Harmful substances contained in vehicle exhaust emissions have an extremely negative impact on human health. Oxides of carbon and nitrogen, hydrocarbons, compounds containing sulfur - this is the dangerous “cocktail” that we consume every day on the streets of our city.

The influence of road transport on the environmental situation in our country has reached a critical point; air and environmental pollution indicators exceed all acceptable indicators of world norms and standards. Therefore, the problem of reducing the negative impact on the environment of road transport at all stages of its life cycle is relevant. Analysis of statistical data and assessments of the negative impact of motor transport on the environment and population shows that the total amount of pollutant emissions into the atmosphere in the CIS countries annually amounts to almost 21.2 million tons, in particular, 19.2 million tons (90%) - from road transport, and 2.0 million tons from other emissions.

Motorization brings people a wide variety of benefits, but at the same time its development is accompanied by extremely negative phenomena. Highways have become the site of death and injury of millions of people; vehicles are one of the most active polluters of atmospheric air, water and soil, noise and vibration pollution. The road network passes through valuable agricultural land; flora and fauna suffer from the harmful effects of road transport.

The construction of new and reconstruction of existing highways negatively affects the natural environment, in particular, the land fund. The destruction of the natural landscape is affected by road dust, heavy components of vehicle exhaust gases, and wear products of the vehicles themselves. Therefore, the issue of the emergence of factors of negative impact on land resources and areas of their distribution during the construction of new and reconstruction of existing roads requires a more detailed study.

The results of the interaction of highways with the environment depend on the intensity of traffic, the characteristics of vehicles, the location and size of the road, its transport and operational qualities and the operating system. In the environmental aspect, a highway is considered not only as an engineering structure, but as an elongated enterprise that carries out transport work and interacts with the environment.

The influence of roads and vehicles on the environment is a complex system of interaction of various factors that can be divided into two groups: road and transport. Road factors include: allocations of land for the construction of a highway, violation of the unity and integrity of the natural complex, changes in the natural topography of the area during construction. Transport factors include: noise and air pollution resulting from the movement of motor vehicles, pollution of the strip adjacent to the road with harmful substances contained in the exhaust gases of cars. The highway disrupts the main balances existing in nature: biological, water, gravitational, radiation.

Everyday operation of cars involves the use of operating materials, petroleum products, natural gas, atmospheric air, and is accompanied by all this negative processes, namely:

• air pollution;
• water pollution;
• land and soil pollution;
• noise, electromagnetic and vibration influences;
• release of unpleasant odors into the atmosphere;
• release of toxic waste;
• thermal pollution.

The impact of road transport on the environment is manifested:

• while cars are moving;
• during maintenance;
• during the functioning of the infrastructure, which ensures its operation.

To ensure environmentally sustainable development of the environmental safety of road transport, it is necessary to effectively use existing infrastructure, reduce transportation needs and be prepared to transition to the use of environmentally friendly vehicles, and when developing the designs of new automotive vehicles, it is necessary to consider the environmental priorities of the vehicle, taking into account its full life cycle.

The priority areas for improving the environmental safety of a car at all stages of its life cycle are:

• various ways to reduce emissions of toxic components into the environment;
• installation on units and parts that are subject to the most rapid wear of special indicators that provide information about the need to replace them;
• avoiding uncontrolled disposal of hazardous waste;
• design and manufacture of new vehicles capable of quick disassembly, subsequent use of used, serviceable mechanisms and assemblies and their disposal;
• constant increase in the amount of environmentally friendly materials in production and control over the use of materials with harmful substances in the construction of cars;
• at all stages of the vehicle’s life cycle, the use of harmful materials and special liquids should be minimal;
• timely maintenance and precise adjustment of the ignition and power systems of internal combustion engines;
• reducing the harmful effects of toxic substances on the environment during operation through the introduction of the latest systems for neutralizing harmful emissions;
• widespread use of liquefied natural gas, alternative fuels, new vehicles such as electric vehicles;
• introduction of various additives and neutralizers into the fuel composition, which ensure its smokeless combustion;
• use of the latest ignition systems that promote complete combustion of fuel;
• improving the ecology of large cities by complying with the requirements of environmental legislation, prohibiting the construction of parking lots in city centers, controlling the construction of gas stations within the city, building bypass roads, stopping the mass cutting of trees and parklands under the pretext of “sanitary” felling, and encouraging environmentally friendly transport.

To comprehensively take into account the negative impact of highways on the environment, it is necessary to work on creating a system of objective scales with values ​​that include all aspects of the protection of territories.

