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.
The primary objective of the "Toxicological Assessment of Airborne Volatile Organic Compounds" investigation was to periodically sample Mir air at various locations in the space station to estimate the effect of airborne pollutants on crew health. Secondary objectives were to assess the rate of pollutant mixing when the Shuttle hatch was open in the docked phase. Specific pollutants accumulate in Mir air and Shuttle air, which can be observed to redistribute or be diluted after opening the hatch between two spacecraft. Another objective was comparison of five samples taken simultaneously from different locations in the space station. Finally, samples were taken concurrently using three different air samplers (Grab Sample Container (GSC), Solid Sorbent Air Sampler (SSAS), and the Russian AK-1 air sampler) to compare the similarity of sampling methods.
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 Co-Investigators
Mir-21/NASA-2, Mir-22/NASA-3, Mir-23/NASA-4, Mir-24, Mir-25/NASA-6, Mir 26/NASA-7
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 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 contaminants levels still met U.S. acceptability standards except for mucosal irritants. In particular, formaldehyde, a mucosal irritant and carcinogen, was consistently found in concentrations above the U.S. and Russian limits of 0.04 parts per million (PPM). Data indicated that spatial variations in pollution levels were generally less than 25%. Temporal variations were generally limited unless a new source of air pollution, such as a new module opening or experiment startup, occurred. Results from canister samples and the SSAS were consistent; however, the Russian AK-1 sorbent system appeared to yield high results.
The air sampling devices developed and employed by NASA, in particular, the Solid Sorbent Air Sampler, 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
Thomas F. Limero, Ph.D.
Steve W. Beck, M.S.
Lilly Wang, Ph.D.
Millie P. Martin, Ph.D.
Marilyn L. Matney, Ph.D.
Phillip A. Covington, B.S.
John F. Boyd, M.S.Debra A. W. Lind, M.S.
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Curator:
Julie Oliveaux
Responsible NASA Official: John Uri |
Page last updated: 07/16/1999
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