WORKING ENVIRONMENT MICROCLIMATE

Microclimate industrial premises is determined by the combinations of temperature, humidity and air velocity acting on the human body, as well as the temperature of the surrounding surfaces (GOST 12.1.005-88).

If the work is carried out in open areas, then the meteorological conditions are determined by the climatic zone and the season of the year, but even in this case, a certain microclimate is created in the working area.

With favorable combinations of microclimate parameters, a person whose life condition is to preserve constant body temperature experiences a state of thermal comfort - an important condition for high labor productivity and disease prevention.

Adverse meteorological conditions environment

Unfavorable meteorological environmental conditions arise when the combinations of temperature, humidity, and air velocity that affect a person deviate from the optimal ones. A significant deviation of the microclimate of the working area from the optimal one can lead to a sharp decrease in working capacity and even to occupational diseases.

Overheat. At an air temperature of more than 30 ° C and significant thermal radiation from heated surfaces, a violation of the body's thermoregulation occurs, which can lead to overheating of the body, especially if the sweat loss per shift approaches 5 liters. There is increasing weakness, headache, tinnitus, distortion of color perception, nausea, vomiting, body temperature rises. Respiration and pulse quicken, blood pressure first rises, then falls. In severe cases, heat stroke occurs, and when working outdoors, sunstroke. A convulsive illness is possible, which is a consequence of a violation of the water-salt balance and is characterized by weakness, headache, and severe convulsions.

Cooling. Prolonged and strong exposure to low temperatures can cause various adverse changes in the body.

the lowness of man. Local and general cooling of the body is the cause of many diseases: myositis, neuritis, radiculitis, etc., as well as colds. In severe cases, exposure to freezing temperatures can lead to frostbite and even death.

Humidity air is determined by the content of water vapor in it, there are:

- absolute(L) is the mass of water vapor contained in
a given moment in a certain volume of air;

- maximum(A () - the maximum possible content in
dynyh vapors in the air at a given temperature (saturation state);

- relative (B)- is determined by the ratio of the absolute
humidity A to maximum M and expressed as a percentage:

B = (A/M) 100%.

Physiologically optimal is relative humidity in the range of 40...60%. Increased air humidity (more than 75...85%) in combination with low temperatures has a significant cooling effect, and in combination with high temperatures, it contributes to overheating of the body. Relative humidity less than 25% is also unfavorable for humans, as it leads to drying of the mucous membranes and a decrease in the protective activity of the ciliated epithelium of the upper respiratory tract.

Air mobility. A person begins to feel the movement of air at its speed of approximately 0.1 m / s. A slight movement of air at ordinary temperatures contributes to good health, blowing off the superheated layer of air that envelops a person, saturated with water vapor. At the same time, the high speed of air movement, especially at low temperatures, causes an increase in heat loss by convection and evaporation and leads to a strong cooling of the body. Strong air movement is especially unfavorable when working outdoors in winter conditions.

thermal radiation characteristic of any body whose temperature is above absolute zero. The thermal effect of irradiation on the human body depends on the wavelength and intensity of the radiation flux, the size of the irradiated area of ​​the body, the duration of irradiation, the angle of incidence of the rays, and the type of human clothing. Infra-red rays with a wavelength of 0.78 ... 1.4 microns have the greatest penetrating power; they also cause various biochemical and functional changes in the human body.

Sources of thermal radiation- working technological equipment, light sources, working people. The intensity of irradiation of workers in hot shops varies widely: from a few tenths to 5.0...7.0 kW/m 2 . At the intensity of irradiation

values ​​of more than 5.0 kW / m 2 for 2 ... 5 minutes, a person feels a strong thermal effect. The intensity of thermal radiation at a distance of 1 m from the heat source in the hearth areas of blast furnaces and open-hearth furnaces with open dampers reaches 11.6 kW/m 2 .

The permissible level of intensity of thermal exposure for a person at workplaces is 0.35 kW / m 2 (GOST 12.4.123-83 SSBT "Means collective defense from infrared radiation. General technical requirements").

One of necessary conditions normal human life is to ensure normal meteorological conditions in the premises, which have a significant impact on the thermal well-being of a person. Meteorological conditions, or microclimate, depend on the thermophysical features of the technological process, climate, season, ventilation and heating conditions.

