Accession Number : ADA197726

Title :   Oxygen Toxicity During Five Simulated Eight-Hour EVA (Extravehicular Activity) Exposures to 100% Oxygen at 9.5 Psia,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX

Personal Author(s) : Webb, J. T. ; Olson, R. M. ; Krutz, R. W., Jr. ; Dixon, G. A. ; Barnicott, P. T.

Report Date : 1988

Pagination or Media Count : 8

Abstract : Human extravehicular mobility in space is crucial to satellite repair, space station construction, and a host of other activities. The current NASA pressure suit for Extravehicular Activity (EVA) maintains a differential pressure of 4.3 psia. Even with substantial prebreathing of 100% oxygen, the resultant decompression from 14.7 psia in the Shuttle or a space station allows significant potential for decompression sickness (DCS). If a pressure suit with adequate mobility could be developed which would maintain 14.7 psid (no decompression), the use of100% oxygen at that pressure would pose pulmonary oxygen toxicity problems if it were used for more than several hours during a single day. We conducted a study to determine if oxygen toxicity occurs in a proposed extravehicular activity (EVA) pressure suit environment. Twelve male subjects were exposed to 100% oxygen at 9.5 psia for 5 consecutive days, 8 h/day while performing moderate exercise. No decompression sickness or venous gas bubbles were detected. Pulmonary function tests, physical exams, blood analyses, arterial oxygen saturation monitoring, and x-rays showed no evidence of oxygen toxicity. These results suggest that a 100% oxygen, 9.5 psia pressure suit environment could avoid both decompression sickness and oxygen toxicity during EVAs of comparable duration and physical activity. Reprints. (kt)

Descriptors :   *DECOMPRESSION SICKNESS, *PRESSURE SUITS, ARTERIES, ARTIFICIAL SATELLITES, BLOOD ANALYSIS, BUBBLES, CONSTRUCTION, DAY, DECOMPRESSION, EXTRAVEHICULAR ACTIVITY, GASES, HUMANS, LUNG FUNCTION TESTS, MOBILITY, MONITORING, OXYGEN, PHYSICAL PROPERTIES, PULMONARY FUNCTION, REPAIR, REPRINTS, SATURATION, SPACE STATIONS, TIME, TOXICITY, VEINS.

Subject Categories : Stress Physiology
      Toxicology
      Protective Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE