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Ministry of Education of the Russian Federation

Kazan National Technical University. A.N. Tupolev

Department of General Chemistry and Ecology

abstract

By discipline: Toxicology

Topic: Ways of penetration of poisons into the body

Kazan, 2013

General concepts of poisons and poisonings

Poisoning is a disease caused by the introduction of toxic substances into the body.

Poison is a relative concept, since various toxic substances, depending on their properties and quantity, can be not only useful, but also necessary for the body. However, the same substances, taken in large quantities, can cause health problems and even death. So, table salt, introduced in normal quantities, is an essential food product, but 60 - 70 g of it cause poisoning phenomena, and 300 - 500 g - death; even ordinary water, taken in large quantities, can cause poisoning and death. When distilled water is ingested, poisoning phenomena are observed, its introduction into the blood can result in death. It is generally accepted that poisons are those substances that, when introduced into the body in minimal quantities, cause severe disorders or death. In some cases it is difficult to draw a sharp line between poison and medicine.

The study of poisoning deals with the science of poisons - toxicology. It studies the physical and chemical properties of poisons, harmful effects, routes of penetration, the transformation of poisons in the body, means of preventing and treating poisoning, and the possibility of using the action of poisons in medicine and industry.

A number of conditions are necessary for the onset of poisoning. One of them is the penetration of a toxic substance into the blood, and through it into the cells of organs and tissues. This disrupts the course of normal processes, changes or destroys the structure of cells and leads to their death. For poisoning to occur, a certain amount of poison must be injected. Symptoms, severity, duration of the course and outcome of poisoning depend on the amount of poison administered.

For all potent and poisonous substances, the State Pharmacopoeia establishes doses that guide doctors in their practice. The dose can be therapeutic, toxic and lethal. A therapeutic dose is a certain minimum amount of a potent or poisonous substance that is used for therapeutic purposes; toxic - causes a health disorder, i.e. poisoning phenomena; lethal dose is the minimum amount of poison per kilogram of body weight that can cause death.

At the same dose, the concentration of the poison in the body is not the same: the greater the body weight, the lower the concentration of the poison and vice versa. The same dose affects people differently. The introduction of a certain amount of poison to a large, physically strong person may pass without any complications, but the dose taken by a thin and weak subject may be toxic. With an increase in the dose, the toxic effect increases disproportionately: an increase in the dose by 2 times can increase the toxicity by 15 or more times.

The Pharmacopoeia establishes different doses for adults and children. Children are highly sensitive to poisons, in particular to drugs. Increased sensitivity to poisons is observed in the elderly, as well as in women, especially during menstruation or pregnancy. The course and outcome of poisoning worsens the presence of various diseases of the internal organs in the victim, especially the liver, kidneys, and heart. Thus, the development, course and outcome of poisoning depend not only on the dose of the poison, but also on the state of the organism.

One of the necessary conditions for the development of chronic poisoning is the so-called cumulation of poison, that is, its gradual accumulation in certain organs and tissues. This can take place in cases where conditions are created for the constant intake of small doses of poison into the body. In this case, an important role is played by a violation of the processes of excretion of poison from the body, since the accumulation process is mainly expressed in the ratio between the intake of a toxic substance and its removal from the body.

A necessary condition for the development of poisoning is the physical state of the poison, which is of great importance in the process of its absorption and assimilation. Insoluble in water, poisonous substances in the gastrointestinal tract, as a rule, are harmless to the body: they are not absorbed, or are absorbed into the blood in small quantities. Soluble toxic substances are quickly absorbed and therefore act much faster, for example, barium chloride, which is easily soluble in water, is very toxic, and barium sulfate, which is insoluble in water and body fluids, is harmless and is widely used in x-ray diagnostic practice. A strong curare poison introduced through the mouth does not cause poisoning, since it is absorbed very slowly, and is excreted from the body much faster, but the same amount of poison introduced into the blood leads to death. Of great importance is the concentration of the poison. So, highly diluted hydrochloric acid is almost harmless to the body, and concentrated is the strongest poison. Gaseous poisons act especially quickly; getting through the lungs into the blood, they immediately spread throughout the body, showing their inherent properties.

One of the conditions for the development of poisoning is the quality of the poison, that is, its chemical purity. Often a poisonous substance is introduced into the body with various impurities that can enhance or weaken the effect of the poison, and sometimes even neutralize it.

Ways of entry of poisons into the body

The entry of poisons into the human body can occur through the respiratory system, the digestive tract and the skin. And the main ones are the respiratory tract. Poisons penetrating through them have a stronger effect on the body than poisons penetrating through the intestines, since in the first case they directly enter the blood, and in the second they pass through the liver, which detains and partially neutralizes them.

In investigative and forensic practice, there are cases of the introduction of poison intravenously, subcutaneously, as well as into the vagina and rectum. In the stomach, the poison is absorbed relatively slowly due to the fact that its inner wall is covered with a mucous layer, which prevents the poison from quickly penetrating into the blood. But some poisons, such as hydrocyanic acid compounds, are absorbed very quickly. Poisons, being in the stomach, often cause irritation of its walls, as a result of which vomiting occurs and part or all of the toxic substance is excreted. With a full stomach, the poison is absorbed more slowly than with an empty one. The most complete absorption occurs in the small intestine.

Poisoning occurs through the lungs with poisonous gases and vapors, such as carbon monoxide, hydrogen sulfide, hydrocyanic acid vapors. At appropriate concentrations, poisoning occurs very quickly due to the ease of passage of the poison through the alveoli of the lungs and into the blood.

Some poisons, such as mercury preparations, easily penetrate the body through the skin, and the integrity of the surface layer of the skin - the epidermis - matters; wounds, abrasions and, in general, places devoid of the epidermis are more vulnerable to the penetration of poisons into the body.

In the rectum and in the vagina, absorption occurs quite quickly. Poisoning through the vagina can occur when a poisonous substance is used for the purpose of criminal abortion, as well as medical errors.

Entry of substances through the lungs

The huge surface of the pulmonary alveoli (about 80-90 m2) provides intensive absorption and a quick effect of the action of toxic vapors and gases present in the inhaled air. In this case, first of all, the lungs become the "entrance gate" for those of them that are well soluble in fats. Diffusing through the alveolar-capillary membrane with a thickness of about 0.8 microns, which separates the air from the bloodstream, the molecules of poisons penetrate the pulmonary circulation in the shortest way and then, bypassing the liver, through the heart reach the blood vessels of the systemic circulation.

The possibility of a substance entering through the lungs is determined primarily by its state of aggregation (steam, gas, aerosol). This route of penetration of industrial poisons into the body is the main and most dangerous, since the surface of the pulmonary alveoli occupies a significant area (100-120 m2), and the blood flow in the lungs is sufficient intense.

The rate of absorption of chemicals into the blood depends on their state of aggregation, solubility in water and biological media, partial pressure in the alveolar air, the value of pulmonary ventilation, blood flow in the lungs, the state of the lung tissue (the presence of inflammatory foci, transudates, exudates), the nature of the chemical interaction with biosubstrates of the respiratory systems.

The entry of volatile chemicals (gases and vapors) into the blood is subject to certain patterns. Non-reacting and reacting gases and vaporous substances are absorbed differently. Absorption of non-reacting gases and vapors (hydrocarbons of the fatty and aromatic series and their derivatives) is carried out in the lungs according to the principle of simple diffusion in the direction of decreasing the concentration gradient.

For non-reacting gases (vapours), the distribution coefficient is a constant value. By its value, one can judge the danger of severe poisoning Gasoline vapors (K - 2.1), for example, at high concentrations can cause instantaneous acute and even fatal poisoning. Acetone vapors, which have a high distribution coefficient (K = 400), cannot cause acute, let alone fatal poisoning, since acetone, unlike gasoline, saturates the blood more slowly.

When reacting gases are inhaled, saturation of body tissues does not occur due to their rapid chemical transformation. The faster the processes of biotransformation of poisons take place, the less they accumulate in the form of their products. Sorption of reacting gases and vapors occurs at a constant rate. The percentage of sorbed substance is directly dependent on the volume of respiration. As a result, the danger of acute poisoning is the greater, the longer a person stays in a polluted atmosphere, the development of intoxication can be facilitated by physical work performed in a heating microclimate.

The point of application of the action of reacting gases and vapors can be different. Some of them (hydrogen chloride, ammonia, sulfur oxide (IV)), which are highly soluble in water, are sorbed mainly in the upper respiratory tract; material (chlorine, nitric oxide (IV)), which are less soluble in water, penetrate into the alveoli and are sorbed into mostly there.

Penetration of poisons through the skin

The skin is one of the possible routes of entry of poisons into the body. Only lipid-soluble substances penetrate the epidermis. Water-soluble substances penetrate the skin only in small amounts. The penetration of water-soluble substances into the body is prevented by the fatty layer formed on the surface of the skin as a result of the secretory activity of the sebaceous glands. Nicotine, tetraethyl lead, chlorine derivatives of hydrocarbons, chlorine-containing pesticides, aromatic amines, fatty hydrocarbons (from C 6 to C 10), finely ground salts of thallium, mercury and other metals easily penetrate the skin. With mechanical damage to the skin, burns, the penetration of toxic substances through the skin increases.

The mechanism of absorption of chemicals through the skin is complex. Perhaps their direct (transepidermal) penetration through the epidermis, hair follicles and sebaceous glands, sweat gland ducts. Different areas of the skin have a different ability to absorb industrial poisons; skin on the medial surface of the thighs and arms, in the groin, genitals, chest and abdomen is more suitable for the penetration of toxic agents.

At the first stage, the toxic agent passes through the epidermis - a lipoprotein barrier that passes only for gases and fat-soluble organic substances. At the second stage, the substance enters the blood from the dermis. This barrier is available for compounds that are well or partially soluble in water (blood). The danger of skin-resorptive action increases significantly if the indicated physico-chemical properties of the poison are combined with high toxicity.

Industrial poisons that can cause intoxication if penetrated through the skin include aromatic amino and nitro compounds, organophosphorus insecticides, chlorinated hydrocarbons, that is, compounds that do not dissociate into ions (not electrolytes). Electrolytes do not penetrate the skin, they are retained, as a rule, in the horny or shiny layer of the epidermis. The exception is heavy metals such as lead, tin, copper, arsenic, bismuth, mercury, antimony and their salts. Combining with fatty acids and sebum on the surface or inside the stratum corneum of the epidermis, they form salts that are able to overcome the epidermal barrier.

Not only liquid substances that pollute it penetrate through the skin, but also volatile gas and vapor non-electrolytes, the skin is an inert membrane through which they penetrate by diffusion.

The absorption of toxic substances from the digestive tract in most cases is selective, since its different departments have their own structure, innervation, chemical environment and enzymatic glass.

Some toxic substances (all fat-soluble compounds, phenols, some salts, especially cyanides) are already absorbed in the oral cavity. At the same time, the toxicity of substances increases due to the fact that they are not exposed to the action of gastric juice and, bypassing the liver, are not neutralized in it.

All fat-soluble substances and non-ionized molecules of organic substances are absorbed from the stomach by simple diffusion. Through the pores of the cell membrane of the gastric epithelium, penetration of substances by filtration is possible. Many poisons, including lead compounds, dissolve better in gastric contents than in water, and therefore are better absorbed. Some chemicals, once in the stomach, completely lose their current toxicity or it is significantly reduced through inactivation by gastric contents.

The nature and rate of absorption are significantly affected by the degree of filling of the stomach, solubility in gastric contents and its pH. Substances taken on an empty stomach are absorbed, as a rule, more intensively.

Absorption through the digestive tract

poison poisoning epidermis blood

With poisoned food, water, as well as in a "pure" form, toxic substances are absorbed into the blood through the mucous membranes of the oral cavity, stomach and intestines. Most of them are absorbed into the epithelial cells of the digestive tract and further into the blood by a simple diffusion mechanism. At the same time, the leading factor in the penetration of poisons into the internal environment of the body is their solubility in lipids (fats), more precisely, the nature of the distribution between the lipid and aqueous phases at the site of absorption. The degree of dissociation of poisons also plays a significant role.

As for fat-insoluble foreign substances, many of them penetrate the cell membranes of the mucous membranes of the stomach and intestines through the pores or spaces between the membranes. Although the pore area is only about 0.2% of the entire membrane surface, it nevertheless ensures the absorption of many water-soluble and hydrophilic substances. By the blood flow from the gastrointestinal tract, toxic substances are delivered to the liver, an organ that performs a barrier function in relation to the vast majority of foreign compounds.

The absorption of toxic substances from the digestive tract occurs mainly in the small intestine. Fat-soluble substances are well absorbed by diffusion. Lipophilic compounds quickly penetrate the intestinal wall, but are relatively slowly absorbed into the blood. For rapid absorption, the substance has good solubility in lipids and water. Solubility in water promotes the absorption of poison from the intestinal wall into the blood. The absorption rate of chemicals depends on the degree of ionization of the molecule. Strong acids and alkalis are absorbed slowly due to the formation of complexes with intestinal mucus. Substances similar in structure to natural compounds are absorbed through the mucous membrane by active transport, which ensures the supply of nutrients.

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The main tasks of toxicological chemistry. The role of chemical-toxicological analysis in the work of centers for the treatment of poisoning. Characteristics of the duties of an expert chemist. Influence of physical and chemical properties of poisons on their distribution and accumulation in the body.

Vapors, gases, liquids, aerosols, chemical compounds, mixtures in contact with the human body can cause changes in health or disease. Exposure to harmful substances on a person can be accompanied by poisoning and injury.

Toxic substances enter the human body through the respiratory tract (inhalation), the gastrointestinal tract and the skin. The degree of poisoning depends on their state of aggregation (gaseous and vaporous substances, liquid and solid aerosols) and on the nature of the technological process (heating of the substance, grinding, etc.).

The overwhelming majority of occupational poisonings are associated with inhalation penetration of harmful substances into the body, which is the most dangerous, since the large suction surface of the pulmonary alveoli, intensively washed with blood, causes a very rapid and almost unhindered penetration of poisons to the most important vital centers.

The intake of toxic substances through the gastrointestinal tract under production conditions is quite rare. This happens due to violation of personal hygiene rules, partial ingestion of vapors and dust penetrating through the respiratory tract, and non-compliance with safety regulations when working in chemical laboratories. It should be noted that in this case, the poison enters through the portal vein system into the liver, where it is converted into less toxic compounds.

Substances that are highly soluble in fats and lipoids can enter the bloodstream through intact skin. Severe poisoning is caused by substances with increased toxicity, low volatility, and rapid solubility in the blood. Such substances include, for example, nitro- and amino products of aromatic hydrocarbons, tetraethyl lead, methyl alcohol, etc.

Toxic substances in the body are distributed unevenly, and some of them are capable of accumulating in certain tissues. Here, electrolytes can be especially distinguished, many of which very quickly disappear from the blood and concentrate in individual organs. Lead accumulates mainly in the bones, manganese - in the liver, mercury - in the kidneys and large intestine. Naturally, the peculiarity of the distribution of poisons can to some extent be reflected in their further fate in the body.

Entering the circle of complex and diverse life processes, toxic substances undergo various transformations in the course of oxidation, reduction, and hydrolytic cleavage reactions. The general direction of these transformations is most often characterized by the formation of less toxic compounds, although in some cases more toxic products can also be obtained (for example, formaldehyde during the oxidation of methyl alcohol).

The excretion of toxic substances from the body often occurs in the same way as the intake. Unreacting vapors and gases are partially or completely removed through the lungs. A significant amount of poisons and their transformation products are excreted through the kidneys. A certain role for the release of poisons from the body is played by the skin, and this process is mainly performed by the sebaceous and sweat glands.

The toxic effect of certain harmful substances can manifest itself in the form of secondary lesions, for example, colitis with arsenic and mercury poisoning, stomatitis with lead and mercury poisoning, etc.

The danger of harmful substances to humans is largely determined by their chemical structure and physicochemical properties. Of no small importance in relation to toxic effects is the dispersion of a chemical substance penetrating the body, and the higher the dispersion, the more toxic the substance.

According to the nature of the impact on the human body, chemicals are divided into:

General toxic chemicals (hydrocarbons, alcohols, aniline, hydrogen sulfide, hydrocyanic acid and its salts, mercury salts, chlorinated hydrocarbons, carbon monoxide) that cause nervous system disorders, muscle cramps, disrupt the structure of enzymes, affect blood-forming organs, interact with hemoglobin .

· Irritants (chlorine, ammonia, sulfur dioxide, acid mists, nitrogen oxides, etc.) affect the mucous membranes, upper and deep respiratory tract.

Sensitizing substances (organic azo dyes, dimethylaminoazobenzene and other antibiotics) increase the body's sensitivity to chemicals, and in production conditions lead to allergic diseases

· Carcinogenic substances (benz (a) pyrene, asbestos, nitroazo compounds, aromatic amines, etc.) cause the development of all cancers. This process may be years or even decades distant from the moment of exposure to the substance.

Mutagenic substances (ethyleneamine, ethylene oxide, chlorinated hydrocarbons, lead and mercury compounds, etc.) affect non-sex (somatic) cells that are part of all human organs and tissues, as well as germ cells (gametes). The impact of mutagenic substances on somatic cells causes changes in the genotype of a person in contact with these substances. They are found in the remote period of life and manifest themselves in premature aging, an increase in the general morbidity, and malignant neoplasms. When exposed to germ cells, the mutagenic effect affects the next generation, sometimes in a very long time.

· Chemicals that affect human reproductive function (boric acid, ammonia, many chemicals in large quantities), cause congenital malformations and deviations from the normal structure in the offspring, affect the development of the fetus in the uterus, postpartum development and offspring health.

The last three types of harmful substances (mutagenic, carcinogenic, and affecting reproductive ability) are characterized by long-term consequences of their influence on the body. Their action is not manifested during the period of exposure and not immediately after its end. And in remote periods, years and even decades later.

The maximum allowable concentration (MAC) of harmful substances is the maximum concentration of a harmful substance that does not affect human health and its offspring, as well as ecosystem components and the natural community as a whole, over a certain time of exposure.

Harmful substances according to the degree of impact on the human body are divided into four hazard classes:

-(> first class - extremely dangerous with MPC< 0,1 МГ/МЗ (свинец, ртуть - 0,001 мг/м з);

-(> second class - highly hazardous with MPC = 0.1 ... 1 mg / m3 (chlorine - 0.1 mg / m3; sulfuric acid - 1 mg / m3);

- (> third class - moderately dangerous with MPC = 1.1 ... 1 O mg / m s (methyl alcohol - 5 mg / m s; dichloroethane - 10 mg / m s));

- (> fourth class - low-hazard with MPC> 1 O mg / m s (for example, ammonia - 20 mg / m s; acetone - 200 mg / m s; gasoline, kerosene - 300 mg / m s; ethyl alcohol 1000 mg / m H).

By the nature of the impact on the human body, harmful substances can be divided into groups: irritating (chlorine, ammonia, hydrogen chloride, etc.); suffocating (carbon monoxide, hydrogen sulfide, etc.); narcotic (nitrogen under pressure, acetylene, acetone, carbon tetrachloride, etc.); somatic, causing disturbances in the body's activity (lead, benzene, methyl alcohol, arsenic).

Measures for the prevention of occupational poisoning include hygienic rationalization of the technological process, its mechanization and sealing.

An effective remedy is to replace poisonous substances with harmless or less toxic ones. Of great importance in the improvement of working conditions is hygienic regulation, which limits the content of harmful substances by establishing MPC in the air of the working area and on the skin. For this purpose, hygienic standardization of raw materials and products is carried out, which provides for limiting the content of toxic impurities in industrial raw materials and finished products, taking into account their harmfulness and danger.

A large role in the prevention of occupational intoxication belongs to the mechanization of the production process, which makes it possible to carry it out in closed equipment and minimizes the need for the worker to come into contact with toxic substances (mechanical loading and unloading of fertilizers, washing and detergents). Similar problems are solved when sealing production equipment and premises that emit toxic gases, vapors and dust. A reliable means of combating air pollution is the creation of a certain vacuum that prevents the release of toxic substances through existing leaks.

Sanitary and technical measures include ventilation of working premises. Operations with especially toxic substances should be carried out in special fume hoods with powerful suction or in closed equipment.

Ways of penetration of harmful substances.

1. Harmful substances can enter the body through the respiratory system, gastrointestinal tract, skin. The most dangerous way for harmful substances to enter the body is

1. through the respiratory system (inhalation route), because harmful substances are immediately absorbed by the respiratory tract.
2. The penetration of harmful substances through the digestive tract when eating, smoking, drinking water is less dangerous, because. harmful substances partially pass through the intestines without lingering, are partially neutralized in the liver and excreted.
3. The entry of toxic substances into the body through the skin plays a significant role, although intact skin is impervious to many toxic substances. Aromatic and chlorinated hydrocarbons penetrate the skin well - benzene, xylene, toluene, dichloroethane, carbon tetrachloride, some organic metal compounds: tetraethyl lead, ethyl mercuric chloride, cyanides, etc.

4.Injectable

Absorption through the respiratory tract- the main route of entry of harmful substances into the human body at work. Inhalation poisoning is characterized by the fastest entry of poison into the blood.

2 Measures to prevent infectious diseases.

In order to make the human body immune to infectious diseases, health authorities are implementing measures to creation and strengthening of immunity in the population.

Measures in relation to a receptive collective. Of great importance in the prevention of infectious diseases, especially in children's groups, is mass immunization - prophylactic vaccination, the introduction of specific sera or gamma globulins (see the table "Vaccination Calendar").

In the case when the causative agents of the disease are unknown and there are no appropriate vaccines, it is used emergency prophylaxis - use of antibiotics and other antimicrobial means to fight the disease. Vaccination can be carried out by intradermal administration, subcutaneous administration, skin and aerosol methods.

Proper nutrition and a healthy lifestyle- one of the main measures for the prevention of infectious and other types of diseases.

For some infectious diseases, such as AIDS and hepatitis B, prevention is the key to control. These diseases are difficult or not at all treatable at the current level of development of medicine. They are transmitted from person to person through the blood, so the possible routes of entry of the viruses of these diseases include blood transfusion, a contaminated needle, and the genital tract. Based on this, the prevention of these deadly diseases includes the following measures:

1. observance of the rules of personal hygiene;

2. exclusion of promiscuity;

3.use of special methods of protection for sexual
connections;

4.use of disposable syringes;

5. sterilization of medical instruments.

quarantine is a complex of regime, administrative and sanitary anti-epidemic measures aimed at preventing the spread of infectious diseases and eliminating the focus of the lesion. If multiple cases of infectious diseases occur in a certain area, quarantine is imposed. During quarantine, it is possible to organize an armed cordon of the focus of infection, prohibition of movement outside the quarantine zone of persons and groups of the population without prior temporary isolation and medical supervision, removal of property from the focus without prior disinfection, as well as the passage of vehicles and people through the focus of the lesion.

During quarantine, contact between people is limited. Timely isolation of patients in the quarantine zone is one of the most important measures against the spread of infections in the focus of infection. Employees of medical institutions and other employees associated with constant communication with people take special measures to avoid mutual infection. One of these measures is special clothing. For example, a full anti-plague suit consists of overalls, a hood, boots, a cotton-gauze bandage on the nose and mouth, canned glasses, rubber gloves and a medical gown.

Observation called a set of measures that provide for enhanced medical monitoring of the lesion and the implementation of therapeutic and preventive and restrictive measures in it. If, as a result of research, pathogens of especially dangerous infections have not been identified in the outbreak and there is no threat of the spread of mass diseases, quarantine is replaced by an observation regime.

The period of quarantine and observation is determined by the duration of the maximum incubation period of the disease, calculated from the moment of isolation of the last patient and the end of disinfection in the outbreak.

The elimination of emerging foci of infectious diseases is carried out by the Russian Ministry of Emergency Situations, the Ministry of Health and Social Development of Russia, etc.

When an infectious disease occurs in the children's team sick child is isolated or hospitalized. The same is true for adults.

The institution conducts:

1) thorough disinfection using bleach preparations;

2) quarantine measures in a group or class (for a period equal to the maximum incubation period; patients are isolated for the entire period of contagiousness), during which it is impossible: a) to transfer children from group to group, from class to class; b) to accept in the group of children who have not been in contact with patients or who have not had this infection;

3) daily medical examination of children before admission to a group, class with thermometry;

4) administration of serum (gamma globulin) to contact, unvaccinated children;

5) current disinfection and ventilation;

6) inspection and examination of the personnel of the institution.

First aid for bites of rabid animals

When bitten by a dog or other animal, a number of urgent measures must be taken. Wash the wound immediately with warm soapy water. It is better to use household soap, it contains more alkali, and the virus is inactivated by alkalis. The best way to prevent rabies is to cause profuse bleeding from the wound. The virus that has entered the bloodstream is washed out by the blood flowing from the wound. If there is a strong suspicion of rabies in the biting animal (aggressive behavior, salivation, rabies, etc.), cut the wound with a knife or blade and squeeze as much blood out of the wound as possible. Contact the emergency room as soon as possible! Even if you were bitten by your own dog, cat or other pet, but you are not sure that the vaccination was done on time, be sure to consult a doctor, and take the animal to a veterinary clinic for examination and vaccination. In the emergency room, you are required to offer a course of anti-rabies treatment. Do not be afraid: 40 injections in the stomach have not been done for a long time. First, you will be given a vaccine along with an antiserum so that the antibodies it contains help destroy the virus. Then 5-6 more vaccine injections will be made in the shoulder according to a certain time schedule. This will allow the body to develop its own immunity against the rabies virus.

SDYAV. Scale prediction method1. GENERAL PROVISIONS

Potent toxic substances (SDN) are chemicals that are intended for use for national economic purposes and have a toxicity that can cause massive damage to people, animals and animals.

plants.

At a number of objects of the national economy, the production, use, storage and transportation of SDYAV is carried out. Violation of the rules for the technology of their production, storage and transportation, indiscipline of the attendants are the cause of emergency situations, disasters, leading to tragic consequences. Accidents with environmental pollution can also occur as a result of the destruction of objects of the national economy during military operations or sabotage, earthquakes, floods, landslides, fires, etc. can lead to the same results. natural disasters.

With outflows (emissions) of SDYAV, lesions are formed. Moreover, during hostilities or natural disasters occurring in the areas where enterprises manufacturing, using or transporting SDYAV are located, the likelihood of such foci of destruction greatly increases. They are usually divided into areas of direct outflow (release) of SDYAV, and zones of distribution of their vapors. An important characteristic of the lesions formed by SDYAV is the duration of the existence of areas of direct outflow (emission) of substances, i.e. resistance to infection. Most SDYAV having a boiling point of up to 20 C (chlorine, hydrogen sulfide, ammonia), as a rule, quickly evaporate, so the persistence of infection in the areas of their outflow (emission) is small. However, vapors of such substances, including those in dangerous concentrations, can be detected at large distances (up to several kilometers) from the place of their outflow (release).

The damaging effect of SDYAV is manifested as a result of their contact in a drop-liquid state on the skin of a person, as well as when their vapors are inhaled. The wind has a great influence on the evaporation of SDYAV vapors, therefore, in settlements, forests, on rough terrain, the resistance of infection with them will be higher than in the open.

1.1. This technique makes it possible to predict the extent of contamination zones in case of accidents at process tanks and storage facilities, during transportation by rail, pipeline and other modes of transport, as well as in the event of the destruction of chemically hazardous objects.

1.2. The methodology applies to the case of the release of SDYAV into the atmosphere in a gaseous, vaporous or aerosol state.

1.3. The scale of SDYAV infection, depending on their physical properties and state of aggregation, is calculated for the primary and secondary clouds:

for liquefied gases - separately for primary and secondary; for compressed gases - only for primary; for toxic liquids boiling above ambient temperature - only for secondary.

1.4. Initial data for predicting the scale of infection with SDYAV:

the total number of SDYAV at the facility and data on the placement of their stocks in process tanks and pipelines;

the amount of SDYAV released into the atmosphere, and the nature of their spill on the underlying surface (“loose”, “into a pallet” or “into a bunding”);

the height of the pallet or bunding of storage tanks;

meteorological conditions: air temperature, wind speed at a height of 10 m (at the height of the weather vane), degree of vertical air stability (Appendix 1).

1.5. When predicting the scale of infection in advance in case of industrial accidents, it is recommended to take as initial data: the release of SDYAV ( Q 0) - the number of SDYAV in the maximum unit capacity (technological, storage, transport, etc.) * , meteorological conditions - inversion, wind speed 1 m/s.

* For seismic regions - the total stock of SDYAV.

To predict the extent of infection immediately after the accident, specific data on the amount of released (spilled) SDYAV and actual weather conditions should be taken.

1.6. The external boundaries of the SDYAV infection zone are calculated according to the threshold toxodose during inhalation exposure to the human body.

Accepted assumptions

Thickness h liquid layer for SDYAV spilled freely on the underlying surface is assumed to be 0.05 m over the entire area of ​​the spill; for SDYAV spilled into a pallet or bunding, is determined as follows:

a) in case of spills from containers with an independent pallet (bunding):

h = H - 0,2,

where H- height of the pallet (bunding), m;

b) in case of spills from containers located in a group with a common sump (bunding):

where Q 0 - the amount of the substance thrown out (spilled) during the accident, t;

d- SDYAV density, t/m 3 ;

F- real spill area into the pallet (bunding), m 2 .

The maximum time for people to stay in the infection zone and the duration of meteorological conditions (the degree of vertical stability of the atmosphere, wind direction and speed) remain unchanged is 4 hours. After the specified time, the situation forecast must be updated.

In case of accidents on gas and product pipelines, the release of SDYAV is taken equal to the maximum amount of SDYAV contained in the pipeline between automatic cut-offs, for example, for ammonia pipelines - 275 - 500 tons.

1.8. Terms and Definitions

A potent toxic substance (SDN) is a chemical used in the national economy, which, when spilled or released, can lead to air pollution at the level of damaging concentrations.

SDYAV infection zone - the territory where the concentration of SDYAV reaches values ​​dangerous for human life.

By predicting the scale of SDYAV infection, we mean determining the depth and area of ​​the zone of SDYAV infection.

An accident is understood as a violation of technological processes in production, damage to pipelines, tanks, storage facilities, vehicles, leading to the release of SDYAV into the atmosphere in quantities that can cause mass injury to people and animals.

The destruction of a chemically hazardous facility should be understood as the result of catastrophes and natural disasters that led to the complete depressurization of all containers and disruption of technological communications.

Chemically dangerous object of the national economy - an object, in the event of an accident or destruction of which, mass destruction of people, animals and plants by potent toxic substances can occur.

Primary cloud - a cloud of SDYAV, formed as a result of an instantaneous (1 - 3 min) transition into the atmosphere of a part of the SDYAV from the container during its destruction.

Secondary cloud - a cloud of SDYAV, formed as a result of the evaporation of a spilled substance from the underlying surface.

Threshold toxodosis - inhalation toxodosis, causing the initial symptoms of the lesion.

An equivalent amount of SDYAV is understood as such an amount of chlorine, the scale of contamination of which, when inverted, is equivalent to the scale of infection with a given degree of vertical stability of the atmosphere by the amount of SDYAV transferred to the primary (secondary) cloud.

The area of ​​the zone of actual SDYAV infection is the area of ​​the territory infected with SDYAV within life-threatening limits.

The area of ​​the zone of possible infection with SDYAV is the area of ​​the territory within which, under the influence of a change in the direction of the wind, a cloud of SDYAV can move.

Magnitude scale

The magnitude scale distinguishes earthquakes by magnitude, which is a relative energy characteristic of an earthquake. There are several magnitudes and, accordingly, magnitude scales: local magnitude (ML); magnitude determined from surface waves (Ms); magnitude determined from body waves (mb); moment magnitude (Mw).

The most popular scale for assessing earthquake energy is the local Richter magnitude scale. On this scale, an increase in magnitude by one corresponds to a 30-fold increase in the released seismic energy. An earthquake with a magnitude of 2 is barely perceptible, while a magnitude of 7 corresponds to the lower limit of destructive earthquakes covering large areas. The intensity of earthquakes (cannot be estimated by magnitude) is estimated by the damage they cause in populated areas.

The Richter scale is a magnitude classification of earthquakes based on an estimate of the energy of seismic waves that occur during earthquakes. The scale was proposed in 1935 by the American seismologist Charles Richter (1900-1985), theoretically substantiated jointly with the American seismologist Beno Gutenberg in 1941-1945, and has become widespread throughout the world.
Earthquakes of different magnitudes (on the Richter scale) manifest themselves as follows:
2.0 - the weakest felt shocks;
4.5 - the weakest shocks, leading to minor damage;
6.0 - moderate destruction;
8.5 is the strongest known earthquake.
11 Smog, acid rain and its impact on human health.

Smog (from English. smoky fog, literally - "Smoke fog") - an aerosol consisting of smoke, fog and dust, one of the types of air pollution in large cities and industrial centers. There are three types of smog: ice smog(Alaskan type); wet smog(London type); dry, or photochemical smog(pre-Angers type). Wet smog is the most studied. It is common in places with high relative humidity and frequent fogs. This contributes to the mixing of pollutants, their interaction in chemical reactions. These pollutants are directly emitted into the atmosphere, they are called primary pollutants. The main toxic components of wet smog are most often CO2 and SO2. Infamous case, worm in 1952 wet smog in London claimed more than 4,000 lives.
Photochemical smog is a secondary air pollution that occurs during the decomposition of primary pollutants by sunlight. The main toxic component is ozone.
Ice smog occurs at very low temperatures and an anticyclone. In this case, emissions of even a small amount of pollutants lead to the formation of a thick fog, consisting of tiny ice crystals and, for example, sulfuric acid.

Health impact

Smog is a big problem in many cities around the world. It is especially dangerous for children, the elderly and people with heart and lung defects, bronchitis, asthma, emphysema. Smog can cause shortness of breath, difficulty and cessation of breathing, insomnia, headaches, cough. It also causes inflammation of the mucous membranes of the eyes, nose and larynx, and a decrease in immunity. Smog often increases the number of hospitalizations, relapses and deaths from respiratory and cardiac diseases.

Acid rain- all types of meteorological precipitation: rain, snow, hail, fog, sleet, in which there is a decrease in the pH of rainfall due to air pollution with acidic oxides, usually: sulfur oxides, nitrogen oxides. They are formed during industrial emissions of sulfur dioxide and nitrogen oxides into the atmosphere, which, when combined with atmospheric moisture, form sulfuric and nitric acids. As a result, rain and snow are acidified (pH value below 5.6 ). Impact acid rain per person is also not only direct. Of course, the microparticles of sulfates and nitrates contained in the air increase the risk of an asthma attack, bronchitis, and harm the cardiovascular system. But no less dangerous for humans are the destruction of crops and pastures, the death of commercial fish caused by acid precipitation. First of all, the danger is determined by the size of these particles. Large particles are mainly stopped by the upper respiratory tract, and small ones (droplets that consist of a mixture of nitric and sulfuric acids can penetrate the lungs and cause damage there. In addition, heavy metals can enter human food, which can lead to poisoning.

Preparing for an earthquake.

Everyone living in an earthquake-prone area must consciously and systematically plan their actions during a possible earthquake. You are much more likely to remain calm and able to act rationally if you think through everything in advance - your actions in various conditions and places, during the day, at night, at home, at work, in public places (shop, theater), in transport, at a party and in other places where you visit.
The following are activities that can be done. Some of them are the simplest measures that can be taken immediately, other recommendations are addressed to those who are willing to spend their time and effort to provide additional security.
HOUSES
1. Have a detailed discussion with your family about the possibility of an earthquake, make and ask the family to remember well the plan for gathering the whole family after an earthquake. Mark the collection point in an open area near the house.
2. Plan in advance the most economical and safe way out of the premises in case of an earthquake. Remember that it can happen at night when the lights are off, stairwells, corridors, doors will be clogged with people. The door can also jam.
3. Determine in advance the safest places in the apartment (house): internal corners of the main walls and openings of entrance doors, places under the beams of the building frame (seismic belt), tables, beds.
4. Teach children and other members of your family to take a safe place.
5. Check the condition of your home - ceilings, roofing, chimney, electrical wiring and gas pipes. Determine what measures are required to strengthen it.
6. Provide in the apartment (house) the possibility of a quick exit, remove unnecessary, interfering things from the corridors and aisles.
7. Attach bulky furniture and bookcases, mezzanines and other heavy objects to the walls and floor, securely fasten chandeliers and other lighting fixtures.
8. Remember, it is necessary to strengthen and place cabinets, shelves, furniture so that in case of a fall they do not block the exit, do not close the door.
9. Sleeping places should be located away from large windows, glass partitions, mirrors and heavy objects that can fall. Above beds and sofas do not hold shelves, heavy paintings.
10. It is advisable not to store flammable or poisonous liquids in the apartment, or store them in a safe place where they cannot spill.
11. Have a first aid kit ready and know how to provide it. If you are constantly taking any medications, keep a supply of them.

12. Always have a battery-powered radio, a flashlight and a supply of batteries for them, and matches at the ready.
13. Find out how gas, electricity and water are turned off in your apartment (house). If a wrench is needed to shut off the line, place or tie it close to the valve to be closed.
14. It is advisable to store documents, particularly valuable items and articles made of precious metals in a place in a bag so that, if necessary, you can quickly take them with you.
15. When stocking up on canned foods and drinks, plan for the first 3 to 5 days. All this can be put in a backpack or bag and stored in a conspicuous place.
AT WORK
1. Develop an earthquake action plan. Determine the responsibilities of each member of the team - who and what should do or not interfere with others.
2. Learn and have a solid knowledge of the collection and action according to the plan and your responsibilities. Remember that in the event of an earthquake, the collection notification is not carried out due to possible damage to communications equipment and the time limit for this.
3. Develop instructions for civil protection formations to take the necessary measures in case of an earthquake.
4. Maintain order in buildings, workshops, workshops, do not clutter up corridors and aisles, stairwells. Check that the outer doors can be quickly and easily unlocked and opened from the inside.
5. Prepare spare doors, gates, windows of the lower floors, additional passages at checkpoints for quick opening.
6. Attach heavy cabinets and racks securely to floors and walls, do not place heavy items on the upper shelves.
7. Study and remember the location of fire hydrants and posts, electric switches, gas and water main taps, often check their serviceability.
IN MEDICAL INSTITUTIONS
1. Instruct incoming patients for treatment about the rules of behavior and their actions during an earthquake. Indicate to them the places of shelters in the wards and rooms, the way out.
2. Determine the responsibilities of medical and attendant personnel in carrying out protective and sedative measures for seriously ill patients.
3. Place sick beds away from large windows and glass partitions.
4. Develop measures to continue or stop surgical and other surgical and instrumental interventions.
IN PRESCHOOL AND SCHOOL INSTITUTIONS
1. Instruct teachers and technical staff about their actions in case of an earthquake.
2. Explain in detail to the children what to do if an earthquake hits them at school.
3. Put in order the corridors and emergency exits, the windows of the first floors.
4. Parents: Promise children that after an earthquake, you will immediately take them home.
5. Support the idea of ​​seismic alarms, activities and training, while carefully protecting the children's psyche by introducing elements of the game into the rules of behavior during an earthquake, combined with instilling a sense of responsibility. Don't make your children fear earthquakes.

Fractures. First aid.

fracture is a traumatic violation of the integrity of the bone as a result of mechanical stress or disease. Fractures are divided into open and closed. Signs of a closed fracture: the skin is not broken, swelling is observed at the fracture site, the natural position of the limb is disturbed. With an open fracture, the integrity of the skin is broken, an open wound is formed.

Additional signs by which the presence of a fracture is determined: a crunch at the site of a closed fracture; fragments of bones in the wound with an open fracture; swelling of soft tissues, subcutaneous hemorrhage; dysfunction of the injured limb. Severe pain accompanying fractures can provoke pain shock, a very dangerous condition that can lead to the death of the patient. The state of shock is characterized by general depression, inhibition of body functions and a state of weakness.

First aid for fractures:

If you witness an accident resulting in a fracture, call immediately ambulance. Doctors will provide first aid, alleviate the patient's condition. Examine the patient before the arrival of the ambulance. If a fracture of the spine is suspected, it is advisable not to touch the patient so as not to displace the vertebral discs. If transportation is still necessary, the patient should be laid belly down on a board covered with something soft. With a fracture of the spine, paralysis of the legs, urination disorder can occur.

If the spine is intact, gently move the patient to a safe area. Examine the fracture and provide first aid. If there is bleeding, apply a tourniquet using any available means (rope, tie), placing some tissue under it. The tourniquet is applied above the site of bleeding, no more than two hours.

The doctor should be warned about the time of applying the tourniquet. Next, the patient needs to immobilize the limb with the help of any improvised materials (planks or sticks). An impromptu splint is placed on two joints, above and below the fracture. If the shoulder or hip joint is injured, the splint should fix three joints.

After application, the splint is bandaged with pieces of cloth, clothing, or any other means at hand. When applying a splint, do not try to connect the broken bones, just fix the limb motionless. To avoid the pressure of the tire on the bony protrusions, it is necessary to put something soft under it (cotton wool, handkerchiefs).

rescue work

a system of measures carried out by specially formed units and aimed at saving people, material and cultural values, protecting the natural environment in the emergency zone, localizing the emergency, suppressing or bringing to the minimum possible level the impact of hazardous factors that threaten human life and health. S.r. include the following activities: reconnaissance of the emergency zone, search and release of victims, provision of first aid to them, evacuation from the affected area and their life support. In carrying out S.r. troops and formations of civil defense, units of the search and rescue service and the disaster medicine service, fire protection services, as well as the formation of departmental rescue services can take part.

HIV infection. AIDS.

HIV is the human immunodeficiency virus, which is the causative agent of the disease called HIV infection. This disease has several stages, the last of which is called AIDS.

AIDS - acquired immunodeficiency syndrome: syndrome - a set of signs and symptoms of a given disease, acquired - not genetically determined, but obtained in the course of life, deficiency - a disadvantage, in this case, in the work of the immune system, immunodeficiency - damage to the immune system, its inability to resist infections.

Immunity is a special function of the human body to protect itself from living bodies and substances that bear signs of genetically alien information. The immune system produces specific molecules - antibodies to fight various pathogens and foreign substances (antigens).

In official terms, infection can occur when infected blood enters the bloodstream of an uninfected person (by injection with a non-sterile syringe, transfusion of infected blood products) or through sexual contact. When infected sexually, the virus enters the body through the mucous membranes of the vagina, penis, rectum, or, much less often, the oral cavity. It is also possible to infect an infant from the mother during pregnancy (intrauterine), during childbirth or during breastfeeding. No other routes of HIV infection have been reported.

Doctors consider domestic infection impossible, since HIV can live outside the body for only a few minutes. However, to prevent injection transmission of HIV, it should be assumed that a used syringe may contain live virus for several days.

It is impossible to get HIV through hugs and handshakes. Intact skin is a barrier to the virus. For a theoretical risk of transmission of HIV through a handshake, a sufficient amount of blood containing HIV must enter a fresh open wound.

HIV is found only in blood, semen, vaginal secretions and breast milk. Through clothes, bed linen, towels, HIV cannot be transmitted, even if liquid containing HIV has got on the clothes, linen. It dies too quickly outside of a person. During the 20 years of the epidemic, no cases of household transmission of HIV were observed, and observations were also made in couples where one partner is HIV positive and the other is HIV negative.

You cannot get infected with HIV in a pool, bath, bath. If a liquid containing HIV enters the water, the virus will die, and again, the skin is a reliable barrier against the virus. The only way to get HIV in a pool is to have sex there without a condom.

HIV is not transmitted through insect bites or other contact with animals. HIV is a human immunodeficiency virus, it can live and multiply only in the human body. Animals cannot transmit HIV. Human blood cannot get into someone else's bloodstream even when bitten by a mosquito. HIV is not able to multiply in the body of a mosquito or any other bloodsucker, therefore, even if it enters the body of an insect, it does not survive and cannot infect anyone.

You can't get HIV through kissing either. The risk of HIV infection during testing or surgery with properly performed sterilization (and the presence of gloves at the doctor) is excluded.

HIV infection is characterized by a long-term course with a progressive decrease in immunity, leading to the development of severe forms of opportunistic and oncological diseases. Until now, it is believed that in the vast majority of cases, HIV infection has one single outcome - the death of an HIV-infected organism. However, the general theory of the infectious process allows for the existence of both less infectious or defective strains of HIV, and patients resistant to infection.

During HIV infection, several periods can be distinguished: the incubation period; the period of early clinical manifestations; latent period; the period of development of secondary diseases and the terminal period. It should be noted that an infected person is contagious at all stages of the development of the disease, but especially in the acute period and in the stage of AIDS, when the virus is actively multiplying in the body.

Most often, AIDS occurs in the pulmonary form (in 50–80% of patients), which manifests itself in the development of pneumonia, which is much more severe than in uninfected HIV, in a special form - pneumocystis.

Many patients develop an intestinal form, which manifests itself in the form of prolonged (for several months), but not very intense diarrhea, which leads to a loss of body weight by more than 10% and dehydration of the patient's body. Gastrointestinal diseases in AIDS are usually caused by yeast-like fungi of the genus Candida (candidiasis), tuberculosis bacteria, salmonella, cytomegaloviruses. The chronic form of dysentery may become aggravated. The manifestations of these diseases can be very diverse.

Treatment of HIV-infected and AIDS patients consists in suppressing the virus, in combating opportunistic infections and oncological diseases that occur against the background of reduced immunity, as well as in stimulating the immune system.

The main problems faced by doctors in the treatment of HIV infection were the high toxicity of drugs and the high adaptability of the virus to these drugs. Therefore, combination therapy has been proposed for treatment. Antiretroviral therapy (ARVT) involves the use of three (at least two) drugs to stop HIV from multiplying. Currently, three groups of drugs are known: the first and second are drugs that act on the reverse transcriptase enzyme and prevent the transfer of virus RNA information to host cell DNA; the third group - these are drugs that act on another HIV enzyme - protease, prevent the formation of full-fledged HIV particles.

Burns, degrees of burns.

Burn - damage to body tissues caused by the action of high temperature or the action of certain chemicals (alkalis, acids, salts of heavy metals, etc.).

There are four degrees of burns. The severity of the injury depends on the temperature of the object, the duration of contact with it, the depth of tissue damage and the size of the burned area of ​​the body.

1st degree burn;

2nd degree burn;

3rd degree burn;

Burn 4 degrees.

Degrees of burns

First-degree burns are superficial burns that cause only reddening of the skin. The most common first-degree burn is sunburn. First-degree burns can be very painful, but are not serious, even if they are extensive. They rarely lead to long-term complications and rarely require medical attention.

Second-degree burns cause the surface layer of the skin to peel off and form blisters. Most often, such burns are caused by scalding with hot water and very strong sunburn. Second-degree burns are very painful and often cause severe general impairment. Scarring at the site of such burns usually does not form, and infection is rare.

Third and fourth degree burns damage all layers of the skin and penetrate deeper tissues. There may be charring of the burnt area. This area may be painless as the nerve endings die. True, often painless third or fourth degree burns can be surrounded by painful areas with second degree burns. These burns result in

inhalation

10. The level of air pollution of the working area with a toxic substance is determined by the multiplicity of excess of the measured concentration in relation to:

11. The parameter characterizing the level of natural light is the coefficient:

natural light

12. The blinding effect of the light source is evaluated:

blindness

What indicator is not taken into account when rationing natural and combined lighting?

coloring of the background on which the object of difference is viewed, and contrast

14. The pressure difference that occurs in a perturbed and unperturbed elastic medium is called:

sound pressure

15. When sanitary and hygienic regulation of noise, the following indicator is taken into account:

the severity and intensity of the labor process

16. Reducing the level of aerodynamic noise is achieved using:

mufflers

17. Rationing of vibration velocity levels is carried out according to the following frequencies of octave bands:

geometric mean

18. Alternating current with a frequency of 50 Hz and a value of 810 mA when passing through the human body is:

restraining

19. When carrying out repair work on an electrical installation, in addition to turning off the knife switch, to prevent electric shock electricians, the following should be additionally provided for:

warning posters

20. The principle of operation of protective grounding is based on:

reducing the voltage between the energized housing and earth to a safe value

21. Easily flammable liquids (flammable liquids) with a flash point of less than - 18 ° C belong to:

especially dangerous

22. The introduction of an inert gas into an explosive mixture of combustible gas with air:

narrows the ignition range

23. The zone in which an explosive concentration of aerosol constantly exists under normal conditions of the technological process, in accordance with the PUE, is designated as:

24. According to the degree of explosion and fire hazard, a boiler house operating on natural gas belongs to the category:

25. For automatic extinguishing of a fire that has arisen at enterprises, the following are provided:

deluge installations

Ticket number 19

1. Children's games in quarries, near roads, on the territory of a facility under construction, on ice, etc. are associated with a risk:

on a conscious

2. The level of risk after the implementation of protective measures is called:

minimal

3. Ensuring the rights of the employee to labor protection and guarantees of these rights are enshrined in the documents:

4. Workplace with dangerous working conditions:

subject to liquidation

5. Rationing of microclimate parameters is carried out according to a set of indicators:

temperature, relative humidity and air velocity in the working area

6. The "hot shop" includes a room in which the minimum value of the specific excess of sensible heat is equal to:

7. The combined action of microclimatic parameters on the human body is evaluated by the parameter:

thermal load of the environment

8. In the direction of the air flow, ventilation is divided into:

supply and exhaust

9. With a long-term intake of a harmful substance into the human body in relatively small quantities, the following may develop:

chronic poisoning

10. Systematic work in conditions of high levels of dust content in the air can lead to:

pneumoconiosis

11. KVIO is a coefficient:

possible inhalation poisoning

12. The gravimetric method of analysis allows you to determine the concentration in the air of the working area:

aerosols

13. The level of air pollution in the working area and the magnitude of the risk of ill health when working with harmful substances are established based on:

the multiplicity of excess of the actual concentration of a harmful substance over the MPKRP

14. The unit of measurement of the coefficient of natural light is:

15. Lighting of industrial premises with lamps with two or more fluorescent lamps is primarily due to the fact that:

reduce the pulsation of the light flux

What kind of advantages are not typical for fluorescent lamps?

independence of light output from temperature

17. Sound intensity is:

the amount of energy carried by a sound wave per unit time per unit area

18. When sanitary and hygienic regulation of noise at workplaces, the following is taken into account:

subjective perception of noise by a person

19. Foam rubber, polystyrene, fiberglass are materials related to:

sound-absorbing

20. The main normalized parameter, taking into account the degree of danger of vibration, is:

vibration velocity level

21. Fatal for a person is the value of alternating current with a frequency of 50 Hz:

22. A person touching one phase during normal operation of electrical equipment is less dangerous in a network with a neutral type:

does not depend on the type of neutral

23. Protective grounding of equipment is mainly used in networks with voltage up to 1000 V:

in a network with a neutral wire with an isolated neutral

24. Easily flammable liquids (flammable liquids), having a flash point of more than -18 ° C to 23 ° C, according to the degree of explosion hazard, are liquids:

constantly dangerous

Section 1 Question 5

Harmful substances, ways of their penetration into the human body. Classification of harmful substances. The principle of determining MPC. Means of collective and individual protection against damage by harmful substances of various types.

Harmful substances- substances that adversely affect the human body and cause disruption of normal life processes. Exposure to harmful substances can result in acute or chronic poisoning of workers. Harmful substances can enter the human body through the respiratory system, gastrointestinal tract, skin, and also through the mucous membranes of the eyes. Excretion of harmful substances from the body occurs through the lungs, kidneys, gastrointestinal tract and skin. The toxic effect of harmful substances depends on a number of factors: gender and age of workers, individual sensitivity of the body, the nature and severity of the work performed, meteorological conditions of production, etc. Some harmful substances can have a harmful effect on the human body not at the time of their exposure, but after many years and even decades (long-term consequences). The manifestation of these influences can also be reflected in the offspring. Such negative effects are gonadotropic, embryotoxic, carcinogenic, mutagenic effects, as well as accelerated aging of the cardiovascular system. All harmful substances are divided according to danger into four classes: 1st - extremely dangerous (maximum concentration limit 0.1 mg / m 3); 2nd - highly dangerous (0.1 MPC 1 mg / m 3); 3rd - moderately dangerous (1 MAC 10 mg / m 3; 4th - low-hazard (MAC 10 mg / m 3).

According to the degree of impact on the human body harmful substances in accordance with GOST 12.1.007 SSBT " Harmful substances. Classification and general safety requirements are divided into four hazard classes:
1 - extremely dangerous substances (vanadium and its compounds, cadmium oxide, nickel carbonyl, ozone, mercury, lead and its compounds, terephthalic acid, tetraethyl lead, yellow phosphorus, etc.);
2 - highly hazardous substances (nitrogen oxides, dichloroethane, karbofos, manganese, copper, hydrogen arsenic, pyridine, sulfuric and hydrochloric acids, hydrogen sulfide, carbon disulfide, thiuram, formaldehyde, hydrogen fluoride, chlorine, caustic alkali solutions, etc.);
3 - moderately hazardous substances (camphor, caprolactam, xylene, nitrophoska, low-pressure polyethylene, sulfur dioxide, methyl alcohol, toluene, phenol, furfural, etc.);
4 - low-hazard substances (ammonia, acetone, gasoline, kerosene, naphthalene, turpentine, ethyl alcohol, carbon monoxide, white spirit, dolomite, limestone, magnesite, etc.).
The degree of danger of harmful substances can be characterized by two toxicity parameters: upper and lower.
Upper toxicity parameter characterized by the lethal concentrations for animals of various species.
Lower- minimum concentrations that affect higher nervous activity (conditioned and unconditioned reflexes) and muscle performance.
Practically non-toxic substances usually they name those that can become poisonous in quite exceptional cases, under such a combination of various conditions that does not occur in practice.

