Human spaceflight is inherently risky, with numerous potential hazards posed at each phase of a mission. Potential health risks during spaceflights include short-term health consequences from being in microgravity, as well as long-term health consequences that arise, or continue, months or years after a flight. Additional health considerations are risks posed by exposure to environmental contaminants onboard spacecraft. Because the International Space Station and spacecraft are closed environments that require recirculation of air and water supplies, some contamination of the air and water will occur. Even with onboard air and water purification systems, chemicals will accumulate in the air and water as they recirculate or are recycled onboard. Therefore, it is necessary for the National Aeronautics and Space Administration (NASA) to identify hazardous contaminants and determine exposure levels that are not expected to pose a health risk to astronauts.

NASA uses spacecraft maximum allowance concentrations (SMACs) and spacecraft water exposure guidelines (SWEGs) to provide guidance on acceptable exposures to air and water contaminants during normal operations and emergency situations. Refinements to the Methods for Developing Spacecraft Exposure Guidelines updates the methods for establishing SMACs and SWEGs and assists NASA with identifying chemicals that need updated SMACs or SWEGs and new chemicals for which these guidelines should be developed.

Contents

• The National Academies of SCIENCES • ENGINEERING • MEDICINE
• COMMITTEE ON SPACECRAFT EXPOSURE GUIDELINES
• BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY
• OTHER REPORTS OF THE BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY
• Preface
• Summary
  • REFINING THE PROCESS OF DEVELOPING EXPOSURE GUIDELINES
  • SELECTING AND PRIORITIZING CHEMICALS
• 1. Introduction
  • THE PROCESS OF DEVELOPING AND REVIEWING SMACS AND SWEGS
  • ADVANCEMENTS IN RISK ASSESSMENT
  • STATEMENT OF TASK
  • APPROACH TO THE STUDY
  • ORGANIZATION OF THE REPORT
  • REFERENCES
• 2. Derivation of SMACs and SWEGs
  • EVIDENCE IDENTIFICATION AND INTEGRATION
  • DERIVING SMACs AND SWEGs
  • EXPOSURE CONSIDERATIONS
  • UNCERTAINTY FACTORS
  • SPACEFLIGHT FACTORS
  • MIXTURES
  • FINDINGS AND RECOMMENDATIONS
  • REFERENCES
• 3. Selecting and Prioritizing Contaminants for Assessment
  • FINDINGS AND RECOMMENDATIONS
  • REFERENCES
• APPENDIXES
  • Appendix A. Biographical Information on the Committee on Spacecraft Exposure Guidelines
  • Appendix B. Example Report Outlines for Future SMAC and SWEG Documents

Suggested citation:

The National Academies of Sciences, Engineering, and Medicine. 2016. Refinements to the Methods for Developing Spacecraft Exposure Guidelines. Washington, DC: The National Academies Press. doi: 10.17226/21888.