The Biodynamics of Air Blast

Abstract : After pointing out that accelerative and decelerative events are associated with the direct (pressure) and indirect (translational events including penetrating and nonpenetrating debris and whole body impact) effects of exposure to blast induced winds and pressure variations, some of the relevant biophysical parameters were selectively noted and discussed. These included the pressure time relationship; species differences; ambient pressure effects; the significance of positional (orientational) and geometric (situational) factors as they influence the wave form, the pressure "dose, " and the biologic response; and data bearing upon the etiology of blast injury. The consequences of pressure induced, violent implosion of the body wall and the significance of the associated variations in the internal gas and fluid pressures were described and emphasized as were alternating phases of "forced" hemorrhage and arterial air embolization; fibrin thrombi; coagulation anomalies; and renal, cardiac, and pulmonary sequelae. Tentative biomedical criteria consistent with recent interspecies scaling and modeling studies for assessing primary blast hazards were presented.