1. The concept of maximum permissible concentration

1.1 The value of harmfulness indicators MPC

2. Types of maximum permissible concentrations

2.1 MPC for the air environment

2.2 MPC for the aquatic environment

2.3 MPC in the arable soil layer

2.4 MAC in food products

3. Maximum permissible levels

3.1 Maximum permissible radiation level

3.2 Maximum permissible noise level

3.3 Maximum permissible vibration level

3.4 Maximum permissible level of ionizing radiation

Bibliography

1. The concept of maximum permissible concentration

1.1 The value of harmfulness indicators of maximum permissible concentrations

Maximum permissible concentration(hereinafter MPC) is a sanitary and hygienic standard approved by law. MPC refers to standards that are established in accordance with the maximum permissible content of chemical substances, including radioactive, other substances and microorganisms in the environment and non-compliance with which can lead to environmental pollution and degradation of natural ecological systems 1 . This is the maximum concentration of a harmful substance, which over a certain period of exposure does not affect the health of a person and his offspring, as well as the components of the ecosystem and the natural community as a whole.

The standards for maximum permissible harmful effects, as well as methods for determining them, are temporary and can be improved as science and technology develop, taking into account international standards.

The main environmental standards for environmental quality and impact on it are as follows:

1. maximum permissible concentration (MPC) of harmful substances;

2. maximum permissible level (MPL) of harmful physical influences: radiation, noise, vibration, magnetic fields, etc.

The MPC value is established by law. Therefore, MPC can be considered a concept more legal than natural science (although MPC values ​​are determined on the basis of scientific recommendations). And that’s why different countries adopt their own standards for maximum permissible concentrations, which can differ from each other by several times and even orders of magnitude. This should always be kept in mind when comparing the results of environmental studies carried out in different countries, including neighboring ones (for example, when specialists from two neighboring countries assess, independently of each other, the consequences of one man-made accident that occurred in a border area). However, there are general standards recommended by the World Health Organization (WHO), and it is recommended that national standards be no less stringent. But the tightening of national standards in comparison with international ones is quite acceptable and even encouraged.

The values ​​of toxicity and maximum permissible concentrations are generally related in an inverse proportion. The more toxic the substance, the lower the MPC value. MPC values ​​are established not only for each substance separately, but also for each of the environments in which it may be contained. Each medium uses its own units of measurement: for soil – mg/kg, water – mg/l, air – mg/m3.

The maximum permissible concentration value is established taking into account various indicators of harmfulness associated with the characteristics of the impact on the body or methods of transfer (exchange between environments). In particular, to assess the value of the maximum permissible concentration in soils, since the soil substance does not have a direct effect on the human body, several indicators of such a possible indirect effect are used:

the water migration indicator takes into account the ability of a substance to form soluble forms, be transmitted through the aquatic environment and, accordingly, enter the human body when drinking water;

the air indicator takes into account the “volatility” of a substance, its ability to evaporate and be transported through the air, entering the human body during respiration;

the translocation indicator takes into account the ability of a chemical element to accumulate in plants and enter the human or animal body when consumed as food;

an indicator based on the harmfulness of direct entry of a toxic substance into the body is called sanitary-toxicological;

for atmospheric air and natural waters used for water supply, an organoleptic indicator can be used that takes into account not only the toxic effect, but also the appearance of unpleasant sensations when inhaling polluted air or drinking contaminated water;

Ultimately, the one that is the most stringent is taken as the final, limiting indicator when establishing the MPC. When establishing maximum permissible concentrations for the air environment, not only the content of the substance is taken into account, but also the time that a person can spend in this atmosphere without harm to health. This is due to the fact that the impact of toxic substances dispersed in the atmosphere is not one-time, but occurs continuously during the breathing process. The longer a person stays in a polluted atmosphere, the greater the danger to his health.

For the most toxic substances, MPC values ​​are not established. This means that any, even the most insignificant, content of them in natural environments poses a danger to human health. Some substances that are synthesized artificially and have no natural analogues can have such a high degree of toxicity.

