The Effects of Ambient Pressure on the Biological Response of Mice to Air Blast
Abstract
Mice were mounted on the endplate of the expansion chamber of an air-driven shock tube and exposed to sharp-rising overpressures of "long" duration while under initial pre-blast pressures ranging from 7 to 42 psi absolute. The shock pressures were recorded by piezoelectric pressure transducers. A total of 672 mice were exposed to pressure changes in two series of experiments. In one series, the animals were held under the initial pressure for one hour following the blast before being returned to the ambient pressure level of the laboratory. In the second series, the pressure on the mice was returned to ambient immediately following blast exposure. In both series, animal tolerance, expressed as LD sub 50 overpressures, increased linearly with increasing initial pressures. The LD sub50 -1- hour gauge pressures in the first series were 20.3, 31.0, 44.5, 55.4, and 91.8 psi for initial pressures of 7, 12, 18, 24, and 42 psia, respectively. The LD sub 50 pressures for the second series were below those of Series I for initial pressures above ambient and above them for initial pressures less than ambient. The values were 22.7, 37.9, 53.6, 61.3, and 68.4 psi for initial pressures of 7, 18, 30, 36, and 42 psia, respectively. These results indicated that pressurization of animals soon after blast exposure resulted in * a decrease in the mortality whereas decompression resulted in increased lethality. Practical and theoretical implications of the study were discussed. A promising but tentative procedure for scaling biological blast effects as a function of altitude was presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1965
- Accession Number
- ADA384507
Entities
People
- Edward G. Damon
Organizations
- University of New Mexico