Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants.

摘要

Several hundred contaminants are likely to be found in the closed environment of Space Station Freedom. Therefore, the National Aeronautics and Space Administration (NASA) is concerned with the potential toxicological hazards to humans that may be associated with entering and living within spacecraft for prolonged periods. The National Research Council's Committee on Toxicology was requested by NASA to recommend guidelines for developing spacecraft maximum allowable concentrations (SMACs) for space station contaminants. SMACs are defined as the maximum concentrations of airborne substances that will not cause adverse health effects, significant discomfort, or degradation in crew performance. Short-term SMACs (up to 24 hours) provide guidance for crew members to operate under emergency conditions. Such exposures may produce reversible mild health effects, but they do not interfere with or impair judgement. Long-term SMACs (up to 180 days) are intended to avoid adverse health effects, immediate and delayed. The multidisciplinary committee considered the issues of (1) translating animal data to predict toxicity for humans in space, (2) evaluating the toxicity of complex mixtures, and (3) modifying risk estimates to account for altered physiological changes caused by microgravity.