In the context of the active development of new technologies in the field of nuclear physics, one should always be on the alert. Indeed, on the account of our planet is not one sad experience of technological disasters and chemical accidents. Therefore, it will not be out of place to find out about the possible consequences of the accident and the procedure in the area of ​​chemical contamination. Let's consider this question in more detail.
Basic concepts
A typical technological accident is considered to be the penetration of hazardous chemicals into the outside world. This is due to damage to the collections of toxic elements and violation of the technological process with their participation, and ends with the infection of air, soil cover, water sources, flora and fauna and, of course, people.
The zone of chemical contamination means the territory (water area), within the boundaries of which the spread of toxic chemicals in such concentration and quantity that poses a threat to human life and health, as well as flora and fauna over a period of time.
Guided by the physical properties and aggregative state of AHOV, one can calculate the scale of infection. In this regard, primary and secondary clouds are distinguished. A cloud of poisonous air formed by instantly entering the atmosphere of the entire mass or part of a tank with HCW at the time of its damage is called primary. Secondary is a cloud with toxic fumes of spilled liquid.
Conditions of Poisoned Elements
In the zone of chemical contamination, HCWs move in one of 4 states: from droplet-liquid and vaporous to aerosol and gaseous.
The formation of the primary cloud can be promoted by hot VHF vapors released after the explosion or fire. Then they fall to the ground in a droplet form (after cooling and condensation), and the wind can carry away the condensate quite far from the accident site.
When HCW is released into the atmosphere in a droplet or solid form, their droplets (particles) settle on the territory. The area of ​​“coverage” determines the zone of dangerous chemical infection of the fertile layer of the earth.
Then, after evaporation, OHC particles rise and concentrate in the near-Earth part of the atmosphere in the form of a derivative cloud.
Under the influence of gravitational attraction of solid particles of toxic substances from an aerosol, the process of sedimentation in the form of dust occurs, and the mass formed after the explosion contains particles of different sizes (in the range of 0.5-300 ÎĽm), and the sedimentation rate increases from the particle size. If it is more than 50 (as often happens), then the cloud settles directly near the epicenter of the accident, if the average (30-50), then it can disperse in the range from one hundred to five hundred meters. The most dangerous for people are small particles up to 5 microns in size, because they are characterized by being in a suspended state and penetrating to a depth of up to a maximum mark of 10 kilometers.
It turns out that 2 territories fall into the zone of chemical infection: with direct exposure to AHOV and with the movement of the radioactive cloud. The most dangerous in an emergency situation at the KhOO sites where the toxic substance released into the atmosphere, forming a primary cloud.
The level of concentration of toxic substances
The closer the place of the “eruption” of GWS, the higher their density in the formed cloud. Then a gradual decrease in concentration occurs closer to the outskirts of the chemical infection zone. The limits of the latter are subject to variability, the reason for this is air masses with different directions. When air moves horizontally under the influence of wind, the infected cloud moves, affecting a larger area frontally and in depth. When the wind speeds above 6 m / s, the cloud dissipates quite quickly, and the concentration of toxic substances decreases. Moderate speed, on the contrary, contributes to the preservation of toxic mass above the surface layer of the atmosphere, which increases the scale of the recess.
Vertical atmospheric stability - types
The first state is called inversion. It is characterized by a lower temperature in the lower layer of air relative to the upper. This provides a high saturation of GW in the near-Earth part of the atmosphere and creates a “favorable climate” for horizontal expansion of the cloud.
In a state of inertia of the atmosphere (isothermal), when the temperature does not differ on both layers of air, the density of AHOV is not so pronounced.
If the atmosphere is characterized by instability, called convection, in the lower layer of air is “warmer” than in the upper one.
Atmospheric effects
Atmospheric precipitation plays a role in the process of precipitation of OXV: with their help, the liquid and solid components of chemical elements are washed out from the poisoning cloud. The rate of precipitation is maximum during rain and rain and is negligible when there is dry fog, mist or drizzle on the street.
Terrain Factor
The scale of the consequences is also affected by the nature of the territory, which is a zone of possible chemical contamination. If the terrain rises along the line of "flow" of the cloud, we can talk about a decrease in the depth of its diffusion. The top of the hill has a low degree of accumulation of AHOV. But in deep hollows with a fair cloud wind, its movement is active. The perpendicular orientation can provoke stagnation of the cloud.
Forest terrain restricts chemical cloud access. In populated areas, compared with open areas, VHF pairs are usually more condensed. Hazardous substances have the ability to enter enclosed spaces. The “Achilles heel” here is the building of train stations, public institutions and commercial premises. You can feel most safely in residential apartments.
Chemical Poison Properties
Their individual elements have a high penetrating property, which is fraught with poisoning of all spheres of the external environment.
Some HCBs can upset the ecological balance by infecting the biosphere for a long period (from a week to a month).
In the event of complete or partial destruction of chemical agents provoked by military operations or by a natural or man-made emergency, a number of different chemical agents can enter the atmosphere. In this case, several types of hazardous elements form a zone of chemical contamination. This allows you to determine the mass of the poisonous cloud, guided by the following parameters: quantity, physico-chemical properties and toxicity. The initial part of the zone “accumulates” all AHOV, and in the opposite, substances with a large amount and toxoid are concentrated. Do not forget that such a mixed poison cloud can explode and ignite due to the likely chemical reactions between the various components.
How to behave in a zone of chemical infection
If you heard a "chemical alarm" or found signs of the presence of toxic substances, you must adhere to the following rules:
- use personal protective equipment;
- take refuge immediately in the nearest shelter or in a sealed living room;
- at the entrance to the shelter leave PPE and outer clothing.
Moving through a poisoned area should be quick, but calm, so as not to raise dust. Also, do not lean on the walls of buildings and touch surrounding objects. On the way, you should bypass drops of liquid or scattered unknown substances in the form of a powder. The path to the shelter must be chosen without gullies, hollows, swamps and tunnels. If drops or traces of chemicals are found on the skin and garments, they should be treated with a swab soaked in liquid from an individual protection bag, if not, remove with paper, rags or a handkerchief.
Since the presence of people in chemically contaminated areas threatens radiation and radiation sickness, medical prophylaxis of ionizing lesions with anti-radiation drugs is carried out.