Methods For Developing Spacecraft Water Exposure Guidelines

The National Aeronautics and Space Administration (NASA) maintains an active interest in the environmental conditions associated with living and working in spacecraft and identifying hazards that might adversely affect the health and well-being of crew members. Despite major engineering advances in controlling the spacecraft environment, some water and air contamination appears to be inevitable. Several hundred chemical species are likely to be found in the closed environment of the spacecraft, and as the frequency, complexity, and duration of human space flight increase, identifying and understanding significant health hazards will become more complicated and more critical for the success of the missions. NASA asked the National Research Council (NRC) Committee on Toxicology to develop guidelines, similar to those developed by the NRC in 1992 for airborne substances, for examining the likelihood of adverse effects from water contaminants on the health and performance of spacecraft crews. In this report, the Subcommittee on Spacecraft Water Exposure Guidelines (SWEGs) examines what is known about water contaminants in spacecraft, the adequacy of current risk assessment methods, and the toxicologic issues of greatest concern.

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.

The International Space Station is a closed and complex environment, so some contamination of its internal atmosphere and water system is expected. To protect space crews from contaminants in potable and hygiene water, the National Aeronautics and Space Administration (NASA) requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and review NASA's development of the exposure guidelines for specific chemicals. NASA selects water contaminants for which spacecraft water exposure guidelines (SWEGs) will be established; this involves identifying toxicity effects relevant to astronauts and calculating exposure concentrations on the basis of those end points. SWEGs are established for exposures of 1, 10, 100, and 1,000 days. This report is the second volume in the series, Spacecraft Water Exposure Guidelines for Selected Chemicals. SWEG reports for acetone, alkylamines, ammonia, barium, cadmium, caprolactam, formate, formaldehyde, manganese, total organic carbon, and zinc are included in this report. The committee concludes that the SWEGs developed for these chemicals are scientifically valid based on the data reviewed by NASA and are consistent with the NRC (2000) report, Methods for Developing Spacecraft Water Exposure Guidelines. SWEG reports for additional chemicals will be presented in a subsequent volume.

The International Space Station is a closed and complex environment, so some contamination of its internal atmosphere and water system is expected. To protect space crews from contaminants in potable and hygiene water, the National Aeronautics and Space Administration (NASA) requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and review NASA's development of the exposure guidelines for specific chemicals. NASA selects water contaminants for which spacecraft water exposure guidelines (SWEGs) will be established; this involves identifying toxicity effects relevant to astronauts and calculating exposure concentrations on the basis of those end points. SWEGs are established for exposures of 1, 10, 100, and 1,000 days. This report is the second volume in the series, Spacecraft Water Exposure Guidelines for Selected Chemicals. SWEG reports for acetone, alkylamines, ammonia, barium, cadmium, caprolactam, formate, formaldehyde, manganese, total organic carbon, and zinc are included in this report. The committee concludes that the SWEGs developed for these chemicals are scientifically valid based on the data reviewed by NASA and are consistent with the NRC (2000) report, Methods for Developing Spacecraft Water Exposure Guidelines. SWEG reports for additional chemicals will be presented in a subsequent volume.

NASA maintains an active interest in the environmental conditions associated with living and working in spacecraft and identifying hazards that might adversely affect the health and well-being of crew members. Despite major engineering advances in controlling the spacecraft environment, some water and air contamination is inevitable. Several hundred chemical species are likely to be found in the closed environment of the spacecraft, and as the frequency, complexity, and duration of human space flight increase, identifying and understanding significant health hazards will become more complicated and more critical for the success of the missions. To protect space crews from contaminants in potable and hygiene water, NASA requested that the National Research Council NRC provide guidance on how to develop water exposure guidelines and subsequently review NASA's development of the exposure guidelines for specific chemicals. This book presents spacecraft water exposure guidelines (SWEGs) for antimony, benzene, ethylene glycol, methanol, methyl ethyl ketone, and propylene glycol.

The National Aeronautics and Space Administration (NASA) maintains an active interest in the environmental conditions associated with living and working in spacecraft and identifying hazards that might adversely affect the health and well-being of crew members. Despite major engineering advances in controlling the spacecraft environment, some water and air contamination appears to be inevitable. Several hundred chemical species are likely to be found in the closed environment of the spacecraft, and as the frequency, complexity, and duration of human space flight increase, identifying and understanding significant health hazards will become more complicated and more critical for the success of the missions. NASA asked the National Research Council (NRC) Committee on Toxicology to develop guidelines, similar to those developed by the NRC in 1992 for airborne substances, for examining the likelihood of adverse effects from water contaminants on the health and performance of spacecraft crews. In this report, the Subcommittee on Spacecraft Water Exposure Guidelines (SWEGs) examines what is known about water contaminants in spacecraft, the adequacy of current risk assessment methods, and the toxicologic issues of greatest concern.

To protect space crews from contaminants in potable and hygiene water, NASA requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and subsequently review NASA's development of exposure guidelines for specific chemicals.

Progress in space safety lies in the acceptance of safety design and engineering as an integral part of the design and implementation process for new space systems. Safety must be seen as the principle design driver of utmost importance from the outset of the design process, which is only achieved through a culture change that moves all stakeholders toward front-end loaded safety concepts. This approach entails a common understanding and mastering of basic principles of safety design for space systems at all levels of the program organisation. Fully supported by the International Association for the Advancement of Space Safety (IAASS), written by the leading figures in the industry, with frontline experience from projects ranging from the Apollo missions, Skylab, the Space Shuttle and the International Space Station, this book provides a comprehensive reference for aerospace engineers in industry. It addresses each of the key elements that impact on space systems safety, including: the space environment (natural and induced); human physiology in space; human rating factors; emergency capabilities; launch propellants and oxidizer systems; life support systems; battery and fuel cell safety; nuclear power generators (NPG) safety; habitat activities; fire protection; safety-critical software development; collision avoidance systems design; operations and on-orbit maintenance. * The only comprehensive space systems safety reference, its must-have status within space agencies and suppliers, technical and aerospace libraries is practically guaranteed * Written by the leading figures in the industry from NASA, ESA, JAXA, (et cetera), with frontline experience from projects ranging from the Apollo missions, Skylab, the Space Shuttle, small and large satellite systems, and the International Space Station. * Superb quality information for engineers, programme managers, suppliers and aerospace technologists; fully supported by the IAASS (International Association for the Advancement of Space Safety)