Our planet is surrounded by an air envelope – an atmosphere that extends over the Earth for 1,500-2,000 km upwards, which is about 1/3 of the Earth’s radius. However, this limit is conditional, traces of atmospheric air were also detected at an altitude of 20,000 km.
The presence of an atmosphere is one of the necessary conditions for the existence of life on Earth. The atmosphere regulates the Earth’s climate, daily temperature fluctuations on the planet (without it, they would reach 200°C). Currently, the average temperature of the Earth’s surface is 14oC. The atmosphere passes the heat radiation of the Sun and stores the heat, clouds, rain, snow, and wind will form there. It also plays the role of a carrier of moisture on Earth, is a medium for the propagation of sound (without air, the earth would be silent). The atmosphere serves as a source of oxygen breath, perceives gaseous metabolic products, affects heat exchange and other functions of living organisms. Oxygen and nitrogen, whose content in the air is 21% and 78%, respectively, are of main importance for the vital activity of the body.
Oxygen is necessary for the respiration of most living things (the exception is only a small number of anaerobic microorganisms). Nitrogen is part of proteins and nitrogenous compounds, the origin of life on earth is connected with it. Carbon dioxide is a source of carbon in organic substances – the second most important component of these compounds.
During the day, a person inhales about 12-15 m3 of oxygen, and emits about 580 liters of carbon dioxide. Therefore, atmospheric air is one of the main vital elements of our environment.
It should be noted that its chemical composition is quite stable in areas far from the sources of pollution. However, as a result of human economic activity, sources of pronounced pollution of the air pool appeared in those areas where large industrial centers are located. Here in the atmosphere, the presence of various solid and gaseous substances is noted, which have an adverse effect on the living conditions and health of the population.
Until now, a lot of scientific data has accumulated that the pollution of the atmosphere, especially in large cities, has reached dangerous levels for people’s health. Many cases of illness and even death of residents of cities in industrial centers are known as a result of emissions of toxic substances by industrial enterprises and transport under certain meteorological conditions. In this regard, the literature often mentions catastrophic cases of poisoning of people in the Meuse Valley (Belgium), in the city of Donor (USA), in London, Los Angeles, Pittsburgh and a number of other large cities not only in Western Europe, but also in Japan , China, Canada, Russia, etc.
Silicon dioxide and free silicon contained in fly ash are the cause of severe lung disease, which develops in workers of “dusty” professions, for example, miners, workers of coke, coal, cement and a number of other enterprises. Lung tissue is replaced by connective tissue, and these areas cease to function. Children who live near powerful power plants, which are not equipped with dust collectors, show changes in the lungs similar to forms of silicosis. Heavy air pollution with smoke and soot, which continues for several days, can cause poisoning of people with fatal results.
Atmospheric pollution has a particularly harmful effect on people in those cases when meteorological conditions contribute to stagnation of air over the city.
Harmful substances contained in the atmosphere affect the human body in contact with the surface of the skin or mucous membrane. Along with the respiratory organs, pollutants affect the organs of vision and smell, and affecting the mucous membrane of the larynx, they can cause spasms of the vocal cords. Inhaled solid and liquid particles with sizes of 0.6-1.0 microns reach the alveoli and are absorbed into the blood, some accumulate in the lymph nodes.
Polluted air mostly irritates the respiratory tract, causing bronchitis, emphysema, and asthma. The irritants that cause these diseases include SO2 and SO3, nitrogen vapors, HCl, HNO3, H2SO4, H2S, phosphorus and its compounds. Dust containing silicon oxides causes a serious lung disease – silicosis. Studies conducted in Great Britain have shown a very close connection between air pollution and mortality from bronchitis.
Street eye injuries caused by fly ash and other atmospheric pollutants in industrial centers reach 30-60% of all cases of eye diseases, which are very often accompanied by various complications, conjunctivitis.
Signs and consequences of the effects of air pollutants on the human body are manifested mostly in the deterioration of the general state of health: headaches, nausea, feelings of weakness appear, work capacity decreases or is lost. Certain pollutants cause specific symptoms of poisoning. For example, chronic phosphorus poisoning is initially manifested by pain in the gastrointestinal tract and yellowing of the skin. These symptoms are accompanied by loss of appetite and slowing of metabolism. In the future, phosphorus poisoning leads to deformation of the cysts, which become more and more fragile. The resistance of the body as a whole decreases.
CO. Colorless, odorless gas. Affects the nervous and cardiovascular system, causes suffocation. The primary symptoms of carbon monoxide poisoning (occurrence of headache) occur in a person after 2-3 hours of his stay in an atmosphere containing 200-220 mg/m3; at higher concentrations of CO, there is a feeling of pulse in the temples, dizziness. The toxicity of CO increases with the presence of nitrogen in the air, in this case the concentration of CO in the air must be reduced by 1.5 times.
Nitrogen oxides. NO N2O3 NO5 N2O4. Nitrogen dioxide NO2 is mainly released into the atmosphere – a colorless, odorless, poisonous gas that irritates the respiratory system.
Nitrogen oxides are especially dangerous in cities, where they interact with carbon in exhaust gases and form photochemical fog – smog. Air poisoned by nitrogen oxides begins to act with a slight cough. When the concentration of NO increases, there is a strong cough, vomiting, and sometimes a headache. Upon contact with the moist surface of the mucous membrane, nitrogen oxides form HNO3 and HNO2 acids, which lead to pulmonary edema.
SO2 is a colorless gas with a sharp smell, even in small concentrations (20-30 mg/m3) it creates an unpleasant taste in the mouth, irritates the mucous membranes of the eyes and respiratory tract. Inhalation of SO2 causes disease-causing phenomena in the lungs and respiratory tract, sometimes swelling of the lungs, pharynx and respiratory paralysis occur. The effect of carbon disulfide is accompanied by severe nervous disorders, impaired mental activity.
Hydrocarbons (gasoline vapors, methane, etc.) have a narcotic effect, in small concentrations they cause headaches, dizziness, etc. Thus, inhalation of gasoline vapors at a concentration of 600 mg/m3 for 8 hours causes headaches, cough, and unpleasant sensations in the throat.
Aldehydes. With long-term exposure to humans, aldehydes cause irritation of the mucous membranes of the eye and respiratory tract, and with increased concentration, headache, weakness, loss of appetite, and insomnia are noted.
Lead compounds. Approximately 50% of lead compounds enter the body through the respiratory system. Under the action of lead, the synthesis of hemoglobin is disturbed, diseases of the respiratory tract, genitourinary organs, and the nervous system occur. Lead compounds are especially dangerous for preschool children. In large cities, the content of lead in the atmosphere reaches 5-38 mg/m3, which exceeds the natural background by 10,000 times.
Signs of sulfur dioxide poisoning are determined by the characteristic taste and smell. At a concentration of 6-20 cm3/m, it causes irritation of the mucous membranes of the nose, throat, and eyes, and irritated moist areas of the skin. Polycyclic aromatic hydrocarbons of the 3,4-benzopyrene (C20H12) type, which are formed during incomplete combustion of fuel, are especially dangerous. According to a number of scientists, they have carcinogenic properties.
The dispersed composition of dust and fog determines the general permeability of harmful substances to the human body. A special danger is posed by toxic finely dispersed powders with a particle size of 0.5-1.0 microns that easily penetrate the respiratory system.
Finally, various manifestations of discomfort in connection with air pollution – unpleasant odors, reduced illumination, and others – have a psychologically negative effect on people.
Harmful substances in the atmosphere and falling out also affect animals. For example, in Austria, lead accumulated in the bodies of hares that ate grass along the highways. Three such hares eaten in one week is quite enough for a person to fall ill as a result of lead poisoning.
In addition, together with emissions into the atmosphere, the national economy loses many valuable products. Some emitted substances destroy metal structures, concrete, natural building stone materials, etc., thereby causing damage to industrial facilities and architectural monuments.
Monitoring studies have shown that changes in the amount and properties of pollutants, including toxicants, in drinking water, food products, soils, and especially in the atmosphere cause changes in the health of the population. This relationship is most clearly reflected in the dynamics of allergic and respiratory diseases.
Allergic diseases (allergy) are human diseases characterized by changes in the body’s reactivity to repeated exposures and increased sensitivity to exogenous allergens.
Allergens are substances of an antigenic or hyptenic nature that cause allergies.
Allergens can be protein, protein-polysaccharide and protein-lipid complexes, complex compounds of a non-protein nature and simple chemical substances, including individual elements (bromine, iodine, others).
Simple chemicals become allergens after combining with body tissue proteins. At the same time, the specificity of the protein either changes or remains the same.
All allergens are divided into two groups: endoallergens (formed in the body itself) and exoallergens (entering the body from the outside).
Exoallergens, in turn, are divided into subgroups:
– airborne, inhaled allergens (household and industrial dust, plant pollen, animal hair, and others);
– food allergens (most often eggs, meat, fish, tomatoes, milk, chocolate);
– contact allergens that pass through mucous membranes and skin (chemical substances, medical preparations);
– injectable allergens (sera, medicines);
– infectious allergens (bacteria, viruses);
– medical allergens.
In the conditions of a big city, industrial, airborne, inhalation allergens that cause respiratory allergies play a major role.
Substances in the air we breathe, including allergens, enter the body through the mucous membrane of the upper respiratory tract. Under the influence of harmful factors (passive smoking, infections), the protective mechanisms of mucous membranes weaken and conditions are created for easy penetration of allergens into the human body.
Respiratory allergies include: allergic rhinitis, lesions of the nasal sinuses – sinusitis; damage to the pharynx – allergic angina, damage to the pharynx – pharyngitis; damage to the trachea – tracheitis; lesions of the bronchi – bronchitis, which are often harbingers of bronchial asthma in children.
Allergic rhinitis is the most common manifestation of allergy. Usually, the process begins in the nasal sinuses, and then spreads to the pharynx and pharynx. Bronchi, sometimes in the middle ear, causing its inflammation – otitis. Often, a runny nose is accompanied by watery discharge from the nose, itching, fever, sometimes urticaria and edema.
Allergic damage to the pharynx – pharyngitis, is accompanied by swelling, redness of the throat, the back wall of the pharynx, swelling of the lips, tongue, and allergic rash on the skin.
The most dangerous are allergic diseases of the oral cavity and larynx, which are accompanied by swelling of the larynx, which narrows (and sometimes closes) the lumen, causing asphyxia.
Allergic tracheitis and bronchitis are characterized by repeated bouts of coughing, sometimes vomiting mucous. But allergic tracheitis does not cause a general deterioration of a person’s condition: there are no shortness of breath and wheezing in the lungs.
Allergic bronchitis, unlike tracheitis, has a persistent nature and subsequently causes bronchial asthma with complications.
Nowadays, non-specific diseases of the respiratory system occupy the third place among the causes of mortality of the population, second only to cardiovascular diseases and oncology. The specific weight of chronic bronchitis among non-specific lung diseases reaches 60-65%. In the structure of occupational diseases in Ukraine, chronic bronchitis ranks second after pneumoconiosis. However, in the last 2 years, there has been a tendency to increase the number of patients with chronic bronchitis, which has led to an equalization of the incidence rates of chronic bronchitis and pneumoconiosis.
The complexity of the etiology and pathogenesis of chronic bronchitis makes it necessary to take into account a number of exogenous and endogenous risk factors that contribute to their development. The main ones are smoking, atmospheric air pollution with various pollutants (smoke, smog, irritating chemicals). Acute respiratory infections, adverse factors of the production environment and microclimate.
Prolonged inhalation of dust causes primary damage to the mucous membrane of the bronchi, the development of its catarrhal state with a violation of the secretory, cleansing and protective function of the bronchi. Excessive secretion of mucus as a result of perfusion and hyperplasia of secretory elements – mucous and serous membranes of bronchial glands, goblet cells – leads to a violation of mucociliary transport, development of mucociliary insufficiency. At the same time, the increased production of bronchial secretion and the violation of its rheological properties with the ineffectiveness of the tile reflex contribute to the accumulation of contents in the lumen of the bronchi. The latter creates conditions for the reproduction of microorganisms, the development of secondary bronchial infection. It is known that in most cases of chronic bronchitis of dust etiology, there is a broncho-obstructive syndrome, which is accompanied by a decrease in the non-specific reactivity of the body in the form of suppression of the phagocytic activity of alveolar macrophages and neutrophils and secondary immunological insufficiency, which causes the chronic, continuously relapsing course of this disease.
Among all pathogenic factors of bronchial obstruction, bronchial spasm plays the most important role. Mechanisms of bronchial spasm are very complex. It is probably based on the hyperactivity of the bronchial trunk, caused both by non-specific changes in the reactivity of the bronchi due to irrigation with pollutants, and by allergic reactions in response to sensitization (organic dust, infectious agents). In the future, dust bronchitis with bronchospastic syndrome can be complicated by a pre-asthmatic state in the transition to bronchial asthma.
However, regardless of the common pathogenetic mechanisms in the development of chronic bronchitis in people living in different areas. The chemical composition, amount, dispersion of dust and individual characteristics of the organism are important.
According to modern data, allergic diseases, which are characterized by significant nosological diversity, are an indicator of the connection between environmental pollution and the occurrence of pathological changes in children.
The heterogeneity of environmental problems reflected by the indicators of the prevalence of allergic diseases, such as the presence of heavy metals, air dustiness, the prevalence of allergic diseases does not prevent the study of individual multifactorial eco-medical systems, subsystems, etc. One of them is a multifactorial system of formation of allergic disease, the formation of which takes place in early childhood mainly under the influence of a complex of external factors. It is the ecological aspect of the formation of allergies that has recently been given the main role.
The study, analysis and monitoring of areas with different degrees of allergy among the children’s population is a necessary basis for finding real ways to develop models of resistance to allergies, reducing the prevalence of symptomatic manifestations and the actual incidence of allergies, as well as the adequacy to the situation of the organization of primary and secondary health care for the children’s population.
Translated by AI