An analysis of the impact of transport products on the environment showed that chemical pollution has a huge negative impact on human health and the climate. Emissions into the air lead to disruptions in the functioning of the human respiratory, cardiovascular and nervous systems.

All this speaks to the need to take measures to improve the environmental situation in cities, in particular through the application of policies for the sustainable development of transport systems.

Bibliography:

1. Grigorieva S.V. Assessing the influence of motor transport on the socio-economic development of the region // Innovative development of the economy. 2012. No. 6 (12). pp. 20-24.
2. Dryabzhinsky O.E., Gaponenko A.V. Prospects for the development of motor transport under the influence of economic and environmental factors // Scientific and methodological electronic journal Concept. 2016. T. 11. pp. 2776-2780.
3. Nedikova E.V., Zotova K.Yu. Features of the influence of highways and vehicles on the environment // Economics and ecology of territorial entities. 2016. No. 2. P. 82-85.
4. Sitdikova A.A., Svyatova N.V., Tsareva I.V. Analysis of the influence of vehicle emissions in a large industrial city on the state of atmospheric air pollution // Modern problems of science and education. 2015. No. 3. P. 591.

There are horse-drawn, automobile, agricultural (tractors and combines), railway, water, air and pipeline transport. The length of the world's main paved roads exceeds 12 million km, air lines - 5.6 million km, railways - 1.5 million km, main pipelines - about 1.1 million km, inland waterways - more 600 thousand km. Sea lines are many millions of kilometers long.

All vehicles with autonomous prime movers pollute the atmosphere to some extent from chemical compounds contained in exhaust gases. On average, the contribution of individual types of vehicles to air pollution is as follows:

automobile – 85%;

sea ​​and river - 5.3%;

air - 3.7%;

railway - 3.5%;

agricultural - 2.5%.

In many large cities, such as Berlin, Mexico City, Tokyo, Moscow, St. Petersburg, Kiev, air pollution from automobile exhaust amounts, according to various estimates, from 80 to 95% of all pollution.

As for air pollution by other types of transport, the problem here is less acute, since vehicles of these types are not concentrated directly in cities. Thus, in the largest railway junctions, all traffic has been switched to electric traction and diesel locomotives are used only for shunting work. River and sea ports, as a rule, are located outside the residential areas of cities, and ship traffic in port areas is practically insignificant. Airports, as a rule, are located 20-40 km from cities. In addition, the large open spaces above airfields, as well as above river and sea ports, do not create the danger of high concentrations of toxic impurities emitted by engines. Along with environmental pollution by harmful emissions, the physical impact on the atmosphere in the form of the formation of anthropogenic physical fields (increased noise, infrasound, electromagnetic radiation) should be noted. Of these factors, the most widespread impact is caused by increased noise. Transport is the main source of acoustic pollution of the environment. In large cities, the noise level reaches 70-75 dBA, which is several times higher than permissible standards.

10.2. Automobile transport

The total global vehicle fleet numbers more than 800 million units, of which 83-85% are passenger cars, and 15-17% are trucks and buses. If the growth trends in vehicle production remain unchanged, then by 2015 the number of vehicles may increase to 1.5 billion units. Motor transport, on the one hand, consumes oxygen from the atmosphere, and on the other hand, it emits exhaust gases, crankcase gases and hydrocarbons into it due to their evaporation from fuel tanks and leaky fuel supply systems. A car has a negative impact on almost all components of the biosphere: the atmosphere, water resources, land resources, lithosphere and humans. An assessment of environmental hazards through resource and energy variables of the entire life cycle of a car from the moment of extraction of mineral resources needed for its production to waste recycling after the end of its service showed that the environmental “cost” of a 1-ton car, in which approximately 2/3 of the mass is metal, equal to 15 to 18 tons of solid and 7 to 8 tons of liquid waste disposed in the environment.

Exhausts from vehicles spread directly onto city streets along roads, having a direct harmful effect on pedestrians, residents of nearby buildings and vegetation. It was revealed that zones exceeding the maximum permissible concentrations for nitrogen dioxide and carbon monoxide cover up to 90% of the urban area.

A car is the most active consumer of air oxygen. If a person consumes up to 20 kg (15.5 m3) of air per day and up to 7.5 tons per year, then a modern car consumes about 12 m3 of air or about 250 liters of oxygen in oxygen equivalent to burn 1 kg of gasoline. Thus, all US road transport consumes 2 times more oxygen than nature regenerates throughout its territory.

Thus, in large cities, road transport absorbs oxygen tens of times more than their entire population. Studies conducted on Moscow highways have shown that in calm, windless weather and low atmospheric pressure on busy highways, the combustion of oxygen in the air often increases to 15% of its total volume.

