The Biological Effects of Repeated Blasts

Abstract : The results of investigations on the biological effects of repeated blasts were reviewed. In the present study, sheep and swine were subjected to multiple blasts at a rate of one per minute in a high-explosive-driven shocktube. Three 1% lethal doses (LD1) resulted in 100-percent mortality in 1 hour. Blast injuries to the organs in the neck (larynx, pharynx, and trachea) and the gastrointestinal tract occurred at blast overpressure levels lower than those necessary for lung hemorrhage for both single and multiple exposures. Curves estimating the LD1 for man as a function of incident overpressure and number of blasts were compiled. For a standing man the LD1 incident overpressure was 27 psi (186 kPa) for a single blast and 18 psi (124 kPa) for five blasts. The overpressures from one or five blasts required to inflict selected injuries in man were presented.