Collective protection means- protective equipment, structurally and functionally associated with the production process, production equipment, premises, building, structure, production site.

Depending on the purpose, there are:

• means of normalizing the air environment of industrial premises and workplaces, localizing harmful factors, heating, ventilation;
• means of normalizing the lighting of premises and workplaces (light sources, lighting fixtures, etc.);
• means of protection against ionizing radiation (protective, sealing devices, safety signs, etc.);
• means of protection against infrared radiation (protective, sealing, heat-insulating devices, etc.);
• means of protection against ultraviolet and electromagnetic radiation (protective, for air ventilation, remote control, etc.);
• means of protection against laser radiation (fencing, safety signs);
• means of protection against noise and ultrasound (fencing, noise silencers);
• means of protection against vibration (vibration isolating, vibration damping, vibration absorbing devices, etc.);
• means of protection against electric shock (fences, alarms, isolating devices, grounding, grounding, etc.);
• means of protection against high and low temperatures (fences, thermal insulating devices, heating and cooling);
• means of protection against the impact of mechanical factors (fencing, safety and braking devices, safety signs);
• means of protection against the effects of chemical factors (devices for sealing, ventilation and air purification, remote control, etc.);
• means of protection against biological factors (fencing, ventilation, safety signs, etc.)

Collective means of protection are divided into: protective, safety, braking devices, automatic control and signaling devices, remote control, safety signs.

1) Protective devices designed to prevent accidental entry of a person into the danger zone. These devices are used to isolate moving parts of machines, processing areas of machine tools, presses, impact elements of machines from the working area. Devices are divided into stationary, mobile and portable. They can be made in the form of protective covers, visors, barriers, screens; both solid and mesh. They are made from metal, plastic, wood.

Stationary fences must be strong enough and withstand any loads arising from the destructive actions of objects and the disruption of workpieces, etc. Portable fences in most cases are used as temporary.

2) Safety devices. They are designed to automatically turn off machines and equipment in case of any deviation from the norms of the operating mode or if a person accidentally enters the danger zone. These devices are divided into blocking and restrictive devices.

Blockers devices according to the principle of operation are: electromechanical, photoelectric, electromagnetic, radiation, mechanical.

Limiting devices are components of machines and mechanisms that are destroyed or fail when overloaded.

3) Brake devices. By design, such devices are divided by type into shoe, disc, conical, wedge brakes. They can be manual (foot) drive, semi-automatic and fully automatic drive. These devices, according to the principle of purpose, are divided into service, reserve, parking brakes and emergency braking devices.

4) Automatic control and alarm devices are essential to ensure proper safety and reliable operation of the equipment. Control devices are various kinds of measuring sensors for pressure, temperature, static and dynamic loads on equipment. The efficiency of their use is greatly increased when combined with alarm systems. According to the method of operation, the alarm system is automatic and semi-automatic. Also, the alarm can be informational, warning and emergency. Types of information signaling are various kinds of schemes, signs, inscriptions on equipment or displays, directly in the service area.

5) Remote control devices most reliably solve the problem of ensuring safety, as they allow you to control the necessary operation of the equipment from areas that are outside the danger zone.

6) Safety signs carry the necessary information to avoid accidents. They are subdivided according to GOST R 12.4.026-2001 SSBT. They are
can be basic, additional, combined and group:

• Main - contain an unambiguous semantic expression of the requirements for
  security. The main signs are used independently or as part of combined and group safety signs.
• Additional - contain an explanatory inscription, they are used in
  combined with the main signs.
• Combined and group - consist of basic and additional characters and are carriers of comprehensive security requirements.

Safety signs according to the types of materials used can be non-luminous, retroreflective and photoluminescent. Safety signs with external or internal lighting must be connected to an emergency or autonomous power supply.

Signs with external or internal electric lighting for fire and explosion hazardous premises must be made in a fireproof and explosion-proof design, respectively, and for fire and explosion hazardous premises - in an explosion-proof design.

Safety signs intended for placement in production environments containing aggressive chemical environments must withstand exposure to gaseous, vaporous and aerosol chemical environments.

Personal Protective Equipment (PPE)- designed to protect against ingress into the body, on the skin and clothes of radioactive and toxic substances, bacterial agents. They are divided into respiratory and skin PPE. These also include an individual anti-chemical package and an individual first aid kit.

Respiratory protection equipment includes:

• Gas masks
• Respirators
• Anti-dust sheet mask
• Cotton-gauze bandage

The main means of protection is a gas mask designed to protect the respiratory organs, face and eyes of a person from the effects of toxic substances in the form of steam, radioactive substances, pathogenic microbes and toxins. According to the principle of action, gas masks are divided into filtering and insulating. The anti-dust respirator is used to protect the respiratory organs from dust. It can be used when acting in the focus of bacteriological contamination to protect against bacterial aerosols. The respirator is a filtering half mask equipped with two inhalation and one exhalation valves. Anti-dust fabric masks consist of a body and a mount. The body is made of 4-5 layers of fabric. Coarse calico, staple fabric, knitwear are suitable for the top layer; for the inner layers - flannel, cotton or woolen fabric with a fleece. For cotton-gauze dressing use a piece of gauze measuring 100 by 50 cm. A layer of cotton wool measuring 100 by 50 cm is applied to its middle. In the absence of a mask and bandage, you can use a fabric folded in several layers, a towel, a scarf, a scarf, etc. According to the principle of protective action, RPE and SIZK are divided into filtering and insulating. Filtering filters supply air from the working area purified from impurities into the breathing zone, insulating - air from special containers or from a clean space located outside the working area.

Insulating protective equipment should be used in the following cases:

• in conditions of a lack of oxygen in the inhaled air;
• in conditions of air pollution in high concentrations or in the case when the concentration of pollution is unknown;
• in conditions where there is no filter that can protect against contamination;
• in case of heavy work, when breathing through the filter RPE is difficult due to the resistance of the filter.

If there is no need for insulating protective equipment, filter media must be used. The advantages of filter media are lightness, freedom of movement for the worker; ease of decision when changing jobs.

The disadvantages of filter media are as follows:

• filters have a limited shelf life;
• difficulty breathing due to filter resistance;
• limited work with the use of a filter in time, if we are not talking about a filtering mask, which is equipped with blowing.

You should not work with the use of filtering PPE for more than 3 hours during the working day. Insulating skin protection products are made from airtight, elastic frost-resistant materials in the form of a set (overalls or cape, gloves and stockings or boots). They are used during work in conditions of severe contamination with RS, OM and BS during special treatment. Overalls serves to protect the body of workers from the adverse effects of mechanical, physical and chemical factors of the production environment. Overalls should reliably protect against harmful production factors, not disturb the normal thermoregulation of the body, provide freedom of movement, wear comfort and be well cleaned of dirt without changing their properties. Special footwear must protect the feet of workers from the effects of hazardous and harmful production factors. Safety shoes are made of leather and leather substitutes, dense cotton fabrics with polychlorinated vinyl coating, rubber. Instead of leather soles, leatherette, rubber, etc. are often used. In chemical industries, where acids, alkalis and other aggressive substances are used, rubber shoes are used. Also widely used are plastic boots made from a mixture of polyvinyl chloride resins and synthetic rubbers. To protect the foot from damage caused by castings falling on the feet And forgings shoes are supplied with a steel toe that can withstand impact up to 20 kilograms. Protective dermatological agents serve to prevent skin diseases when exposed to certain harmful production factors. These protective agents are produced in the form of ointments or pastes, which are divided by purpose into: