.5 Fitness-for-Duty Behavioral Health and Cognition Standard • 4.2.6 Fitness-for-Duty Hematology and Immunology Standard • 4.2.7 Permissible Outcome Limit for Nutrition Standard • 4.2.8 Permissible Outcome Limit for Muscle Strength Standard • 4.2.9 Permissible Outcome Limit for Microgravity-Induced Bone Mineral Loss Performance Standard (Baseline with Measured Tscore) • 4.2.10 Space Permissible Exposure Limit for Space Flight Radiation Exposure Standard
Ethical Considerations of Exploration Class Missions • Exceeding exposure limits is justified only if the benefit to the population is greater than the risk to the individual • Examples: • Radiation workers can exceed exposure limits to contain nuclear power plant contingencies • Generally defined in the radiation exposure standards • Military members can exceed radiation dosage limits if driven by necessity
Ethical Considerations of Exploration Class Missions • How do we approach increased health risks for exploration class missions? • Liberalize exposure limits for exploration class missions • Waive exposure standards for exploration class missions • Administrative risk acceptance by higher authorities • Informed consent? • How is health risk acceptance influenced by overall mission risk?
National Academies:Institute of Medicine • Committee on Aerospace Medicine and the Medicine of Extreme Environments (CAMMEE) • Ethics, Principles and Guidelines for Health Standards for Long Duration and Exploration Spaceflights
Institute of Medicine Study • What factors should be considered in the implementation of current health standards in exploration class missions? • What ethical considerations are involved when exposures/risks are uncertain and exposures may exceed current standards? • How should informed consent be applied? • What are appropriate modifiers for standards when risks/exposures are uncertain? • Should all crewmembers be protected to the same extent or should potential individual differences be considered? • Are there models or examples that could inform NASA strategy?
NASA Policy Formulation • Federal Government Policy • Statutes, Regulations, Executive Orders/Presidential Directives • NASA Agency Policy • NASA Policy Directives • NASA Procedural Requirements • NASA Standards • Plans, Requirements • Programmatic (Space Shuttle, International Space Station) • Project (External Tank, Shuttle Main Engines, etc) • Mission Support
NASA Internal Regulation • Established by the National Aeronautics and Space Act of 1958 “To provide for research into problems of flight within and outside the earth's atmosphere, and for other purposes.” • 51 USC 20113(a): In the performance of its functions the Administration is authorized-- • (1) to make, promulgate, issue, rescind, and amend rules and regulations governing the manner of its operations and the exercise of the powers vested in it by law; • The NASA Administrator is authorized to promulgate internal NASA policies governing operations within the Agency • Health and medical policy formulation, promulgation, and oversight is delegated to the Chief Health and Medical Officer
NASA Health Standards for Human Spaceflight • “In this document, the Office of the Chief Health and Medical Officer establishes NASA’s space flight crew health standards for the pre-flight, in-flight, and post-flight phases of human space flight.” • “Although the standards are applicable to the in-flight phase of all space missions, it is anticipated that they will be most relevant during long-duration lunar outpost and Mars exploration missions, since the combined ill effects of exposure to the space environment will be of most concern in those mission scenarios.”