24. Main factors of nuclear explosion. Characteristics, effects, and impact on human health.

Main factors of nuclear explosion are:

1) shock wave of a nuclear explosion;

2) light radiation of a nuclear explosion;

3) electromagnetic pulse;

4) the damaging effect of ionizing radiation;

5) the damaging effect of radiation factors on the radioactively contaminated land.

The destructive effects of electromagnetic pulse

An electromagnetic pulse is referred to the electromagnetic fields that accompany nuclear

explosions. The electromagnetic pulse is formed mainly as a result of the Compton’s effect.

The duration of the electromagnetic pulse of about 150-200 ms, the spectrum of its frequency is

rather wide - from units to hundreds of megahertz.

A special feature of the electromagnetic pulse, compared with other factors of nuclear explosion, is its ability to spread over hundreds of kilometers in the environment and by the means of various communications (networks of electricity and water, wired, etc.).

EMP induces high voltages, which disables the communication lines and power supply, wire and

wireless communication equipment. In addition, EMP can inflame the hardware and cause the defeat of people by electric shocks.

The destructive effect of radiation factors on the radioactively contaminated areas

Radioactive contamination in a nuclear explosion is particularly characteristic of explosions, based on the fission reaction and produced in the air near the ground, above ground, underground and in the water.

The fallout of soil particles (with surface and underground explosions) or water droplets (in

explosions in the water), containing the radioactive fission fragments of uranium or plutonium,

begins in a few minutes after a nuclear explosion, and continues until 1-1,5 hours.

In the course of movement of the clouds its ground track is formed, which is delimited on the zones of contamination. A trace of the radioactive fallout on the path of the cloud is generally elliptical in shape (with a uniform wind), whose axis is directed in the direction of the wind. The width of the radioactive trace is typically 5-10 times less than its length.

Considering the lethality of radioactive products of nuclear explosions on the person, it is advisable to allocate 2 periods: the period of formation of a trace, when the precipitation of radioactive particles falls out from the cloud of a nuclear explosion, and the period of the formed trace when the fallout has already fallen to the ground.

24. Medico-tactical characteristics of foci of nuclear damage

The center of nuclear destruction is a territory, where under the effects of a nuclear explosion occur destruction of various structures, radioactive contamination of areas and destruction of personnel. The structure of sanitary losses is primarily affected by the power of the explosion. With increasing power of the blast, the damage radius of the shock wave and the light emission increases to a much lesser extent than the radius of radiation injury, and therefore the structure of sanitary damages varies: the leading place is occupied by thermal burns and injuries.

Because the medical and tactical characteristics of foci of nuclear damage are determined by the

value, nature and structure of sanitary losses, the 3 types of nuclear foci are allocated:

1) center with predominant radiation injuries;

2) center with combined lesions;

3) center with predominant thermal injury.

Foci with predominantly radiation damage formed in explosions of nuclear or neutron weapons of small-and micro sizes. Minor damages of equipment and structures are accompanied with massive destruction of personnel by ionizing radiation. Combined damage is practically absent. A very high proportion of very severe radiation sickness (cerebral, intestinal, toxemic), is characterized by rapid and almost one-stage loss of the affected. Radioactive contamination in these outbreaks is virtually absent. Lesions caused by neutron ammunition, compared with the foci caused by nuclear ammunition of the same capacity, differ significantly by the increase in the range of ionizing radiation. Striking effect of ionizing radiation from the explosion of the neutron weapon with power of 1 kilotons is almost equivalent to the effect of ionizing radiation from the explosion of the nuclear weapon with power of 10 kilotons. Foci with combined lesions are formed mainly in explosions of nuclear weapons of medium caliber.

The most frequent and typical will be a combination of injuries from acute radiation, burns and

mechanical injuries simultaneously occurring at the time of a nuclear explosion.

Foci with combined lesions are subdivided into 2 groups:

1) with injuries mainly from radiation damage, when the proportion of "pure" form of radiation

sickness in the structure of sanitary losses is within 40-70%, and in the structure of combined lesions the leading is radiation damage; the predominant type of explosion is the air;

2) sanitary damages mainly from the mechanic-thermal injuries, when the percentage of burns in the structure of sanitary losses as high as 50-70%, and in the structure of the combined injuries the leading is trauma and burns; predominant type of explosions - above and below ground.

Typical for acute radiation injury disorders of the cardiovascular system are enhanced by

hemodynamic disorders caused by burns and injuries. At the weakening the body's defenses, which are caused by irradiation and non-radiation damage, not only the development of wound and burn infection are accelerated, but also increases the likelihood autoinfection.

Post radial anemia is particularly pronounced and prolonged, if it was preceded by a traumatic blood loss. Pathogenesis of various types of combined lesions depends not only on the number and types of components that make up the defeat, but also on their severity. In severe lesions of non-radiation and radiation effects of mild degree, the clinical picture, course and prognosis of lesions does not differ from the usual pattern of burns or mechanical injury.

If both types of exposure pronounced and cause the development of lesions of the average degree of severity, in such cases may occur more frequently traumatic and burn shock.

In general, the clinical picture of combined radiation injuries is characterized by:

1) a set of symptoms and syndromes that characterize not only the radiation pathology, but also

burns, closed and open fractures and mechanical damage, gunshot wounds, etc.,

2) absence of the latent period;

3) periodic prevalence of clinical signs of one of the components of the defeat,

4) syndrome of mutual aggravation of lesions;

5) more difficult, lengthy and complicated course.

In the clinical course of combined radiation injuries distinguish the following periods:

1) the acute period, or period of the primary reaction to irradiation and non-radiation effects;

2) the period of predominant symptomatology of non-radiation lesions;

3) the period of predominant symptomatology of radiation injury;

4) the recovery period.