Normal thermal well-being takes place when the heat release of a person is completely perceived by the environment. If the body's heat production cannot be fully transferred to the environment, the temperature of the internal organs rises and such a thermal well-being is characterized by the concept of hot. IN otherwise- Cold.

Heat exchange between a person and the environment is carried out by convection as a result of washing the body with air, thermal conductivity, radiation to surrounding objects and in the process of heat and mass transfer during the evaporation of moisture, which is removed to the surface of the skin by sweat glands and during breathing.

That is, the thermal well-being of a person, or the thermal balance in the human-environment system, depends on the temperature of the environment, the mobility and relative humidity of the air, atmospheric pressure, the temperature of surrounding objects and the intensity of physical activity.

The parameters - temperature, air velocity, relative humidity and atmospheric pressure of the surrounding air - are called microclimate parameters.

The parameters of the microclimate have a direct impact on the thermal state of a person. For example, a decrease in temperature and an increase in the speed of air movement contribute to an increase in convective heat transfer and the process of heat transfer during the evaporation of sweat, which can lead to hypothermia of the body. An increase in the speed of air movement worsens health, as it contributes to an increase in convective heat transfer and the process of heat transfer during sweat evaporation.

With profuse perspiration, the mass of the human body decreases. It is considered acceptable for a person to reduce his weight by 2 ... 3% by evaporation of moisture - dehydration of the body.

Prolonged exposure to high temperatures, especially with high humidity, can lead to a significant accumulation of heat in the body and the development of overheating of the body above acceptable level- hyperthermia.

Production processes performed at low temperatures, high air mobility and humidity can cause cooling and even hypothermia of the body - hypothermia.

According to the nature of the impact on the human body, infrared rays are divided into short-wave and long-wave. Thermal radiation of the short-wave range penetrates deeply into the tissues and heats them up, causing rapid fatigue, decreased attention, increased sweating, and with prolonged exposure - heat stroke. Long-wave rays do not penetrate deep into the tissues and are absorbed mainly in the epidermis of the skin. They can cause burns to the skin and eyes (cataracts of the eye). Belov S.V., Ilnitskaya A.V., Kozyakov A.F. Life safety. Textbook for universities - Moscow, publishing house "Higher School", 2004. - p.71

The main parameters that ensure the process of heat exchange with the environment are the parameters of the microclimate. Under natural conditions, these parameters vary within significant limits.

Along with the change in the parameters of the microclimate, the thermal well-being of a person also changes. Conditions that violate the heat balance cause reactions in the body that contribute to its restoration. The processes of regulating heat release to maintain a constant temperature of the human body are called thermoregulation. It allows you to keep the temperature of the internal organs constant, close to 36.5 ° C.

The processes of regulation of heat release are carried out mainly in three ways: biochemically, by changing the intensity of blood circulation and the intensity of perspiration.

The parameters of the microclimate of the air environment, which determine the optimal metabolism in the body and in which there are no unpleasant sensations and tension in the thermoregulation system, are called comfortable or optimal. The zone in which the environment completely removes the heat generated by the body, and there is no tension in the thermoregulation system, is called the comfort zone. Conditions under which the normal thermal state of a person is violated are called uncomfortable. With a slight tension in the thermoregulation system and slight discomfort, acceptable meteorological conditions are established. Belov S.V., Ilnitskaya A.V., Kozyakov A.F. Life safety. Textbook for universities - Moscow, publishing house "Higher School", 2004. - p.73

Department of Life Safety

LECTURE

FOR SECURITY

vital activity

Subsystem "Environment" as an element

systems "Man-machine-environment"

Chelyabinsk 2008

1. Characteristics of the meteorological conditions of the environment….……….…………3

2. Characteristics of industrial lighting…………………………..4

3. Characteristics of chemical and biological hazardous and harmful production factors of the environment ...………………………………………………… 7

4. Characteristics of ionizing and electromagnetic dangerous and harmful production factors of the environment……………………………………..13

5. Assessment of the security level of the state of the subsystem "Environment"………16

6. Systems and means of ensuring regulatory parameters of meteorological conditions and the composition of the air and the environment ....................................................................................................................................................

7. Systems, methods and means of cleaning Wastewater and sludge treatment…………………………………………………………………………………..21

Characteristics of the meteorological conditions of the environment

Wednesday can be conditionally divided into industrial and household (regulated) and environmental (unregulated).

Meteorological conditions of the production and household environment- characterized by a combination of temperature parameters, relative humidity and air velocity, ambient surface temperature and barometric pressure.

Meteorological environmental conditions- characterized by a combination of temperature, relative humidity, air velocity and degree of vertical stability, thermal radiation and barometric pressure.

Meteorological conditions of the environment can be estimated by the thermal state of a person, which is characterized by its heat content. At the same time, the heat content of a person at rest is 4 ... 6 kJ / min, and during hard work - 36 ... 42 kJ / min.

At air temperature within 15 ... 25 ° C a person experiences a state of thermal indifference, and his heat exchange with the environment occurs due to convection (25 ... 30%), thermal radiation (45%) and evaporation (20 ... 25%).

At an air temperature of about 30 o C heat exchange between a person and the environment occurs due to convection and thermal radiation (50%) and evaporation (50%).

At an air temperature of about 36 ° C heat exchange between a person and the environment occurs only due to evaporation (100%).

The combination of parameters of meteorological conditions can create an improvement or deterioration in the thermal state of a person.

The influence of temperature and relative humidity parameters on the thermal state of a person is characterized by equivalent temperature , and taking into account the additional air velocity - equivalent effective temperature. The influence of the whole complex of parameters of meteorological conditions on the thermal state of a person can be assessed by the criterion of thermal comfort, in particular, by the person's heat sensations.

degree of vertical air stability characterized by the state of the atmosphere in the surface layer of air (inversion, convection, isotherm).

Inversion It is created when the air temperature of the lower layer is lower than the air temperature of the upper layer, usually occurs in clear weather with a wind speed of more than 4 m / s, one hour before sunset, one hour after sunrise.

Convection It is created under the condition that the air temperature of the lower layer is higher than the air temperature of the upper layer, usually occurs in clear weather with a wind speed of no more than 4 m / s, two hours after sunrise and two, two and a half hours before sunset.

Isotherm- is created under the condition that, within 20 ... 25 m from the earth's surface, the air temperature of the lower and upper air layers is practically equal, usually occurs in cloudy weather and with snow cover.

Principles of normalization of parametersmeteorological conditions of the production and household environment differentiated depending on the thermal characteristics of the room, season And categories of work by severity .

According to the thermal characteristic, the premises are divided into premises with a low excess of sensible heat.<23 Дж/м 3 ·с и значительным >23 J / m 3 s.

Meteorological conditions (microclimate)

Under them is meant a set of factors of atmospheric phenomena: temperature, humidity, air mobility, atmospheric pressure. This also includes infrared radiation (heat), ultraviolet (solar) radiation, geomagnetic field, air ionization. In hygienic terms, meteorological conditions are a complex of physical environmental factors that affect the body's heat exchange and its thermal state.

Meteorological conditions are mainly determined by climate and weather. Climate is a long-term stable weather condition that is characteristic of a given area, due to its geographical location. The climate can be cold, temperate and hot. Weather is a temporary state of meteorological conditions, which is determined in a given area and in a given place. The weather can be sunny, rainy, dry, cloudy, etc.

Hygienic value of climate. The climate, being the most important component of the natural environment, affects the nature economic activity person, his way of life, living conditions, health, structure and level of morbidity. The distribution of various pathogens and their carriers depends on the climate, which is associated with the geographical distribution of many diseases. Therefore, climatic conditions are taken into account in hygienic recommendations for civil (residential buildings, hospitals, sanatoriums, etc.) and industrial construction, ensuring rational nutrition, clothing, footwear, working and living conditions, preventing the occurrence and exacerbation of various diseases.

The most important climate-forming factors in a particular area are geographical latitude, height above sea level, relief and type of the earth's surface, features of the circulation of air masses, proximity to the seas and oceans. Recently, a certain influence on climatic conditions has been exerted by a variety of human production activities.

Indicators characterizing climate reflect long-term processes, therefore they are average statistical data characterizing temperature, air humidity, precipitation, atmospheric pressure, wind rose and their speed, amount of solar radiation, clear and cloudy days, light climate, duration of winter, the depth of soil freezing over a long period. Depending on the main climatological indicators and taking into account geographical location There are seven main climatic zones in the world.

