Symptomatology during hypoxic exposure to flame-retardant chamber atmospheres.
Hypoxia was studied in 12 men during 63-h exposures to 17 and 13% O2, with the subjects serving as their own controls by repeating the measurements in 21% O2. All test atmospheres were contaminated with 0.9% CO2 to simulate the condition of living aboard submarines. The mean SaO2's were 97-98% in all conditions of 21% O2, 96% in 17% O2 (n.s.), and 92% in 13% O2 (P less than 0.05). The blood concentrations of 2,3-diphosphoglycerate were elevated in 13 and 17% O2 (P less than 0.05). Seventeen percent O2 did not cause significant symptoms of environmental stress; however, 13% O2 caused symptoms of acute mountain sickness in 5 of 12 men. In the last 7 h of exposure to 17% O2, reduction of the barometric pressure to 576 Torr reduced the ambient PO2 to 98 Torr (similar to the PO2 of 13% O2 at normobaric pressure). This induced symptoms of acute mountain sickness in 3 of 11 men. All symptomatology and physiologic changes were reversed during recovery in 21% O2. Monitoring devices indicated the presence of volatile organic contaminants at a mean concentration of 6.1 ppm in the chamber atmosphere. Combustion tests in the occupied chamber showed that flame propagation was retarded by lowering the O2 concentration from 21 to 13-17%. We conclude that men can live comfortably in a normobaric, flame-retardant atmosphere consisting of 17% O2-0.9% CO2-6.1 ppm volatile organic compounds-balance N2.
Knight
D R
DR
Naval Submarine Medical Research Laboratory, Naval Submarine Base, Groton, CT 06349-5900.
Cymerman
A
A
Devine
J A
JA
Burse
R L
RL
Fulco
C S
CS
Rock
P B
PB
Tappan
D V
DV
Messier
A A
AA
Carhart
H
H
D019794:2,3-Diphosphoglycerate; D000328:Adult; D000532:Altitude Sickness / Q000209:etiology; D001272:Atmosphere; D002245:Carbon Dioxide; D004163:Diphosphoglyceric Acids / Q000097:blood; D005390:Fires / Q000517:prevention & control; D005411:Flame Retardants / Q000009:adverse effects*; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000150:complications*; D008297:Male; D009584:Nitrogen; D010100:Oxygen; D012119:Respiration; D012449:Safety
D004163:Diphosphoglyceric Acids; D005411:Flame Retardants; D019794:2,3-Diphosphoglycerate; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen