Thermal effects: sources, effects and protection. Thermal effects Thermal effects on the human body
In the premises of the technical complex, when the spacecraft and launch vehicle are in them, the air temperature is ensured from 8 to 25 ° C and relative humidity from 30 to 85% at 25 ° C.
During transportation of a spacecraft with a launch vehicle from the technical to the launch complex, the temperature of the environment under the nose fairing can be ensured in the range from 5 to 35°C by special means (a heating unit placed on a moving railway platform and a thermal cover).
When the launch vehicle is on the launcher, the thermal regime of the environment under the fairing is ensured in the range from 5 to 35 °C by a refrigeration and heating unit located on the service unit and a thermal cover.
The refrigeration and heating unit is connected to the fairing by flexible air ducts that ensure air circulation in a closed loop (Fig. 10.1).
The refrigeration-heating unit supplies air at the inlet to the subflow space with a temperature of:
· when cooling 3 – 5 °C;
· when heated to 40 – 50 °C.
The amount of supplied air is 6000 - 9000 m 3 /h.
The air temperature at the inlet and outlet of the head fairing is controlled by means of a refrigeration and heating unit with an accuracy of 4°C.
Thermostating stops 90 minutes before the start of the launch vehicle.
The temperature of the subflow space immediately at the moment of launch of the launch vehicle depends on the weather conditions in the area of the launcher (temperature and wind speed, presence of precipitation, etc.)
Res. 10.1. The symmetry of the world
The thermal impact on a spacecraft during flight in the active part of the trajectory is due to various reasons.
Before the nose fairing is released, the spacecraft is heated under the influence of heat flow from the inner surface of the fairing. It is a consequence of heating of the fairing shell, mainly due to friction with the air, when passing through dense layers of the atmosphere at high speed.
The temperature field of the head fairing shell is significantly uneven. Its conical part is the hottest. The cylindrical part of the fairing, due to the high thermal conductivity of the materials of the power set and the shell itself, is heated relatively evenly. Therefore, to assess the degree of thermal impact on the spacecraft from the cylindrical part of the fairing, the average value of the heat flux can be used.
The amount of heat flow from the fairing depends on the emissivity coefficient (e) of the inner surface and changes over the flight time, reaching a maximum value at approximately 130 seconds. The nose fairing is usually released at an altitude of about 75 kilometers at a velocity pressure of about 14 kg/m 2 . In this case, the maximum heat flux for the fairing (manufactured with a coefficient e £ 0.1) does not exceed 250 W/m2.
After the nose fairing is dropped, the spacecraft is heated under the influence of the total heat flow due to collisions with air molecules and atoms and the recombination of oxygen atoms. This thermal effect can be assessed by the value of the heat flux density on the surface of the spacecraft, perpendicular to the velocity vector.
The thermal impact on the spacecraft after the nose fairing is dropped depends on the shape and size of the spacecraft, as well as on the type of launch of the spacecraft (propelled or target). In this regard, the magnitude of the thermal impact on the spacecraft is finally clarified individually for each spacecraft, taking into account its design features and program excretion.
The heat flux to the side surfaces of the spacecraft usually does not exceed 100 W/m2.
Stressful impact. Sufficient thermal procedures, especially baths, have a stressor effect on the human body. If you use this wisely, you can activate your defenses and strengthen your body. Thus, a moderate bath shakes, renews, and tones the human body. That is why you leave the bathhouse in a great mood. Elderly people especially need such a physiological shake-up. This will significantly activate their body, maintaining vigor and strength until old age.
On the skin. Exposure to heat (as well as cold) on the skin means:
a) effects on the largest organ in the human body. The skin makes up about 1.5 mg of tissue, 20% of a person's total weight;
b) impact on natural defenses. Our skin is the “front line of defense” of the human body. Comes into direct contact with the environment. Protects our blood vessels, nerves, glands, internal organs from cold and overheating, from damage and microbes. The skin contains the substance lysozyme, which is harmful to many bacteria;
c) effects on the respiratory and water-excretory function of the skin. The skin breathes, which means it helps the lungs. Water is released through it, which makes it easier for the kidneys to work. With its help we free ourselves from toxins;
d) effects on the sebaceous glands. The sebaceous glands have an outlet in the form of pores, lubricating our skin with a thin layer of a special emulsion that softens, protects it from drying, gives elasticity, firmness and shine. If the sebaceous glands function poorly, then the skin suffers, and the body suffers along with it;
d) protection against infections. In the fight against infection, the human body is capable of producing antibodies - an antidote that not only kills bacteria, but also disinfects the poisons they secrete. This protection continues to operate even when you recover. This is how immunity to the disease arises - immunity, in the formation of which, as recent research has shown, the skin is most actively involved. But the skin can only do this when it is clean and healthy. Clean, healthy skin counteracts the continuous aggression of microbes. Infection through the skin is possible only when it is contaminated. Research by scientists has shown that microorganisms on clean skin quickly die;
f) formation of dirt on the skin. Recently, Danish microbiologists discovered mites with a diameter of only 30 microns in dust, feeding on dead particles of human skin and causing a form of asthma. Mixing with sweat, with the constantly secreted sebum and flakes of the dead stratum corneum, these dust particles form what we call dirt. Dirty skin loses elasticity and becomes defenseless. Inflammation and suppuration are most often caused by staphylococci;
g) causes of skin diseases. Many skin diseases are the causes of the release of toxic contents of the body from the inside to the outside. This is how the body fights against toxic substances accumulated in it if the excretory organs cannot cope. Therefore, so that the heat of the bath does not act on the skin like a “vacuum cleaner” through which the toxic contents of the body are removed, carry out a preliminary cleansing of all the most important systems of the body - the intestines, liver, liquid media;
h) cleansing. Strong, pleasant heat (baths), like no other hygienic product, opens and thoroughly cleanses all the pores of the body and removes dirt. Gently removes old, dead cells from the top layer of skin. It is useful to know that in just one day, on average, a twentieth of a person’s skin cells die and are restored. This is how the moist heat of the bath helps skin self-renewal;
i) bactericidal effect of heat. The heat of a sauna and steam bath is bactericidal. In this heat, microbes on the human body also die;
j) cosmetic effect. Hot and wet procedures increase blood flow and train the vessels adjacent to the skin. This not only makes the skin look more attractive, but also improves its physiological properties. She is not afraid of temperature changes. In addition, her tactile ability increases.
Saturation of the body with moisture and warmth. One of the features of the phenomenon of life is the constant struggle of the body to maintain the optimal amount of moisture and heat. Judge for yourself: a three-day human embryo consists of 97% water, an adult - almost two-thirds of its weight, and an old person - even less. Under normal conditions, an adult exhales about 25.5 g of water in 1 hour (this is about 600 g per day). Over the years, any person loses water and warmth, and with them vitality. A wet bath procedure allows the human body to replenish both. As a result, vital manifestations in the human body are restored. This is especially useful for elderly and old people.
Effect on blood circulation in general. As previously stated, heat greatly stimulates circulatory processes in the body. The main circulating fluid in the body is blood. Therefore, the activity of the heart is activated, blood quickly circulates throughout the body, irrigating all organs and systems without exception. That is why simple warming up helps to get rid of blood stagnation simply and effectively. Health and the body’s resistance to external and internal unfavorable factors largely depend on blood exchange. And with age, blood circulation tends to decrease. Thus, after examining blood circulation in 500 people, it was found that on average, in 18-year-olds, 25 cm3 of blood passes through 1.5 cm3 of muscles. By the age of 25, the amount of blood circulating in the muscles decreases by almost half. Blood supply to the muscles is especially reduced in those who lead a sedentary lifestyle. What is especially valuable is that as a result of heating the body, reserve blood comes into motion, of which a person has 1 liter (out of 5-6 liters). Reserve blood, rich in valuable nutrients, provides excellent nutrition to the body's cells. As the body begins to warm up, blood pressure rises slightly. And then - thanks to the expansion of blood vessels - it decreases.
The effect of heat on capillary circulation. If we consider the circulatory system, then the capillaries contain 80% of all circulating blood in the body. The total length of the capillaries is about 100 thousand kilometers. The capillary system represents a kind of vascular skeleton that irrigates every cell of our body. In every poorly functioning organ, as a rule, one finds a spasm of the capillaries, their expansion or contraction. Any pathogenic process is, first of all, a violation of capillary circulation. The heat of the bath increases circulatory processes in the body, relaxes spasms in tissues and organs, which helps restore normal blood circulation, and therefore restores the functioning of an organ or tissue.
The effect of heat on the blood picture. Academician I.R. Tarkhanov proved that after the bath procedure the number of red blood cells and hemoglobin increases. Recent research has confirmed this discovery. Under the influence of the bath procedure, the number of leukocytes - white blood cells involved in the body's immune defense - also increases.
Effect of fever on the heart. Under the influence of the heat of the bath procedure, the work of the heart muscle is activated. The strength of its contractions increases. Regular steam bathing leads to a training effect on the heart muscle. This has been confirmed experimentally. A group of men aged 30-40 years were offered a test to determine the work of the heart muscle - climb to the 12th floor as quickly as possible without an elevator. The time spent on this ascent, heart rate and breathing, as well as the recovery time of these indicators were recorded. Then all participants in the experiment were divided into two groups. One group began jogging twice a week, the other visited the bathhouse the same number of times a week, where contrasting effects were used: four to five visits to the steam room for 5-7 minutes, followed by dousing with cold (12-15 ° C) water in for 20-40 s and 1-2 min warm (35-37 ° C). Between each entry into the steam room, rest for 5-7 minutes. Three months later, the control test was repeated (climbing to the 12th floor without an elevator). Those who jogged and those who took a steam bath showed approximately the same positive changes. All participants in the experiment significantly reduced the time they climbed upward, and at the same time, representatives of both groups showed a more favorable reaction of the cardiovascular and respiratory systems. But what is very important is that the time for recovery of functions decreased sharply, especially for those who visited the bathhouse.
The effect of heat on metabolism. The difficulty of heat transfer by the body causes circulatory activity. Increased blood circulation in turn leads to an increase in body temperature. An increase in temperature affects the increase in the activity of redox enzymes in cells. As a result, oxidative processes are activated in the body. Rapid blood circulation, the release of reserve quantities and an increase in hemoglobin in it allow more oxygen to be delivered to the cells. This in turn stimulates the oxidation processes of substances. This is how the bath procedure increases metabolism by about one third. Nutrients are better absorbed, toxins are oxidized and removed from the body. The activity of enzymes and increased metabolism lead to a person having a healthy appetite. This allows you to normalize many deviations in digestion and increase the absorption of nutrients.
The effect of heat on respiratory function. The sauna perfectly stimulates breathing. Hot, humidified air affects the larynx and the mucous membranes of the nose. Since increased metabolism during fever requires oxygen, breathing becomes faster and deeper, and this in turn improves air exchange in the pulmonary alveoli. Ventilation of the lungs increases by more than two and a half times compared to the indicators before the bath. After the heat of the bath, you breathe better because the pores of the skin are cleaned, toxic contents are removed from the blood, and blood circulation is improved. After a bath procedure, oxygen consumption increases by an average of one third.
The effect of heat on the endocrine glands. Improving blood supply, metabolism and breathing, removing toxins as a result of the bath procedure stimulates the endocrine glands, as a result of which the activity of organs and systems of the body is better regulated and coordinated.
Improving a person's mental state. When the human body improves its functioning as a result of the actions of heat described above, the person feels comfortable. This leads to the fact that the person is now not irritated by anything, and he psychologically rests. In addition, the heat of the bath relieves fatigue, which gradually accumulates towards the end of the week. Lactic acid is removed from the muscles through sweat, which aggravates the feeling of fatigue. The heat of the bath, warming up the skin, muscles, various tissues and organs, causes pleasant relaxation. Relaxation and warming up are the main things necessary for a favorable restoration of vitality. All this creates an inspired, optimistic mood. When the body is relaxed and there is no stiffness, healthy, restful sleep occurs.
Steam room and increased visual acuity. Warmth is one of the functions of the life principle “Bile”, which, in addition to digestion, controls the function of vision. Therefore, it is not surprising that a person’s vision function improves as a result of using a steam room. Scientists in their studies of the bath procedure only confirmed this position of Ayurveda.
Fever and infections. The temperature sensitivity threshold of a number of pathogenic microbes is below the temperature threshold that can be tolerated by the cells of the human body. Therefore, increasing the temperature (sauna, steam room) is widely used to treat a number of infectious diseases.
Based on materials from the book by G.P. Malakhova "Fundamentals of Health"
Sources of the thermal effect of current can be high-frequency currents, metal objects and resistors heated by current, an electric arc, and exposed live parts.
Chemical action.
The human body consists of non-polar and polar molecules, cations and anions. All these elementary particles are in continuous chaotic thermal movement, ensuring the vital functions of the organism. Upon contact with live parts in the human body, instead of a chaotic one, a directed, strictly oriented movement of ions and molecules is formed, disrupting the normal functioning of the body.
Secondary injuries.
A person's reaction to the action of current usually manifests itself in the form of a sharp involuntary movement such as withdrawing the hand from the point of contact with a hot object. With such a movement, mechanical damage to organs is possible due to a fall, impact with nearby objects, etc.
Let's look at different types of electrical damage. Electrical shocks are divided into two groups: electric shock and electrical injuries. Electrical shock is associated with damage to internal organs, while electrical injuries are associated with damage to external organs. In most cases, electrical injuries can be cured, but sometimes, with severe burns, the injuries can lead to death.
The following types of electrical injuries are distinguished: electrical burns, electrical marks, skin metallization, electroophthalmia and mechanical injuries.
Electric shock- this is a damage to the internal organs of a person: excitation of living tissues of the body by an electric current flowing through it, accompanied by involuntary convulsive muscle contractions. The degree of negative impact of these phenomena on the body may vary. In the worst case, an electric shock leads to disruption and even complete cessation of the activity of vital organs - the lungs and heart, i.e. to the death of the organism. In this case, a person may not have external local injuries.
Causes of death due to electric shock may include cardiac arrest, respiratory arrest, and electric shock.
The cessation of heart function, as a result of the effect of current on the heart muscle, is the most dangerous. Cessation of breathing can be caused by direct or reflex effects of current on the chest muscles involved in the breathing process. Electric shock is a kind of severe neuro-reflex reaction of the body to strong irritation by electric current, accompanied by profound disorders of blood circulation, breathing, metabolism, etc.