There are several types of climate classifications. For construction works it is convenient to classify the territory of the country on the basis of average temperatures in January and July, highlighting four climatic regions: 1 - cold, 11 - moderate, 111 - warm, IV - hot. This classification is taken into account when deciding on the planning and development of populated areas, the orientation of buildings, the thickness of the walls, the calculation of heating, the size of window openings, the depth of water pipes, landscaping, etc.

In medical practice, the division of climate into gentle and annoying is used. A warm climate with small temperature amplitudes, with relatively small annual, monthly and daily fluctuations of other meteorological factors, is considered to be gentle. Sparing, i.e. one that presents minimum requirements to adaptive physiological mechanisms, is the forest climate of the middle zone.

The irritating climate is characterized by a significant daily and seasonal fluctuation of meteorological factors, therefore, it imposes increased requirements on the mechanisms and devices used. Irritating is the cold climate of the North, the alpine and hot climate of the steppes of the country.

Various combinations of components of meteorological conditions may have Negative consequences in well-being and the occurrence of certain diseases in humans, which are called meteopathic.

Hot windless weather with high air humidity causes tension in thermoregulatory mechanisms, so physiological changes in the body can lead to overheating of the body. Low temperatures, high air humidity and strong winds can lead to cooling of the body and contribute to an increase in the incidence of pulmonary diseases, tonsillitis, inflammatory diseases kidneys, etc. When a combination of components of meteorological factors leading to intense hypothermia (severe frost with wind or relatively low air temperature and dampness), frostbite may occur, and the combination of low temperature with dampness leads to frostbite of the lower extremities ("Trench foot").

Weather conditions matter in distribution infectious diseases. For example, on hot days, conditions are created that favor the occurrence of food poisoning of microorganism origin.

One of the most important features of meteorological conditions should be considered their instability, constant variability, independent of the will of man. In these cases, the majority of healthy people with well-developed physiological adaptive mechanisms do not notice changes in their state of health or condition associated with weather changes. Such people are called weather resistant or weather stable. However, there are people who are sensitive to weather changes. These are the so-called weather-labile, or weather-sensitive people. For most of these people, adverse weather causes deterioration. general well-being, sleep disturbance, anxiety, dizziness, decreased performance, fatigue. Arterial pressure changes sharply, pain is felt in the region of the heart, sensitivity to drugs often decreases.

It has been proven that unfavorable weather adversely affects the course of many diseases of the cardiovascular system, respiratory organs, endocrine system, digestive tract, skin, eye, neuropsychiatric diseases. There is evidence of an increase in the number of cases of miscarriage, street and other types of injuries, car accidents, murders, and suicides due to adverse weather.

Unfavorable temperature conditions (high or very low temperature) worsen working conditions in open areas, for example, construction workers, assemblers, lumberjacks, agricultural workers.

The reactions of the body in response to the impact of the microclimate are diverse in their manifestation. But all of them are characterized by a common feature - they occur simultaneously in many people who are united only by the meteorological situation. At the same time, a more pronounced reaction is observed when people's adaptive resources are reduced, for example, due to seasonal fluctuations in the ultraviolet or vitamin supply of the body, malnutrition, overwork, and various diseases.

Currently, criteria for medical weather forecasting are being developed, which are expressed in predicting the effect of the expected weather on a person in order to prevent possible negative reactions of the body. One of these indicators is the weather instability index.

where a is the number of days with weather changes; b is the total number of days in the observed period (season, year).

Index K> 0.5 is regarded as unfavorable.

Hygienic value industrial microclimate.

The production microclimate is that set of parts of meteorological conditions that can be in a given enterprise, in a given production at a given workplace.

An objective assessment of a person's thermal well-being is more complex and responsible. For this purpose, a calculation method for determining the thermal value based on a comparison of the values ​​of heat production and heat transfer under assumed or real conditions can be used. With regard to the subjective gradation of a person's heat sensations, objective indicators of his thermal state are given in Table. 5.2.

The thermal state of a person and its quantitative values ​​are characterized by the ratio of heat production values ​​of heat transfer, which determines the state of heat balance, the physiological significance of thermal homeostasis lies in the fact that human life is accompanied by heat. Even at rest, an adult is 3.34-6.27 kJ per 1 kg of body weight per hour, which for a day with a body of 60 kg will be approximately 4.81 60 24 = tJ926 kJ.

A very important condition for maintaining physiological thermal homeostasis is adequate heat transfer to the environment by radiation, conduction (convection), contact and soaring from the body surface, which make up 85-90% of the entire heat transfer. IN comfortable conditions heat transfer by radiation is 40-45%, by conduction - 30-40%, by evaporation 10-15%.

The total heat loss (Qtotal, kJ/h) of a person in these microclimatic conditions is calculated by the formula

Qsum \u003d QP + Qc + Qsp,

where QP - heat transfer by radiation;

Qk - heat transfer by convection;

Qsp - heat transfer by evaporation.

Heat losses are calculated in various ways using special formulas. The simplified basic formula for calculating such heat losses has the following expression:

Q = K(tlFJ - t2f2)SCFBVB,

where Q is heat transfer in one way or another, kJ / h; K - thermal coefficient; tl - average body temperature, oc; (2 - average temperature from the heater, or room air temperature, °C; F1 - maximum humidity at average body temperature, GPa; F2 - absolute humidity at a given room air temperature (F1 and F2 are used instead of t1 and t2 when calculating heat loss by evaporation) , GPa; S - body area, m2; C coefficient indicating the percentage of body area participating in this type of heat transfer; F8 - relative air humidity, %; Vv - air velocity in the room, m/s.

The above formula for each type of heat transfer has a different expression. This is due to differences in the mechanism of heat transfer and its dependence on the quantitative values ​​of individual factors that form the microclimate conditions. So, only the average radiating temperature of enclosing surfaces practically affects heat transfer by radiation; on heat transfer by convection, in addition to the temperature difference between the surface of the skin and air, its humidity and speed; for heat transfer by evaporation - the ratio (difference) of the maximum humidity at the average temperature of the skin surface and the absolute humidity of the ambient air.

Thus, it is possible to assess the microclimate of the room and the adequacy of the heat loss of a person in a given room using an appropriate calculation.

The impact of an unfavorable industrial microclimate on the health of workers has its own peculiarities. There are two types of pathological reactions to thermal discomfort: overheating and cooling. In accordance with this, a distinction is made between cooling, heating and the corresponding regulatory requirements(optimal and acceptable) industrial microclimate.

Cooling microclimate - a combination of microclimate parameters, in which the total heat transfer to the environment exceeds the body heat production, leading to the formation of a general and / or local heat deficit in the human body (> 0.87 kJ / kg).

Under these conditions, especially in winter period employing millions of workers. Builders, lumberjacks, fishermen, railway workers, agricultural workers work in the open air. Many people work in poorly heated rooms. The concept of a cooling microclimate includes low temperature, high humidity and air mobility, and the absence of infrared radiation. The human body in such conditions intensively gives off heat through contact of the skin with air moisture, by convection through the rapid removal of warm air from the skin and replacing it with cold air from the outside, as well as by the direct body, which has a temperature higher than the temperature of objects.

The body of the worker experiences a strong tension in the discomfort of sensations, since an increase in the mobility of xa by 1 m / s increases the sensation of cold by 1.5-2 ° C.

Increase and contraction of peripheral blood vessels, the pressure of the pulmonary circulation, which leads to an increase in the heart muscle. Workers experience pain in the body, neuropsychic abnormalities, stiffness of movements, a feeling of heaviness of clothing. All this leads to a decrease in performance.

If it decreases by more than 13% due to exposure to cold, this already poses a danger to the human body. More than 80% of people working outdoors in a favorable microclimate had cold injuries. Most of them were frostbite of the ears, nose and fingers. Approximately 20% of frostbite injuries are assessed as yellow.

Occupational morbidity due to exposure to cold among workers is quite pronounced.

The process of adaptation (addiction of the body) to the cold is long.

Under the influence of the cold factor, occupational diseases can develop: obliterating endarteritis and vegetative-sensory polyneuropathy (angioneurosis) Obliterating endarteritis (intermittent claudication) is a disease caused by narrowing of arterial vessels, often of the lower extremities. Patients complain of increased fatigue of the legs, numbness of the toes, pain in the calf muscles, a feeling of cold extremities, the pulsation of the arteries on the legs is weakened, pallor of the skin is noted. In the future, ulceration on the skin and gangrenous changes are possible.

Vegetative-sensory polyneuropathy (angioneurosis) is a neurovascular disease that occurs more often on the hands and less often on the legs. Its early sign is increased chilliness of the fingers, which is accompanied by paroxysmal pain, crawling. The skin acquires a bluish tint, becomes swollen. There is an increased vulnerability of the skin of the fingers, ulcerative processes may appear on the skin. The disease is usually located on a small area of ​​the affected limb and is characterized by periods of attenuation and renewal.

Measures to prevent the negative impact of the cooling microclimate are the observance of a rational mode of work and periodic heating in heated rooms, the cessation of work in the open at critical temperatures and air mobility established by law for a given area, the use of warm and waterproof overalls and special footwear. In the rooms and cabins there must be devices for their heating, i.e. to maintain the values ​​of the industrial microclimate corresponding to the standards (Table 5.3).

In order to detect early signs of these diseases, once or twice a year should be carried out medical examinations workers. It is advisable to remove the sick from work in cold conditions and prescribe treatment. A citizen entering work in a cooling microclimate should not be admitted to this work by a medical commission if he has a chronic vascular and peripheral nervous system disease.

Heating microclimate - a combination of microclimate parameters, in which there is a violation of heat exchange with the environment, expressed in the accumulation of heat in the body above the upper limit of the optimal value (> 0.87 kJ / kg) and / or an increase in the proportion of heat loss by sweat evaporation (> 30% ) in the general structure of the thermal balance, the appearance of general or local uncomfortable sensations (slightly warm, warm, hot).

Under these conditions, employees of hot shops work at metallurgical, machine-building enterprises, in the building materials industry, at food production and all workers whose labor activity takes place in the hot season in the open.

The concept of a heating microclimate includes elevated temperatures and humidity, the absence of air movement, the presence of infrared radiation (radiant heat).

Occupational morbidity among workers in a heating microclimate is represented by diseases of the main body systems of a working person. Morbidity with temporary disability in these workers is one and a half to two times higher than in people working in rooms with a normal microclimate, this is especially true for diseases of peptic ulcer, respiratory organs, and the genitourinary system, for which the incidence rates are 30-50 higher than those of workers in the comparison group. The female body and the body of adolescents are more sensitive than the male body to the effects of a heating microclimate.

Adaptation to the heating microclimate is slow, and only after a year can we expect the appearance of its initial signs. professional reasons industrial injuries heat and sunstroke are different.

Heat stroke occurs in workers in those rooms where there is a sharply heating microclimate, primarily due to high air temperature. The victim complains of headache, dizziness, general weakness, thirst, darkening of the eyes. Body temperature reaches 38-39 0 C, breathing usually quickens, as does the pulse, loss of consciousness is possible.

Sunstroke occurs in outdoor workers and is associated with exposure to intense infrared radiation on the brain. Clinical manifestations are approximately the same as with heat stroke, with the addition of the possibility of an excited state in the victim and the absence of an increase in body temperature. In both cases, emergency medical attention is required.

Under the influence of a heating microclimate, such an occupational disease as overheating can occur, which manifests itself both in the form of heat stroke and in the form of another pathology - a convulsive state. The latter develops as a result of continuous dehydration of the worker's body. Cramps occur in the calf, femoral muscles, muscles of the upper limbs. On examination, the casualty has dry skin, pointed facial features, rapid pulse, low blood pressure, and urination. The patient must be removed from work and prescribed treatment.

Cataract (clouding of the lens) as an occupational eye disease develops under the influence of infrared radiation (radiant heat), which is created by molten metals and mixtures. Cataracts can also be detected in workers who have contact with laser, electromagnetic radiation, and some chemical compounds. Patients note the phenomenon of dark spots in the field of vision and a decrease in its distortion of the contours of the objects under consideration, “light up” the eye in bright light. Only during a medical examination by a doctor is clouding of the lens detected.

Prevention. Assessment of microclimate parameters in accordance with SanPiI 2.2.4.548-96 "Hygienic requirements for the microclimate of industrial premises". This document outlines the optimal and permissible parameters of the microclimate of workplaces in industrial premises with the severity and duration of work, periods of the year and measurement methods.

Table 5.5

Time spent at workplaces at air temperatures below acceptable values

Air temperature at the workplace, "C

The main directions of recommendations for the improvement of working conditions are as follows: technological processes taking into account hygiene requirements, reducing the intensity of thermal radiation, heat release, moisture release from equipment by sealing it, insulating it, and arranging local suctions; improvement of heating, ventilation and air conditioning systems; rational organization of labor and placement of jobs; organization of physiologically substantiated modes of work and rest, drinking regimen; providing employees with personal protective equipment.

In accordance with SanPiI 2.2.4.548-96, in order to protect workers from possible overheating or hypothermia, the time spent at workplaces (continuously or in total per shift) that do not meet the permissible values ​​​​in terms of air temperature should be significantly limited (Table 5.4, 5.5).

Preliminary, before starting work, and periodic (once every six months, a year, two) medical examinations are carried out in order to avoid the occurrence of occupational and increase in the level of work-related diseases. Persons with chronic recurring eye diseases, expressed by vegetative-vascular dystonia and cataracts (clouding of the lens of the eye), cannot be accepted to work where there is a heating microclimate.

Meteorological conditions of the working environment

The microclimate of industrial premises is determined by a combination of temperature, humidity, air mobility, the temperature of the surrounding surfaces and their thermal radiation. Microclimate parameters determine the heat exchange of the human body and have a significant impact on the functional state of various body systems, well-being, performance and health.

The temperature in industrial premises is one of the leading factors determining the meteorological conditions of the industrial environment.

High temperatures have a negative impact on human health. Working at high temperatures is accompanied by intense sweating, which leads to dehydration of the body, loss of mineral salts and water-soluble vitamins, causes serious and persistent changes in the activity of the cardiovascular system, increases the respiratory rate, and also affects the functioning of other organs and systems - is weakened attention, coordination of movements worsens, reactions slow down, etc.

Prolonged exposure to high temperatures, especially when combined with high humidity, can lead to a significant buildup of heat in the body (hyperthermia). With hyperthermia, there is a headache, nausea, vomiting, sometimes convulsions, a drop in blood pressure, loss of consciousness.

The effect of thermal radiation on the body has a number of features, one of which is the ability of infrared rays of various lengths to penetrate to different depths and be absorbed by the corresponding tissues, providing a thermal effect, which leads to an increase in skin temperature, an increase in pulse rate, changes in metabolism and blood pressure, disease eye.

When the human body is exposed to negative temperatures, there is a narrowing of the vessels of the fingers and toes, the skin of the face, and the metabolism changes. Low temperatures also affect internal organs, and prolonged exposure to these temperatures leads to their persistent diseases.

The parameters of the microclimate of industrial premises depend on the thermophysical features of the technological process, climate, season, heating and ventilation conditions.

Thermal radiation (infrared radiation) is an invisible electromagnetic radiation with a wavelength of 0.76 to 540 nm, which has wave, quantum properties. The intensity of heat radiation is measured in W/m 2 . Infrared rays, passing through the air, do not heat it, but, being absorbed by solids, the radiant energy turns into heat, causing them to heat up. The source of infrared radiation is any heated body.

Meteorological conditions for the working area of ​​industrial premises are regulated by GOST 12.1.005-88 "General sanitary and hygienic requirements for the air of the working area" and Sanitary standards microclimate of industrial premises (SN 4088-86).

Of fundamental importance in the norms is the separate rationing of each component of the microclimate: temperature, humidity, air velocity. In the working area, microclimate parameters must be provided that correspond to the optimal and permissible values.

The fight against the adverse effects of the industrial microclimate is carried out using technological, sanitary and medical and preventive measures.

In the prevention of the harmful effects of high temperatures of infrared radiation, the leading role belongs to technological measures: the replacement of old and the introduction of new technological processes and equipment, automation and mechanization of processes, remote control.

The group of sanitary measures includes means of localization of heat releases and thermal insulation, aimed at reducing the intensity of thermal radiation and heat releases from equipment.

Effective means of reducing heat generation are:

coating of heating surfaces and steam and gas pipelines with heat-insulating materials (glass wool, asbestos mastic, asbothermite, etc.); equipment sealing; the use of reflective, heat-absorbing and heat-removing screens; arrangement of ventilation systems; usage individual means protection. Medical and preventive measures include: organization of a rational regime of work and rest; ensuring the drinking regime; increased resistance to high temperatures by using pharmacological agents (taking dibazol, ascorbic acid, glucose), inhaling oxygen; passing pre-employment and periodic medical examinations.

Measures to prevent the adverse effects of cold should include heat retention - prevention of cooling of industrial premises, selection of rational modes of work and rest, use of personal protective equipment, as well as measures to increase the body's defenses.

Bibliography

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