Objectives
Crewmembers aboard spacecraft are continuously exposed to pollutants in the respirable air. These pollutants originate from materials offgassing, systems leaks, use of utility chemicals, payload leaks, human metabolism, and microbial metabolism. If pollutant concentrations reach high levels, the crew can experience disturbances in cardiac rhythms, eye and respiratory irritation, headache and disorientation, and be at higher risk for developing chronic disease (e.g. cancer). Furthermore, excessive air pollution can confound biomedical experiments conducted aboard the spacecraft. Therefore, the atmospheric environment on Mir was monitored to ensure that sources of pollution were controlled and the air revitalization system removed contaminants to safe levels. All samples were taken concurrently using four different air samplers (Grab Sample Container (GSC), Solid Sorbent Air Sampler (SSAS), formaldehyde badges and the Russian AK-1 air sampler).
Shuttle-Mir Missions Approach Results Earth Benefits Publications
James, J.T., T.F. Limero, S.W. Beck, L. Yang, M.P. Martin, M.L. Matney, P.A. Covington, J.F. Boyd. Toxicological Assessment of Air Contaminants During the Mir 19 Expedition. NASA/JSC/SD2. 1996.
James, J.T., T.F. Limero, S.W. Beck, L. Yang, M.P. Martin, M.L. Matney, P.A. Covington, J.F. Boyd, and D.A.W. Lind. Toxicological Investigation of Mir Air During NASA-2. Memorandum SD2-97-511, March, 1997.
Perry, J.L., J.T. James, H.E. Cole, T.F. Limero, S.W. Beck. Rationale and Methods for Archival Sampling and Analysis of Atmospheric Trace Chemical Contaminants onboard Mir and Recommendations for the International Space Station. NASA/MSFC White Paper, November, 1996.
Principal Investigators
Lana Mukhamedieva, M.D. Co-Investigators
Mir 17, STS-71/Mir-18, Mir 19, Mir 20
Preflight preparations of the GSC and SSAS were conducted at the NASA Johnson Space Center Toxicology Laboratory to ensure that each sampler was clean and would perform as expected. GSC samples were obtained by a crewmember removing the dust cover on the inlet, holding the canister away from the body, opening the valve for approximately 10 seconds, closing the valve, replacing the dust cap, and marking the time and place of the sample. Time-integrated air samples were taken using the SSAS by turning the selector knob to the desired tube and turning on the unit power switch. Approximately 24 hours later, the power switch was turned off. Formaldehyde badges were used to obtain a personal sample or area sample. The face cover was removed and the badge attached to the front of the crewmember's shirt or to a location near the command post with good air flow. At the end of the exposure period (approximately 12 hours for personal samples and 24 hours for area samples), the badge was removed and resealed by a crewmember. AK-1 samples were taken by removal of the end caps, pumping 500 ml of air through the tube (5 strokes with a 100 ml bellows pump), and resealing the tube.
In general, the atmospheric contaminants were greater than those found in the Space Shuttle, but the Mir contaminant levels still met U.S. acceptability standards except for mucosal irritants. In particular, formaldehyde, a mucosal irritant and carcinogen, was consistently found in concentrations slightly above the U.S. and Russian limits of 0.04 parts per million (ppm). Efforts are underway to improve our control of formaldehyde in spacecraft air by limiting sources such as hardware offgasing. Data from Mir-18 indicate that spatial variations in pollution levels are less than 20%. Temporal variations are generally limited unless a new source of air pollution, such as a new module opening or experiment startup, occurs. During Mir-18, a large spike of Freon 82 into the air was noted late in the expedition. Data from Mir 19 appear to be quite similar to data from Mir-18.
The air sampling devices developed and employed by NASA, in particular, the Solid Sorbent Air Sampler (SSAS), have practical applications for sampling air pollution in closed spaces from which ill health effects may result. For example, these devices can be used to sample air in submarines and commercial aircraft.
James, J.T., T.F. Limero, S.W. Beck, L. Yang, M.P. Martin, M.L. Matney, P.A. Covington, J.F. Boyd. Toxicological Assessment of Air Contaminants During the Mir-18 Expedition. NASA/JSC/SD2. 1995.
John T. James, Ph.D.
NASA/Johnson Space Center
Institute of Biomedical Problems
Valentina P. Savina, M.D.
Thomas F. Limero, Ph.D.
Steve W. Beck, M.S.
Lily Wang, Ph.D.
Millie P. Martin, Ph.D.
Marilyn L. Matney, Ph.D.
Phillip A. Covington, B.S.
John F. Boyd, M.S.
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Curator:
Julie Oliveaux
Responsible NASA Official: John Uri |
Page last updated: 07/16/1999
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