Under air quality understand - the totality of atmospheric properties that determine the degree of influence of physical, chemical and biological factors on people, flora and fauna, as well as on materials, structures and the environment as a whole.

Permissible limits for the content of harmful substances both in the industrial zone (intended to accommodate industrial enterprises, pilot production of research institutes, etc.) and in the residential zone (intended to accommodate housing stock, public buildings and structures) of settlements. Basic terms and definitions related to atmospheric pollution indicators, observation programs, and the behavior of impurities in atmospheric air are defined by GOST GN 2.2.5.1313-03. 2

A feature of the standardization of atmospheric air quality is the dependence of the impact of pollutants present in the air on the health of the population not only on the value of their concentrations, but also on the duration of the time interval during which a person breathes this air.

Maximum permissible concentrationmaximally one-time (maximum permissible concentrationm.r.) – maximum 20-30 minute concentration, under the influence of which no reflex reactions occur in humans (breath holding, irritation of the mucous membrane of the eyes, upper respiratory tract, etc.).

Maximum permissible concentration, average daily(maximum permissible concentration ss ) – this is the concentration of a harmful substance in the air of populated areas, which should not have a direct or indirect effect on a person if inhaled for an unlimited period of time (years). Thus, the maximum permissible concentration ss is designed for all groups of the population and for an indefinitely long period of exposure and, therefore, is the most stringent sanitary and hygienic standard establishing the concentration of a harmful substance in the air.

Maximum permissible concentration of harmful substances in the air of the working area(MPC rz) - a concentration that, during daily (except for weekends) work for 8 hours, or for another duration, but not more than 41 hours per week, throughout the entire working experience should not cause diseases or deviations in the state of health detected modern research methods, in the process of work or in the long term of the life of the present and subsequent generations. A working area should be considered a space up to 2 m high above the floor or area where workers permanently or temporarily reside.

Based on the nature of their impact on the human body, harmful substances can be divided into groups: irritants (chlorine, ammonia, hydrogen chloride, etc.); asphyxiants (carbon monoxide, hydrogen sulfide, etc.); narcotics (nitrogen under pressure, acetylene, acetone, carbon tetrachloride, etc.); somatic, causing disturbances in the functioning of the body (lead, benzene, methyl alcohol, arsenic).

According to the requirements of sanitary standards and the Occupational Safety Standards System, enterprises must monitor the content of harmful substances in the air of the working area (occupational safety). Where highly dangerous hazardous substances of the first class are used, monitoring is continuous, using automatic recording devices that issue a signal when the limit is exceeded. Where hazardous substances of the second, third and fourth classes are used, periodic monitoring must be carried out by taking and analyzing air samples. Selection is carried out in the breathing zone within a radius of up to 0.5 m from the worker’s face; At least five samples are taken during the shift. Harmful substances of unidirectional action include harmful substances that are similar in chemical structure and the nature of the biological effect on the human body.

In our country, MPCs are set by the sanitary authorities of the Russian Ministry of Health. Periodically, in accordance with the level of development of medical knowledge, MPCs are revised, usually in the direction of tightening.

Hazard class is an indicator characterizing the degree of danger to humans of substances that pollute atmospheric air. Based on the degree of impact on the body, harmful substances are divided into four hazard classes:

2.2 MPC for the aquatic environment bottom

Under water quality generally understood as a characteristic of its composition and properties, determining its suitability for specific types of water use; in this case, quality indicators are signs by which water quality is assessed. MPC is the maximum concentration of a substance in water, which, when entering the body throughout life, should not have a direct or indirect effect on the health of the population in the present and subsequent generations, including in the long term, and also not worsen the hygienic conditions of water use.

The maximum permissible concentration in the water of a reservoir for domestic, drinking and cultural water use (MPC v) is the concentration of a harmful substance in water, which should not have a direct or indirect effect on the human body throughout his life and on the health of subsequent generations, and not should worsen the hygienic conditions of water use 3. The maximum concentration of a substance in water, which, when entering the body throughout life, should not have a direct or indirect effect on the health of the population in the present and subsequent generations, including in the long term, and also not worsen the hygienic conditions of water use.

Maximum permissible concentration in the water of a reservoir used for fishing purposes(MPC vp) is the concentration of a harmful substance in water, which should not have a harmful effect on fish populations, primarily commercial ones 4 .

Water quality in general refers to the characteristics of its composition and properties, which determine its suitability for specific types of water use; in this case, quality indicators are signs by which water quality is assessed. The maximum permissible concentration (MAC) of a chemical substance in the water of water bodies for domestic, drinking and cultural water use is a hygienic standard approved by a decree of the Chief State Sanitary Doctor of the Russian Federation on the recommendation of the Commission on Sanitary and Epidemiological Standards under the Ministry of Health of Russia.

Commissioning of enterprises, workshops and technologies is possible only if there are MPCs and methods for determining substances in water approved in accordance with the established procedure. The development of maximum permissible concentrations of substances is carried out in departments of scientific institutions, higher educational institutions, sanitary and epidemiological stations that have received accreditation from the Department of State Sanitary and Epidemiological Surveillance of the Ministry of Health of Russia. 5 In accordance with the Sanitary Rules and Standards, drinking water must be safe in terms of epidemics and radiation, harmless in chemical composition and must have favorable organoleptic properties. 6

Requirements for the quality of water from non-centralized water supply are determined by the Sanitary Rules and Norms, which standardize odor, taste, color, turbidity, coli-index, and also indicate that the content of chemicals should not exceed the corresponding maximum permissible concentrations (MPC).

When interpreting the results of monitoring the state of the aquatic environment, it is important to know what type of water body a river, lake, or reservoir is classified as, and to use the appropriate standards to assess the situation. In hydrochemical practice, the method of integral assessment of water quality is also used, based on the totality of pollutants contained in it and the frequency of their detection. In this method, for each ingredient, based on actual concentrations, scores are calculated for the multiplicity of excess of the MAC BP and the frequency of occurrence of exceedances, as well as an overall assessment score.

Under air quality understand - the totality of atmospheric properties that determine the degree of influence of physical, chemical and biological factors on people, flora and fauna, as well as on materials, structures and the environment as a whole.

Permissible limits for the content of harmful substances both in the industrial zone (intended to accommodate industrial enterprises, pilot production of research institutes, etc.) and in the residential zone (intended to accommodate housing stock, public buildings and structures) of settlements. Basic terms and definitions relating to atmospheric pollution indicators, observation programs, and the behavior of impurities in atmospheric air are defined by GOST 17.2.1.03-84. GOST 17.2.1.03-84. Protection of Nature. Atmosphere. Pollution control terms and definitions.

A feature of the standardization of atmospheric air quality is the dependence of the impact of pollutants present in the air on the health of the population not only on the value of their concentrations, but also on the duration of the time interval during which a person breathes this air.

Maximum permissible maximum single concentration (MPC) m.r.) - a maximum 20-30 minute concentration, under the influence of which no reflex reactions occur in humans (breath holding, irritation of the mucous membrane of the eyes, upper respiratory tract, etc.).

Maximum permissible average daily concentration (MPC) ss) is the concentration of a harmful substance in the air of populated areas, which should not have a direct or indirect effect on a person if inhaled for an unlimited period of time (years). Thus, the maximum permissible concentration ss is designed for all groups of the population and for an indefinitely long period of exposure and, therefore, is the most stringent sanitary and hygienic standard establishing the concentration of a harmful substance in the air.

Maximum permissible concentration of harmful substances in the air of the working area(MPC rz) - a concentration that, during daily (except weekends) work for 8 hours, or for another duration, but not more than 41 hours per week, throughout the entire working experience should not cause diseases or deviations in the state of health detected modern research methods, in the process of work or in the long term of the life of the present and subsequent generations. A working area should be considered a space up to 2 m high above the floor or area where workers permanently or temporarily reside.

As follows from the definition, the MPC of the Republic of Lithuania is a standard that limits the exposure of the adult working population to a harmful substance during the period of time established by labor legislation. GN 2.2.5.686-98 Maximum permissible concentrations (MPC) of harmful substances in the air of the working area.

Based on the nature of their impact on the human body, harmful substances can be divided into groups: irritants (chlorine, ammonia, hydrogen chloride, etc.); asphyxiants (carbon monoxide, hydrogen sulfide, etc.); narcotics (nitrogen under pressure, acetylene, acetone, carbon tetrachloride, etc.); somatic, causing disturbances in the functioning of the body (lead, benzene, methyl alcohol, arsenic).

According to the requirements of sanitary standards and the Occupational Safety Standards System, enterprises must monitor the content of harmful substances in the air of the working area (occupational safety). Where highly dangerous hazardous substances of the first class are used, monitoring is continuous, using automatic recording devices that issue a signal when the limit is exceeded. Where hazardous substances of the second, third and fourth classes are used, periodic monitoring must be carried out by taking and analyzing air samples. Selection is carried out in the breathing zone within a radius of up to 0.5 m from the worker’s face; At least five samples are taken during the shift. Harmful substances of unidirectional action include harmful substances that are similar in chemical structure and the nature of the biological effect on the human body.

When several harmful substances that do not have a unidirectional action are simultaneously released into the air of the working area of ​​the premises, the amount of air when calculating general ventilation should be taken according to the harmful substance that requires the supply of the largest volume of clean air.

In our country, MPCs are set by the sanitary authorities of the Russian Ministry of Health. Periodically, in accordance with the level of development of medical knowledge, MPCs are revised, usually in the direction of tightening. For example, until 1968, standards were in force providing for the maximum permissible concentration for benzene of 20 mg/m 3. Clinical and hygienic studies have revealed cases of adverse effects of such concentrations on the human body. This served as the basis for reducing the maximum permissible concentration of benzene to 5 mg/m 3 . In general, we can say that all maximum permissible concentrations tend to certain limits, usually called maximum permissible environmental concentrations (MPEC). This refers to concentrations of harmful substances that do not have a harmful effect (immediate or remote) on ecological systems, i.e. on the totality of living organisms, habitats and their interrelationships.

Currently, MPCs have been established for working area air for more than 850 substances.

MPC for air in residential premises, schools, preschool institutions and public buildings - 0.0003 mg/cub.m. MPC for production facilities, educational laboratories of universities and research institutes is 0.0017 mg/cub.m., i.e. 30% of the average shift maximum permissible concentration of the working area, equal to 0.005 mg/cub.m (GOST 12.1.005-76 “Working area air. General sanitary and hygienic requirements”).

Hazard class is an indicator characterizing the degree of danger to humans of substances that pollute the atmospheric air. According to the degree of impact on the body, harmful substances are divided into four hazard classes GOST 12.1.007-76 “Classification and general safety requirements”:

MAXIMUM ALLOWABLE CONCENTRATION (MAC) OF HARMFUL SUBSTANCES- this is the maximum concentration of a harmful substance, which over a certain period of exposure does not affect the health of a person and his offspring, as well as the components of the ecosystem and the natural community as a whole.

Many impurities enter the atmosphere from various industrial production and vehicles. To control their content in the air, well-defined standardized environmental standards are needed, which is why the concept of maximum permissible concentration was introduced. MPC values ​​for air are measured in mg/m3. MPCs have been developed not only for air, but also for food products, water (drinking water, reservoir water, wastewater), and soil.

The maximum concentration for a work area is considered to be such a concentration of a harmful substance that, during daily work throughout the entire working period, cannot cause illness during work or in the long-term life of the present and subsequent generations.

Ambient air concentration limits are measured in populated areas and refer to a specific time period. For air, there is a maximum single dose and an average daily dose.

Depending on the MPC value, chemicals in the air are classified according to the degree of danger. For extremely hazardous substances (mercury vapor, hydrogen sulfide, chlorine), the maximum permissible concentration in the air of the working area should not exceed 0.1 mg/m3. If the maximum permissible concentration is more than 10 mg/m3, then the substance is considered low-hazard. Such substances include, for example, ammonia.

MPCs are established for the average person, however, people weakened by illness and other factors may feel uncomfortable at concentrations of harmful substances that are less than MPCs. This, for example, applies to heavy smokers.

The maximum permissible concentrations of certain substances in a number of countries vary significantly. Thus, the maximum permissible concentration of hydrogen sulfide in atmospheric air during 24-hour exposure in Spain is 0.004 mg/m3, and in Hungary – 0.15 mg/m3 (in Russia – 0.008 mg/m3).

In our country, standards for maximum permissible concentrations are developed and approved by the sanitary-epidemiological service and government agencies in the field of environmental protection. Environmental quality standards are uniform for the entire territory of the Russian Federation. Taking into account the natural and climatic features, as well as the increased social value of individual territories, standards for maximum permissible concentrations, reflecting special conditions, can be established for them.

If several harmful substances of unidirectional action are simultaneously present in the atmosphere, the sum of the ratios of their concentrations to the maximum permissible concentration should not exceed one, but this is not always the case. According to some estimates, 67% of the Russian population live in regions where the content of harmful substances in the air is higher than the established maximum permissible concentration. In 2000, the content of harmful substances in the atmosphere in 40 cities with a total population of about 23 million people from time to time exceeded the maximum permissible concentration by more than ten times.

Impact levels of thermal power plants in Moscow.

When assessing pollution hazards, studies conducted in biosphere reserves serve as a reference point. But in large cities the natural environment is far from ideal. Thus, based on the content of harmful substances, the Moscow River within the city is considered a “dirty river” and a “very dirty river.” At the exit of the Moskva River from Moscow, the content of petroleum products is 20 times higher than the maximum permissible concentrations, iron – 5 times, phosphates – 6 times, copper – 40 times, ammonia nitrogen – 10 times. The content of silver, zinc, bismuth, vanadium, nickel, boron, mercury and arsenic in the bottom sediments of the Moscow River exceeds the norm by 10–100 times. Heavy metals and other toxic substances from water enter the soil (for example, during floods), plants, fish, agricultural products, and drinking water, both in Moscow and downstream in the Moscow region.

Chemical methods for assessing environmental quality are very important, but they do not provide direct information about the biological hazard of pollutants - this is the task of biological methods. Maximum permissible concentrations are certain standards for the gentle impact of pollutants on human health and the natural environment.

Chemistry and society. Per. from English – M., Mir, 1995
Khabarova E.I., Panova S.A. Ecology in tables. Reference manual. M., Bustard, 1999
Man and his environment. Reader. Ed. G.V. Lisichkina and N.N. Chernova. M., Mir, 2003

Environmental problems are becoming increasingly acute for modern humanity. A particularly serious issue is the quality of air, which is polluted by exhaust gases and emissions from industrial enterprises. To meet the enemy fully armed, you should familiarize yourself with the maximum permissible concentrations of harmful substances in the air.

Maximum concentrations of harmful substances in atmospheric air

What is MPC? MPC is the maximum permissible concentration of chemical elements and their compounds in the air, which does not cause negative consequences in living organisms. Standards for maximum permissible concentrations of harmful substances are approved by law and controlled by sanitary and epidemiological services (in Russia - Rospotrebnadzor) using toxicological studies. The maximum permissible concentration for each substance hazardous to health is included in GOSTs, compliance with which is mandatory. If any enterprise violates the MPC norms, it will be fined or even closed down. The maximum permissible concentration is set for people who are most susceptible to the influence of chemicals (children, elderly people, people with respiratory diseases, etc.). The MPC value for air is measured in mg/m3; there is also a maximum permissible concentration for water, soil and food.

Maximum concentration limits for harmful substances in atmospheric air vary:

• MPC MR – maximum single concentration of a substance. It should not affect living organisms for 20–30 minutes.
• MPC SS – average daily concentration. This maximum permissible concentration should not have a negative impact on living organisms for an indefinitely long time.

Hazard classes of substances

Based on the degree of impact on the body, harmful substances are divided into four hazard classes. Each hazard class has its own maximum permissible concentration. The following hazard classes of substances in atmospheric air are distinguished:

1. extremely dangerous substances (maximum concentration limit less than 0.1 mg/m3);
2. highly hazardous substances (MPC 0.1–1 mg/m3);
3. moderately hazardous substances (MPC 1.1–10 mg/m3);
4. low-hazard substances (maximum permissible concentration more than 10 mg/m3).

There is also a classification of harmful substances according to their effect on a living organism. Moreover, some substances belong to several classes at once:

• Generally toxic – substances that cause poisoning of the body as a whole. When exposed to them, convulsions, nervous system disorders, and paralysis are observed.
• Irritants – substances that affect the skin, mucous membrane of the respiratory tract, lungs, eyes, nasopharynx. Long-term exposure leads to respiratory problems, intoxication and death.
• Sensitizers are chemicals that cause an allergic reaction.
• Carcinogens are one of the most dangerous groups of substances that provoke the occurrence of cancer.
• Mutagens are substances that change a person’s genotype. They reduce the body's resistance to disease, cause early aging and can affect the health of the offspring.
• Affecting reproductive health - substances that cause developmental abnormalities in the offspring (not necessarily in the first generation).

Below is a table of the maximum permissible concentrations for some harmful substances in atmospheric air, established in the Russian Federation:

Carbon monoxide (CO)

Another name for carbon monoxide, carbon monoxide, is familiar to us from an early age. It is often found in everyday life - for example, CO is released due to malfunctions of gas water heaters and kitchen stoves. For poisoning with this gas, a very small concentration is needed. Carbon monoxide is colorless and odorless, which makes it even more dangerous. Intoxication occurs rapidly; a person can lose consciousness in a matter of seconds. Despite the fact that the hazard class of carbon monoxide is fourth, its exposure leads to death in just a few minutes. If you feel difficulty breathing, headache, lack of concentration, decreased hearing and vision, you must, if possible, open all windows and doors and leave the room as quickly as possible.

Ammonia (NH3)

Ammonia is a colorless gas with a sharp, pungent odor. It is known to most as a ten percent aqueous solution - ammonia. Although inhaling ammonia vapor has a stimulating effect and helps with fainting, you should be careful with this gas. Ammonia irritates the mucous membrane of the eyes, causes suffocation, and in high concentrations leads to corneal burns and blindness, affects the nervous system to the point of irreversible changes, reduces the cognitive functions of the brain, and provokes hallucinations.

Xylene (C8H10)

Xylene belongs to the third class of danger; it can cause acute and chronic damage to the hematopoietic organs. Xylene is a colorless liquid, but with a characteristic odor, which is used as an organic solvent for the manufacture of plastics, varnishes, paints, and construction adhesives. In small concentrations, xylene does not harm humans in any way, but with prolonged inhalation of xylene vapors, drug addiction appears. Xylene also affects the nervous system and causes irritation to the skin and mucous membranes of the eyes.

Nitric oxide (NO)

Nitric oxide is a toxic, colorless gas. It does not irritate the respiratory tract, so it is difficult for a person to feel it. NO reacts with hemoglobin and forms methemoglobin, which blocks the airways and causes oxygen deprivation. When interacting with oxygen, the gas turns into nitrogen dioxide (NO2).

Sulfur dioxide (SO2)

Sulfur dioxide, or sulfur dioxide, has a characteristic odor similar to that of a burning match. Inhaling SO2, even in small concentrations, can lead to inflammation of the respiratory tract, causing coughing, runny nose and hoarseness. Long-term exposure provokes speech defects, a feeling of lack of air, and pulmonary edema. Damage to lung tissue is also possible, but this does not appear until several days after exposure. People with diseases of the respiratory system, for example, are most susceptible to the effects of SO2.

Toluene (C7H8)

Toluene enters the human body not only through the respiratory system, but also through the skin. Symptoms of toluene poisoning are irritation of the mucous membrane of the eyes, lethargy, disruption of the vestibular apparatus, hallucinations. Toluene is also extremely fire hazardous and has a narcotic effect. Until 1998, it was part of Moment glue and is still contained in some varnish and paint solvents.

Hydrogen sulfide (H2S)

Hydrogen sulfide is a colorless gas with an odor reminiscent of rotten eggs. Being highly toxic, H2S primarily affects the nervous system, causing severe headaches, seizures and can lead to coma. The lethal concentration of hydrogen sulfide is approximately 1,000 mg/m3. At a concentration of 6 mg/m3, headaches, dizziness and nausea begin.

Chlorine (Cl2)

Chlorine gas has a yellow-green color and a pungent, irritating odor. Some of the first symptoms of chlorine poisoning are red eyes, coughing attacks, chest pain, and increased body temperature. Possible development of bronchopneumonia and bronchitis. Being a strong carcinogen, chlorine provokes the occurrence of cancer and tuberculosis. At high concentrations, death can occur after a few breaths.

Formaldehyde (HCOH)

The content in the air is especially high in large cities, since it is a product of combustion of vehicle fuel. Formaldehyde emissions also occur in chemical, tanning and wood processing plants. It negatively affects genetic material, reproductive and respiratory systems, liver, and kidneys. Poisoning begins with increasing damage to the nervous system - with dizziness, feelings of fear, trembling, uneven gait, etc. Formaldehyde is officially recognized as a carcinogen, but it also has allergenic, mutagenic and sensitizing effects.

Nitrogen dioxide (NO2)

Nitrogen dioxide is a poisonous gas of red-brown color with a characteristic pungent odor. It is formed as a result of the combustion of automobile fuel, the activities of thermal power plants and industrial enterprises. At the initial stage of exposure, nitrogen dioxide disrupts the functioning of the upper respiratory tract, and subsequently can cause bronchitis, inflammation or pulmonary edema. This gas is most dangerous for people suffering from bronchial asthma and other pulmonary diseases. Because of the color of nitrogen dioxide, its emissions are called “foxtail.” This gas is associated with the fox not only by its color, but also by its cunning: in order to “hide” from people, it impairs the sense of smell and vision, so it is not so easy to detect.

Phenol (C6H5OH)

Phenol is one of the industrial pollutants that is harmful to animals and humans. When inhaling phenol vapors, loss of strength, nausea, and dizziness occur. Phenol negatively affects the nervous and respiratory systems, as well as the kidneys, liver, etc. The use of phenol often leads to disastrous consequences. In the seventies in the USSR it was used in the construction of residential buildings. People who lived in “phenolic houses” complained of poor health, allergies, cancer and other ailments. Although phenol-formaldehyde resins are used in furniture, building materials and much more, unscrupulous manufacturers may exceed the permitted limit or use substandard chemicals.

Benzene (C6H6)

Benzene is a dangerous carcinogen. In case of benzene vapor poisoning, a person experiences headache, nausea, mood swings, heart rhythm disturbances, and sometimes fainting. Constant exposure to benzene on the body is manifested by fatigue, bone marrow dysfunction, leukemia, and anemia. Often the first sign of benzene poisoning is euphoria, since inhaling its vapors has a narcotic effect. This chemical compound is part of gasoline and is used to produce plastics, dyes, and synthetic rubber.

Ozone (O3)

This gas, which has a characteristic odor and is blue in color at high concentrations, protects us from ultraviolet radiation from the sun. Ozone is a natural antiseptic and disinfects water and air. Another thing that speaks in favor of ozone is that the air after a thunderstorm, saturated with ozone, seems fresh and invigorating to us. Unfortunately, ozone causes extremely unpleasant consequences. It aggravates allergies, aggravates heart disease, reduces immunity and causes breathing problems. Ozone acts slowly, but is extremely harmful in the long term - this gas is especially dangerous for children, the elderly and asthmatics.