Small currents only cause discomfort. At currents greater than 10 - 15 mA, a person is unable to independently free himself from live parts and the effect of the current becomes prolonged (non-releasing current). With prolonged exposure to currents of several tens of milliamps and an action time of 15 - 20 seconds, respiratory paralysis and death can occur. Currents of 50 - 80 mA lead to cardiac fibrillation, which consists of random contraction and relaxation of the muscle fibers of the heart, as a result of which blood circulation stops and the heart stops.
Both with respiratory paralysis and with cardiac paralysis, organ functions do not recover on their own; in this case, first aid (artificial respiration and cardiac massage) is necessary. The short-term effect of large currents does not cause either respiratory paralysis or cardiac fibrillation. At the same time, the heart muscle contracts sharply and remains in this state until the current is turned off, after which it continues to work.
The action of a current of 100 mA for 2 - 3 seconds leads to death (lethal current).
Burns occur due to the thermal effects of current passing through the human body, or from touching very hot parts of electrical equipment, as well as from the action of an electric arc. The most severe burns occur from the action of an electric arc in networks of 35 - 220 kV and in networks of 6 - 10 kV with high network capacity. In these networks, burns are the main and most severe types of damage. In networks with voltages up to 1000 V, burns from an electric arc are also possible (when the circuit is disconnected with open switches in the presence of a large inductive load).
Electrical signs- these are skin lesions in places of contact with electrodes of a round or elliptical shape, gray or white-yellow in color with sharply defined edges (D = 5 - 10 mm). They are caused by the mechanical and chemical effects of current. Sometimes they do not appear immediately after the passage of electric current. The signs are painless, there are no inflammatory processes around them. Swelling appears at the site of the lesion. Small marks heal safely, but with large marks, necrosis of the body (usually the hands) often occurs.
Electrometallization of leather- this is the impregnation of the skin with tiny particles of metal due to its splashing and evaporation under the influence of current, for example, when an arc burns. The damaged area of skin acquires a hard, rough surface, and the victim experiences a sensation of the presence of a foreign body at the site of the lesion.
Factors influencing the outcome of electric shock
The impact of current on the human body in terms of the nature and consequences of the damage depends on the following factors:
· electrical resistance of the human body;
· voltage and current values;
· duration of current exposure;
frequency and type of current;
· paths of current passage through the human body;
· state of human health and attention factor;
· environmental conditions.
The amount of current flowing through the human body depends on the touch voltage U pr and the resistance of the human body R h.
Resistance of the human body. The electrical resistance of different parts of the human body is different: the greatest resistance is dry skin, its upper stratum corneum, in which there are no blood vessels, as well as bone tissue; significantly lower resistance of internal tissues; Blood and cerebrospinal fluid have the least resistance. Human resistance depends on external conditions: it decreases with increasing temperature, humidity, and gas pollution in the room. Resistance depends on the condition of the skin: in the presence of damaged skin - abrasions, scratches - the resistance of the body decreases.
So, the upper stratum corneum of the skin has the greatest resistance:
· with the stratum corneum removed;
· for dry, undamaged skin;
· with moisturized skin.
The resistance of the human body also depends on the magnitude of the current and the applied voltage; on the duration of current flow. contact density, contact area with live surfaces and electric current path
To analyze injuries, the resistance of human skin is taken. As the current passing through a person increases, its resistance decreases, because at the same time the heating of the skin increases and sweating increases. For the same reason, R h decreases with increasing duration of current flow. The higher the applied voltage, the greater the human current Ih, the faster the human skin resistance decreases.
The magnitude of the current.
Depending on its magnitude, an electric current passing through a person (at a frequency of 50 Hz) causes the following injuries:
· at 0.6 -1.5 mA - slight hand trembling;
· at 5 -7 mA - cramps in the hands;
· at 8 - 10 mA - cramps and severe pain in the fingers and hands;
· at 20 - 25 mA - paralysis of the arms, difficulty breathing;
· at 50 - 80 mA - respiratory paralysis, with a duration of more than 3 s - cardiac paralysis;
· at 3000 mA and for a duration of more than 0.1 s - respiratory and cardiac paralysis, destruction of body tissue.
The voltage applied to the human body also affects the outcome of the injury, but only insofar as it determines the value of the current passing through the person.
Prevention:
Pay attention to the ergonomic design of the workplace.
1. Place the monitor so that its top point is directly in front of your eyes or higher, which will allow you to keep your head straight and prevent the development of cervical osteochondrosis. The distance from the monitor to the eyes should be at least 45 cm;
2. The chair must have a back and armrests, as well as a height at which the legs can rest firmly on the floor. It would be ideal to purchase a chair with adjustable height, in which case the backrest will allow you to keep your back straight, the armrests will give you the opportunity to rest your arms, and the correct position of your legs will not interfere with blood circulation in them;
3. The location of frequently used items should not lead to a long stay in any twisted position;
4. Workplace lighting should not cause glare on the monitor screen. You cannot place the monitor next to a window so that you can simultaneously see both the screen and what is outside the window.
