exposure. The cumulative effects of the exposures might lead to serious short-term and long-term health impairments (Richmond et al., 1981). For those without body armor, the effects of blast are more deadly, and the whole spectrum of blast injuries can be seen (Table 2.3). Apart from the injuries caused by blast overpressure (primary blast effects), they have an increased potential for penetrating injuries from shrapnel and other debris (secondary blast effects) and for acceleration and deceleration of the body and head (tertiary blast effects) (Figure 2.6). Moreover, although barriers and check points may be used to prevent vehicles and personnel carrying explosives from entering a facility, in urban areas it may not be possible to achieve the recommended standoff distances shown in Table 2.1, and even those distances may not be adequate to prevent BINT injuries.

A blast wave generated by an explosion starts with a single pulse of increased air pressure that lasts a few milliseconds. The negative pressure or suction of the blast wave follows the positive wave immediately (Owen-Smith, 1981). The duration of the blast wave—that is, the time that an object in the path of the shock wave is subjected to the pressure effects—depends on the type of explosive and the distance from the point of detonation (Clemedson, 1956). Table 2.1 summarizes the safety zones—that is, the standoff distances—for various types of bomb explosions.