Biochemical Comparisons of Two-Hour Exposures to Hydrogen-Oxygen, Helium-Oxygen and Nitrogen-Oxygen Atmospheres at 200 FSWG.

摘要

Biochemical and hematologic analyses were performed on urine blood samples collected from three civilian divers following exposure for 120 minutes to hydrogen-oxygen, helium-oxygen and nitrogen-oxygen breathing mixtures at simulated pressures of 200 feet of sea water (FSWG). Normoxic environments were maintained except when symptoms of hypoxia, which developed in the subjects breathing nitrogen-containing mixtures, were relieved by additional oxygen. Biological sampling was possible from selected dives during a series of two dives by each subject in each of the gaseous mixtures. An overall evaluation of the biochemical and hematologic signs of stress point to no greater or somewhat reduced stress in divers breathing hydrogen-oxygen compared to helium-oxygen mixtures. Greatest differences were noted during the earlier phases of recovery from the dives. Measurable biological changes as a result of nitrogen-oxygen diving were confounded by outward signs of distress such as nausea and increased frequency of decompression sickness. Biochemical data lend support to the general medical observation of biological safety of hydrogen-oxygen mixtures under the conditions tested. The potential advantage of decreased density and greater availability of hydrogen compared to helium indicate that further testing of hydrogen-containing atmospheres is warranted. (Author)