5. When working with the keyboard, the bend angle of the arm at the elbow should be straight (90 degrees);
6. When working with the mouse, the hand should be straight and lie on the table as far from the edge as possible. While working, do not forget about regular breaks for rest. Limit the amount of time.
1. Ionizing radiation as an unfavorable environmental factor Natural background radiation, its magnitude and components. Hygienic significance of radon.
Guiding documents.
Guiding documents.
1. Federal Law on Radiation Safety No. 3-FZ
2. Radiation safety standards (NRB 99) SP 2.6.1.758-99
3. Basic joint ventures for ensuring radiation safety.
4. Hygiene requirements for the design and operation of X-ray rooms, devices and the conduct of X-ray examinations. SanPiN 2.6.1.802-99
Radiation hygiene is a branch of hygienic science that studies the impact of AI on human health and develops measures to reduce its adverse effects.
Radiation safety of the population is the state of protection of the present and future generations of people from the harmful effects of AI on their health.
II is radiation that is created during radioactive decay, nuclear transformations, inhibition of charged particles in matter, and forms ions of different signs when interacting with the environment. A measure of sensitivity to the action of AI is radiosensitivity.
AI can be corpuscular (alpha, beta particles, cosmic rays, protons, neutrons) and electromagnetic (gamma, x-rays). Alpha radiation is AI consisting of alpha particles (helium nuclei - 2 protons and 2 neutrons), emitted during nuclear transformations .Beta radiation is electron and positron radiation emitted during nuclear transformations. Gamma radiation - photon
AI is divided into two groups:
1Closed radiation sources, the design of which excludes environmental pollution by radioactive substances under foreseeable conditions of their use, but in case of violation of the recommended technology or an accident they can still enter the environment. Closed sources of radiation include: gamma installations, X-ray machines, ampoules with radioactive substances, metal cartridges with radioactive substances fused into the metal of the radioactive substance.
2Open - radiation sources, the use of which may result in radioactive substances entering the external environment and contaminating it. Open sources of radiation include radioactive substances in powder, dissolved or gaseous states, used after depressurization of the packaging. Objects working only with closed AI can be located inside residential areas without establishing sanitary protection zones, provided that the necessary protective fences are in place. When working with sealed sources, the greatest danger is external irradiation, i.e. irradiation of the body from radiation sources located outside it. AI with a long range is dangerous here, i.e. with high penetrating power (X-ray, gamma radiation).
Radiation exposure of the population in modern conditions, including the contribution of medical procedures using research institutes. radiation risk, methods for its assessment.
2. Food poisoning of non-microbial etiology. The reasons for their occurrence. Main directions of warning.
Food poisoning includes diseases of various natures that occur when eating food containing pathogens or their toxins or other substances of a non-microbial nature that are toxic to the body.
NON-MICROBIAL FOOD POISONING
This group includes poisoning by inedible poisonous products (mushrooms and wild plants), food products that have temporarily become poisonous or partially acquired toxic properties (potato solanine, beans, bitter kernels of stone fruits, animal organs), poisoning caused by toxic impurities in food products (salts of heavy metals, weeds and pesticides).
Poisoning by inedible products of plant and animal origin Mushroom poisoning. Among plant poisonings, the most common are diseases caused by fungi. On average, about 15% of cases of mushroom poisoning are fatal.
Prevention: mandatory boiling of mushrooms, do not use decoction. Poisoning is also possible when eating edible mushrooms if they are contaminated with microorganisms and are stored for a long time. Mushrooms can also be contaminated with chemical compounds (from soil, dishes). Prevention requires knowledge of mushroom preparation technology. Prevention: limiting the list of mushrooms allowed for procurement and sale; admission to the procurement and sale of only mushrooms sorted by individual types; limiting the types of mushrooms allowed for sale in dried form; Sanitary education work with the population.
Stone fruit kernels (apricots, peaches, plums, cherries, cherries, dogwoods, bitter almonds). The kernels of these plants constantly contain the glycoside amidalin, which, when broken down, releases hydrocyanic acid. Prevention: health education, work explaining possible serious complications, monitoring of children.
Mycotoxicoses. Diseases resulting from consumption of food products in which toxic fungi have multiplied.
Ergotism is poisoning by ergot horns that affect rye and, less commonly, wheat. Prevention: monitoring the toxin content in flour, carrying out agrotechnical measures.
Alimentary-toxic aleukia - occurs when consuming products made from cereal grains that have overwintered under the snow while standing. Dyspeptic symptoms are characteristic, followed by leukopenia and various sore throats, incl. necrotic. Prevention: prohibition of eating overwintered grain.
