People everywhere are surrounded by many dangers. One of the many threats we deal with on a daily basis is electricity. The outcome of an electric shock to a person can be different - from minor reactions of the body to extremely severe injuries that can lead to death.
The severity of damage depends not only on the indicators of electricity voltage. There are many different factors that affect the outcome of an electric shock. Let's analyze them in more detail.
Type and frequency
AC and DC have different effects on the body. Let's take a closer look.
Alternating current is more dangerous than direct current, but its danger begins to decrease after reaching a frequency of 1000 Hz. This is an amazing fact. Thus, alternating currents with frequencies of 100 Hz and 1000 Hz are the same danger. A permanent one becomes a threat only when itvoltage reaches 500 volts or more. Explain.
Under normal conditions, the smallest value of direct current that can cause a reaction in the body is 5 mA, for alternating current - 1 mA.
Which values are dangerous? A threat to life is an alternating current of 15 mA and a constant current of 60 mA. When exposed to such frequencies on the human body, paralysis often occurs, in which it becomes impossible to independently break away from the electrical wire. According to studies, shock with a frequency of 100 to 250 mA can be fatal.
The level of electric shock can be determined by the response of the body. How? If you touch objects that are energized with direct current, the person will be thrown sharply to the side. This situation often leads to fractures and bruises. From the impact of alternating current, the muscles of the parts of the body that touch the wire begin to contract convulsively. The victim cannot release the source on his own.
Voltage
Voltage is a well-known factor influencing the outcome of electric shock. Studies show that a safe value for a person that can affect his body without a threat to life and he alth does not exceed 30 volts. However, serious consequences can also occur at voltages of less than 15 volts. Cases are also known that when a current with a voltage of a thousand volts was struck, death did not occur. It follows from this that safe limits of electric voltage are impossible withset accuracy. Other factors also influence the outcome. But we can say with confidence: the higher the voltage, the greater the danger it poses to life.
Types of lesions
The impact of the current is divided into the following types:
- Mechanical. Causes rupture and separation of the walls of blood vessels, lungs, muscle tissue.
- Thermal. Causes burns to parts of the body, an increase in the temperature of blood vessels, heart, brain and other organs.
- Biological. With it, irritation occurs, followed by excitation of muscle and nerve tissues. As a result of their involuntary contraction, a complete stop of the heart and breathing can occur.
- Electrolytic. Able to decompose organic fluids and blood, causing changes in their characteristics.
Share these types of lesions as a result of exposure to current:
- Local electrical injuries - large local damage to body tissues caused by the action of an electric current or an electric arc.
- Electric burn. It is most often caused by short circuits in appliances or when switches are turned on, which are under high load.
- Electrical signs are oval or round spots of a pale yellow or gray hue, caused by the chemical or mixed action of current.
- Metallization of the skin is the result of an electric arc, when the smallest particles of molten metal penetrate the human skin.
- Electroophthalmia - occurs inperson as a result of exposure to an electric arc that produces strong ultraviolet radiation. After 2-6 hours, the victim develops inflammation of the outer membranes of the eyes.
- Mechanical damage. Uncontrolled muscle contractions cause ruptures of the skin, blood vessels, nerve tissues, dislocations of joints, and bone fractures.
- Electric shock - excitation of tissues, resulting in a convulsive reaction. A person becomes inattentive, distracted, his memory weakens.
- Electric shock is a severe neuro-reflex reaction of the body resulting from a powerful electric current. As a result, respiratory distress, metabolic disorders, dysfunction of the circulatory system occur.
In addition, depending on the severity of a person's condition, electric shock is divided into four degrees:
I - spasmodic muscle contraction, the person is conscious.
II - involuntary muscle contractions, the victim loses consciousness, cardiac and respiratory activity is preserved.
III - a person loses consciousness, the work of the heart and respiratory system is disturbed.
IV - respiratory and circulatory arrest occurs, no signs of life.
Current path
When exposed to electricity on vulnerable parts of the body, a severe injury can occur even with a current strength of several milliamps. Such places are those zones through which the discharge can pass to the brain, heart and lungs.
Therefore, the most dangerous places for electric current are consideredback, temple, palm, front of legs, neck. These zones also have high electrical conductivity.
Duration
The period the body is exposed to is an important factor influencing the outcome of an electric shock. Over time, the discharge has an increasingly harmful effect on the cells: every minute the number of affected increases. The magnitude of the current increases over time, and the resistance of the body falls, as the body heats up. Prolonged exposure to even a low current frequency can be fatal.
It is impossible to accurately name the maximum time of exposure to electricity on the body, which will not lead to serious consequences. It happens that even fractions of a second drastically change a person's life. Cases are also known that a longer amount of time (several seconds) the flow of current through the body did not lead to death or serious consequences.
Human body resistance, mood
Information will not be complete without considering the following factor in the outcome of electric shock. The resistance of the human body is constantly changing, and its value fluctuates widely. Its value is also influenced by the humidity of the skin, the environment, the place of contact, clothing and even the mood of a person.
People who expect an electric shock have been proven to take the shock less severely than those who experience it unexpectedly. Man, knowing that heis in danger, works in a state of increased attention and knows what to expect. The most severe consequences of electric shock endure those who did not expect that this could happen.
Individual features of the organism
It is noteworthy that women are much more difficult to tolerate electric shock than men. This is explained by the fact that they have more delicate skin and a thin stratum corneum, through which current easily passes. Age also plays a role. Most often, electric current affects children and the elderly.
The he alth of people affects the outcome of electric shock. As practice shows, people with a strong physical form tolerate an electric shock much better, which cannot be said about those who have he alth problems.
The body of those suffering from serious diseases is highly susceptible to the effects of electricity. At jobs associated with the maintenance of power plants, there is a whole list that indicates a number of diseases that prohibit admission to work. These diseases include tuberculosis, heart disease, mental disorders.
The outcome of electric shock also aggravates the presence of alcohol in the blood.
First aid
An electrical shock victim needs medical attention before an ambulance arrives or before you take them to a medical facility yourself.
First of all, it is necessary to free a person from the effects of electricity. For thisthere are certain safety precautions that must be observed.
If the victim is conscious, he should be laid on a soft surface, not allowed to move, and monitor the pulse and breathing. A person who has lost consciousness must be provided with access to a stream of fresh air, after laying him in a horizontal position, bring a cotton swab moistened with ammonia to his nose, periodically spray his face with cold water, and remove tight clothing.
If the victim does not have a pulse, he does not breathe, there is no heartbeat, it is urgent to give him artificial respiration and heart massage. All this is desirable to carry out within five minutes after the incident. It would be a big mistake to consider a person dead and not help him. Electrocution often results in near-death experiences that require immediate action to save a life.
In addition to the listed factors that determine the outcome of an electric shock, there are many others. In order to somehow protect yourself, you need to know about it. It should also be borne in mind that only one indicator cannot affect the severity of damage from electric shock. Factors affecting the outcome of a strike are taken into account in the aggregate. Electricity is life-threatening!
