Effects of Partial Gravity on the Function and Particle Handling of the Human Lung
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Purpose of Review
The challenges presented to the lung by the space environment are the effects of prolonged absence of gravity, the challenges of decompression stress associated with spacewalking, and the changes in the deposition of inhaled particulate matter.
Although there are substantial changes in the function of the lung in partial gravity, the lung is largely unaffected by sustained exposure, returning rapidly to a normal state after return to 1G. Provided there is adequate denitrogenation prior to a spacewalk, avoiding the development of venous gas emboli, the lung copes well with the low-pressure environment of the spacesuit. Particulate deposition is reduced in partial gravity, but where that deposition occurs is likely in the more peripheral airspaces, with associated longer retention times, potentially raising the toxicological potential of toxic dusts.
Despite its delicate structure, the lung performs well in partial gravity, with the greatest threat likely arising from inhaled particulate matter (extra-terrestrial dusts).
KeywordsRespiratory Aerosol transport Deposition Gas exchange
Many of the studies were funded by NASA or the National Space Bimbedical Research Institute under various contracts and grants. GK Prisk is currently funded by NIH under R01 HL119263.
Compliance with Ethical Standards
Conflict of Interest
Dr. Prisk has nothing to disclose.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major Importance
- 6.West JB. Pulmonary gas flow and gas exchange. In: West JB, editor. Respiratory physiology: people and ideas. New York: Oxford Press; 1966. p. 140–96.Google Scholar
- 12.•• Prisk GK, Elliott AR, Guy HJB, Kosonen JM, West JB. Pulmonary gas exchange and its determinants during sustained microgravity on Spacelabs SLS-1 and SLS-2. J Appl Physiol. 1995;79:1290–8. This study shows that despite changes in the heterogeneity of both ventilation and perfusion in zero gravity, the important matching of these two remains comparable to that seen in 1G. CrossRefPubMedGoogle Scholar
- 14.Haase H, Baranov VM, Asyamolova NM, Polyakov VV, Avak yan YG, Dannenberg R, et al. First results of PO 2 examinations in the capillary blood of cosmonauts during a long-term flight in the space station “MIR”. 41st Congress of the International Astronautical Federation, Dresden, Germany. 1990:1–4.Google Scholar
- 37.•• Prisk G, Fine J, Cooper T, West J. Lung function is unchanged in the 1 G environment following 6-months exposure to microgravity. Eur J Appl Physiol. 2008;103(6):617–23. This study shows that long-duration exposure to zero gravity does not result in lasting deliterious consequence for the lung. CrossRefPubMedGoogle Scholar
- 39.Permutt S. Pulmonary circulation and the distribution of blood and gas in the lungs. Physiology in the space environment. Washington: NAS NRC 1485B; 1967. p. 38–56.Google Scholar
- 47.Waligora JM, Horrigan D, Jr., Conkin J, Hadley AT, III. Verification of an altitude decompression sickness prevention protocol for shuttle operations utilizing a 10.2-psi pressure stage. NASA Technical Memorandum 58259. Houston: NASA; 1984. p. 1–44.Google Scholar
- 48.Conkin J, Klein JS, Acock KE. Description of 103 cases of hypobaric decompression sickness from NASA-sponsored research (1982-1999). Houston, Texas: Johnson Space Center; 2003. Report No.: NASA Technical Publication 2003–212052.Google Scholar
- 49.Cotes JE. Assessment and application in medicine. Lung Funct. 1993;5:251–62.Google Scholar
- 51.Graf JC. Lunar soil size catalog. 1993. Report No.: NASA-RP-1265.Google Scholar
- 62.•• Darquenne C, Prisk G. Deposition of inhaled particles in the human lung is more peripheral in lunar than in normal gravity. Eur J Appl Physiol. 2008;103(6):687–95. This study shows that while aerosol deposition is reduced in lunar gravity, those particles that re-deposited do so in more peripheral locations in the airways, likely increasing their residence time. CrossRefPubMedGoogle Scholar