Aflatoxicoses. After a short incubation period (up to 2 days), the phenomena of neurotoxicosis (impaired coordination of movements, convulsions, paresis), hemorrhagic syndrome and progressive cirrhosis of the liver (the most powerful carcinogen) develop. Prevention: Control of mold in products.
Food poisoning by pesticides. Pesticides (pesticides) are synthetic chemicals of varying degrees of toxicity used in agriculture to protect cultivated plants from weeds, pests and diseases, as well as to stimulate growth, development of fruit seeds and other purposes. Prevention: complete elimination of residual pesticides in the external environment and those with a pronounced cumulative effect; residual amounts of those substances that do not have a harmful effect are allowed; strict compliance with the instructions for use (purpose, concentration, type of treatment, timing); content control.
3. Social and hygienic significance of housing. Hygienic requirements for the layout, equipment and maintenance of residential buildings and apartment-type premises.
SanPiN 2.1.2.1002-00 (as amended on August 21, 2007 N59)
Requirements for residential buildings and public premises located in residential buildings:
1. The construction of residential buildings must be carried out according to designs that meet the requirements of these rules.
3. The height of residential premises from floor to ceiling in social housing buildings must be at least 2.5 m.
4. Placement of public facilities that have a harmful effect on humans is not allowed in residential buildings.
5. Public premises built into residential buildings must have entrances isolated from the residential part of the building.
6. When placing public premises, engineering equipment and communications in a residential building, compliance with hygienic standards, including noise protection of residential premises, should be ensured.
Requirements for the maintenance of residential premises
1. It is not allowed:
Use of residential premises for purposes not provided for in the design documentation;
Storage and use in residential premises and public premises located in a residential building of substances and objects that pollute the air;
Carrying out work or performing other actions that are sources of increased levels of noise, vibration, air pollution, or disrupt the living conditions of citizens in neighboring residential premises;
Littering, pollution and flooding of basements and technical underground areas, stairwells and cages, attics, and other common areas;
Use of household gas appliances for space heating.
2. Required:
Timely take measures to eliminate malfunctions of engineering and other equipment located in residential premises (water supply, sewerage, ventilation, heating, waste disposal, elevator systems, etc.) that violate sanitary and hygienic conditions;
Ensure timely removal of household waste, maintain garbage chutes and garbage collection chambers in good condition;
Carry out measures aimed at preventing the occurrence and spread of infectious diseases associated with the sanitary condition of a residential building. If necessary, carry out measures to destroy insects and rodents (disinsection and deratization).
1. Soil Its hygienic and epidemiological significance. Composition and properties Sources of anthropogenic pollution. Criteria for assessing sanitary condition. Self-cleaning processes.
Soil refers to the top layer of the Earth's surface, consisting of mineral and organic substances, populated by a large number of microorganisms.
Chemical composition of the soil.
Healthy soil is soil that is easily permeable, coarse-grained, and uncontaminated. The soil is considered healthy if the content of clay and sand in it is 1:3, there are no pathogens or helminth eggs, and microelements are contained in quantities that do not cause endemic diseases.
The physical properties of soil include:
1Porosity(depends on the size and shape of the grains)
2 Soil capillarity. The ability of soil to raise moisture.
3 Soil moisture capacity- that is, the ability of the soil to retain moisture: chernozem will have high humidity, podzolic soil will have less moisture, and sandy soil will have even less moisture.
4 Soil hygroscopicity- this is the ability to attract water vapor from the air.
5 Soil air.
Clean soil contains mainly oxygen and carbon dioxide; contaminated soils contain hydrogen and methane.
6 Soil moisture- exists in chemically bound, liquid and gaseous states. Soil moisture influences the microclimate and the survival of microorganisms in the soil.
Epidemiological significance.
Causative agents of infectious diseases - they are divided into 2 groups:
1.Permanently living in the soil. These include pathogens that cause gas gangrene, anthrax, tetanus, botulism, and actinomycosis.
2. Microorganisms temporarily present in the soil are pathogens of intestinal infections, pathogens of typhoid-parotiphoid diseases, dysentery bacteria, Vibrio cholerae; The causative agents of tuberculosis and the causative agents of tularemia can be present in the soil both permanently and temporarily.
Hygienic importance of soil
The soil has a great ability to inactivate harmful substances and pathogenic microorganisms that enter it due to physicochemical processes, microbiological decomposition, absorption by higher plants and soil fauna, i.e., it actively participates in self-purification processes.
Classification of soil pollutants:
Soil pollution- a type of anthropogenic soil degradation in which the content of chemicals in soils subject to anthropogenic impact exceeds the natural regional background level of their content in soils.
1) Garbage, emissions, dumps, sludge.
2) Heavy metals.
3) Pesticides.
4) Mycotoxins.
5) Radioactive substances.
