A comparative study on viscera injuries caused by underwater blast wave and air blast wave

Objective To compare viscera injuries caused by underwater blast wave and air blast wave,and to provide some basis for their prevention and treatment.Methods The physical parameters of blast wave,including peak pressure value,positive duration and impulse,were measured during underwater and air explosions of 1 000 g TNT,respectively.A total of 26 dogs were used in animal experiments.20 of 26 dogs were used in underwater explosions of 1 000 g TNT,and another 6 dogs were used in air explosions with same quantity TNT.The survival rate and pathomorphological changes were observed 6 hours after injury.Results The peak pressure of underwater blast wave was markedly higher than that of air blast wave.Compared with air blast wave,the impulse of underwater blast wave was much greater,although the positive duration was some shorter.The results of bio-effects showed that underwater blast wave induced a high mortality (50% ) and large lethal boundary that was 12.5 m away from the explosive center.The lungs and abdominal viscera of the underwater explosion group dogs had a high incidence of injuries that were usually severe,whereas injuries caused by air blast wave were often mild.Some injuries occurred in a few animals,but no death was found in the air explosion experiments.Conclusions The peak pressure value and impulse of underwater blast wave,as well as the biological killing effects of underwater blast wave,were significantly greater than those of air blast wave caused by the same quantity TNT explosion.