Secondary blast injury is caused by what?

• A. Overpressure
• B. Debris or shrapnel
• C. Thermal burn
• D. Crushing force

Answer: (B)

Secondary blast injury occurs when debris from the explosion and surrounding environment is propelled at high speed, acting as projectiles that strike the body. Debris or shrapnel can penetrate skin and internal tissues, leading to penetrating wounds, organ damage, and internal bleeding. This contrasts with primary blast injury, which comes from the blast overpressure affecting air-filled organs; thermal burns from heat; and crushing or blunt force injuries from being struck or buried by debris. So the defining cause of secondary blast injury is debris or shrapnel.