Criteria for assessing sanitary conditions:
1. Sanitary and chemical criteria. For sanitary and hygienic assessment of soil, it is also important to know the content of such pollution indicators as nitrites, ammonia salts, nitates, chlorides, sulfates. Their concentration or dose should be compared with control soil for the area. The soil air is assessed for its hydrogen and methane content, along with carbon dioxide and oxygen.2. Sanitary and bacteriological indicators: these include titers of microorganisms. 3. Helminthological assessment. Clean soil should not contain helminths, their eggs and larvae. 4. Sanitary and entomological indicators - count the number of larvae and pupae of flies. 5. Algological indicators: yellow-green algae predominate in clean soil, blue-green and red algae - in contaminated soil .6.Radiological indicators: it is necessary to know the level of radiation and the content of radioactive elements. 7.Biogeochemical indicators (for chemicals and trace elements).
Soil self-purification- the ability of the soil to reduce the concentration of a pollutant as a result of migration processes occurring in the soil.
Under the action of the enzymes of putrefactive bacteria, complex organic substances that have entered the soil are decomposed into simple mineral compounds (CO2, H2O, NH3, H2S), available for the nutrition of autotrophic organisms. Along with the processes of decomposition of organic substances, synthesis processes occur in the soil.
2. Sanitary and epidemiological requirements for the storage and primary processing of food products, preparation and storage of prepared food.
Products are processed in appropriate production facilities using separate cutting boards and knives labeled for each product.
When storing food products in industrial warehouses, attention is paid to the terms and conditions of storage, especially temperature conditions. Food is delivered to the canteen for each meal, taking into account the time required for its technological processing (frozen meat 12 hours in advance, frozen fish 4-6 hours in advance). Frozen meat is thawed uncut, hanging on hooks (in water is prohibited) before cutting. carcasses are washed with water, contaminated areas, marks, bruises are cut off.
It is important to strictly adhere to the time flow of food processing. The lead time for preparing dishes from the completion of primary processing of raw materials and semi-finished products to heat treatment and sale of finished food should be minimal. The minced meat is prepared no earlier than an hour before cooking. Storage of the semi-finished product is allowed only in the refrigerator. Frozen fish is left to stand in cold water for 2-4 hours, fillets - on production tables at room temperature. Thawed fish is immediately subjected to primary and then heat treatment.
Heat treatment: meat is cooked in pieces of 1.5-2 kg for 2-2.5 hours.
Milk received in tanks can only be used after boiling.
Peeled potatoes can be stored for no more than 4 hours
Before serving, meat portions must be subjected to repeated heat treatment (boiling in broth for 15-20 minutes)
Preparation of sweet dishes should be completed no earlier than 2 hours before meals.
Ready food is served on the tables 10-15 minutes before meal time. The temperature of the food at the time of its consumption should be no lower than 75 degrees for first courses, no lower than 65 degrees for second courses, no lower than 65 degrees for tea, no higher than 14 degrees for cold appetizers.
The shelf life of food in the refrigerator should not exceed 4 hours.
Before delivery, food undergoes mandatory repeated heat treatment. The first courses are boiled, the meat portions are boiled for 15-20 minutes, the fish portions and side dishes are fried. Their further storage after heat treatment is not permitted.
3. Factors contributing to hypothermia of the human body. Main directions and means of prevention.
Temperature below +15°C is considered low. A temperature that does not cause stress on the thermoregulatory apparatus, when the balance between heat production and heat transfer is maintained, is considered optimal (thermal comfort).
When air temperature drops below optimal values (especially in combination with wind and high air humidity), heat loss from the body increases. For some time (depending on the body’s training), this is compensated by thermoregulatory mechanisms.
With a significant increase in the cooling capacity of the environment, the thermal balance is disrupted: heat loss exceeds heat production, and hypothermia occurs in the body.
First of all, superficial tissues (skin, fatty tissue, muscles) are cooled, while maintaining the normal temperature of parenchymal organs. This is not dangerous and helps reduce heat loss.
With further cooling, the temperature of the whole body decreases, which is accompanied by a number of negative phenomena (the body's resistance to infections decreases).
With local cooling of individual parts of the body, diseases of the musculoskeletal system (myositis, arthritis) and the peripheral nervous system (neuritis, radiculitis) can develop.
Prevention: 1 – Hardening – training the body, increasing its resistance to cooling. 2 – Selection of appropriate clothing. 3 – Creation of a favorable indoor microclimate (heating). 4 – More high-calorie food.
1. Risk factors for the health of schoolchildren in general education institutions.
The content and organization of training should always correspond to the age characteristics of students. Selection of the volume of the educational load and the level of complexity of the material being studied in accordance with the individual capabilities of the student is one of the main and mandatory requirements for any educational technology, which determines the nature of its impact on the student’s health. However, it is very difficult to do this in a mass modern school.
A significant increase in the workload at school: children have a high prevalence of neuropsychiatric disorders, fatigue, accompanied by immune and hormonal dysfunctions. Overwork creates the preconditions for the development of acute and chronic health problems, the development of nervous, psychosomatic and other diseases. There is a tendency towards an increase in the number of diseases of the nervous system and sensory organs in children.
Forced body position during work, “monotonia”.
Early start of lessons in the 1st shift, and late end of lessons in the 2nd shift.
2. Exhaust gases from internal combustion engines. Their composition, effect on the human body and prevention of poisoning.
Exhaust gas is a mixture of gases with an admixture of suspended particles formed as a result of the combustion of motor fuel.
The components contained in exhaust gases can be divided into harmful and harmless.
Harmless:
Oxygen O2
Carbon dioxide CO2 see later greenhouse effect
Water vapor H2O
Harmful substances:
Carbon monoxide CO (carbon monoxide)
Hydrocarbon compounds HC (unburned fuel and oil)
Nitrogen oxides NO and NO2 which are designated NOx because O is constantly changing
Sulfur oxide SO2
Particulate matter (soot)
The quantity and composition of exhaust gases are determined by the design features of the engines, their operating mode, technical condition, quality of road surfaces, and weather conditions.
The toxic effect of CO lies in its ability to convert part of the hemoglobin in the blood into carboxyhemoglobin, which causes disruption of tissue respiration. Along with this, CO has a direct effect on tissue biochemical processes, leading to disruption of fat and carbohydrate metabolism, vitamin balance, etc. The toxic effect of CO is also associated with its direct effect on the cells of the central nervous system. When exposed to humans, CO causes headache, dizziness, fatigue, irritability, drowsiness, and pain in the heart area. Acute poisoning occurs when air with a CO concentration of more than 2.5 mg/l is inhaled for 1 hour.
Nitrogen oxides irritate the mucous membranes of the eyes, nose, and mouth. Exposure to NO2 contributes to the development of lung diseases. Symptoms of poisoning appear only after 6 hours in the form of coughing, choking, and increasing pulmonary edema is possible. NOx are also involved in the formation of acid rain.
Certain CH hydrocarbons (benzapyrene) are the strongest carcinogenic substances, the carriers of which can be soot particles.
When an engine runs on leaded gasoline, particles of solid lead oxide are formed. The presence of lead in the air causes serious damage to the digestive organs, central and peripheral nervous systems. The effect of lead on the blood is manifested in a decrease in the amount of hemoglobin and the destruction of red blood cells.
Prevention:
Alternative fuels.
Legislative restrictions on emissions of harmful substances
Exhaust gas aftertreatment system (thermic, catalytic)
3. Organization of meals for military personnel in stationary conditions. Types of food. Main directions and content of medical control.
Proper organization of military nutrition is achieved by fulfilling the following requirements:
· constant monitoring of the completeness of delivery of the required food rations to those who eat;
· proper planning of nutrition for personnel, rational use of food rations, mandatory compliance with culinary rules for food processing and preparation, development and observance of the most appropriate diet for various contingents of military personnel, taking into account the nature and characteristics of their official activities;
· preparing tasty, nutritious, high-quality and varied food according to established food ration standards;
· arrangement and equipment of canteens for military units, taking into account the introduction of advanced technologies and the creation of maximum convenience in work;
· skillful operation of technological, refrigeration and non-mechanical equipment, tableware and kitchen utensils, their timely maintenance and repair;
· compliance with sanitary and hygienic requirements when processing food, preparing, distributing and storing food, washing dishes, maintaining the dining room premises, as well as personal hygiene rules for cooks and other canteen workers;
· clear organization of the work of the cook staff and daily work at the canteen of the military unit;
· observance by military personnel of the standards of behavior determined by the Charter in the canteen during meals;
· holding events aimed at improving and improving the organization of military nutrition: nutrition conferences, competitions for the best canteen, food exhibitions, etc.;
·regularly conducting control tests, cooking, classes with junior food service specialists and improving their qualifications.
The nutritional regimen of military personnel determines the number of meals during the day, the observance of physiologically justified time intervals between them, the appropriate distribution of foods among meals, prescribed according to food rations during the day, as well as meals at times strictly established by the daily routine.
The development of a nutritional regimen for military personnel is entrusted to the commander of the military unit, his deputy for logistics, and the heads of the food and medical services of the military unit.
Depending on the nature of combat training activities and food ration standards, three or four meals a day are established for personnel of the RF Armed Forces.
Three meals a day (breakfast, lunch and dinner) are organized in a military unit, where personnel eat a general ration and at least 4 times a ration for Suvorov, Nakhimov and military music school students.
The intervals between meals should not exceed 7 hours. Taking this into account, when establishing the daily routine of a military unit, breakfast is planned before the start of classes, lunch - after the end of main classes, dinner - 2-3 hours before lights out. After lunch for 30 minutes. (not less) it is not allowed to conduct classes or work.
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