It is known that when the oxygen concentration in the air is below 17%, people develop symptoms of malaise, at 12% or less there is a danger to life, at a concentration below 11%, loss of consciousness occurs, and at 6%, breathing stops. On the other hand, on these highways there is not only little oxygen, but the air is also saturated with harmful substances from automobile exhaust. A special feature of automobile emissions is that they pollute the air at the height of human growth, and people breathe these emissions.

Composition of vehicle emissions includes about 200 chemical compounds, which, depending on the characteristics of their effects on the human body, are divided into 7 groups.

IN 1st group includes chemical compounds contained in the natural composition of atmospheric air: water (in the form of steam), hydrogen, nitrogen, oxygen and carbon dioxide. Motor vehicles emit such a huge amount of steam into the atmosphere that in Europe and the European part of Russia it exceeds the evaporation mass of all reservoirs and rivers. Because of this, cloudiness increases, and the number of sunny days decreases noticeably. Gray, sunless days, unheated soil, constantly increased air humidity - all this contributes to the growth of viral diseases and a decrease in agricultural yields.

In 2nd group carbon monoxide is included (maximum permissible concentration 20 mg/m3; 4 cells). It is a colorless gas, tasteless and odorless, very slightly soluble in water. Inhaled by a person, it combines with hemoglobin in the blood and suppresses its ability to supply the body's tissues with oxygen. As a result, oxygen starvation occurs in the body and disturbances in the activity of the central nervous system occur. The effects of exposure depend on the concentration of carbon monoxide in the air; Thus, at a concentration of 0.05%, after 1 hour signs of mild poisoning appear, and at 1%, loss of consciousness occurs after several breaths.

IN 3rd group includes nitrogen oxide (MPC 5 mg/m 3, 3 cells) - a colorless gas and nitrogen dioxide (MPC 2 mg/m 3, 3 cells) - a reddish-brown gas with a characteristic odor. These gases are impurities that contribute to the formation of smog. Once in the human body, they, interacting with moisture, form nitrous and nitric acids (MPC 2 mg/m 3, 3 cells). The consequences of exposure depend on their concentration in the air, so, at a concentration of 0.0013%, slight irritation of the mucous membranes of the eyes and nose occurs, at 0.002% - the formation of metahemoglobin, at 0.008% - pulmonary edema.

IN 4th group includes hydrocarbons. The most dangerous of them is 3,4-benzo(a)pyrene (MPC 0.00015 mg/m 3, 1 class) - a powerful carcinogen. Under normal conditions, this compound is yellow needle-shaped crystals, poorly soluble in water and well soluble in organic solvents. In human serum, the solubility of benzo(a)pyrene reaches 50 mg/ml.

IN 5th group includes aldehydes. The most dangerous for humans are acrolein and formaldehyde. Acrolein is an aldehyde of acrylic acid (MPC 0.2 mg/m 3, 2 cells), colorless, with the smell of burnt fat and a very volatile liquid that dissolves well in water. A concentration of 0.00016% is the threshold for odor perception, at 0.002% the odor is difficult to tolerate, at 0.005% it is intolerable, and at 0.014 death occurs after 10 minutes. Formaldehyde (maximum concentration limit 0.5 mg/m 3, 2 cells) is a colorless gas with a pungent odor, easily soluble in water.

At a concentration of 0.007% it causes mild irritation of the mucous membranes of the eyes and nose, as well as the upper respiratory organs; at a concentration of 0.018% the breathing process is complicated.

IN 6th group includes soot (maximum permissible concentration 4 mg/m 3, 3 cells), which has an irritating effect on the respiratory system. Research conducted in the USA revealed that 50-60 thousand people die annually from soot air pollution. It was found that soot particles actively adsorb benz(a)pyrene on its surface, as a result of which the health of children suffering from respiratory diseases, people with asthma, bronchitis, pneumonia, as well as the elderly, sharply worsens.

IN 7th group includes lead and its compounds. Tetraethyl lead is added to gasoline as an anti-knock additive (MPC 0.005 mg/m 3, 1 class). Therefore, about 80% of lead and its compounds that pollute the air enter it when leaded gasoline is used. Lead and its compounds reduce the activity of enzymes and disrupt metabolism in the human body, and also have a cumulative effect, i.e. ability to accumulate in the body. Lead compounds are especially harmful to the intellectual abilities of children. Up to 40% of the compounds that enter it remain in the child’s body. In the USA, the use of leaded gasoline is prohibited everywhere, and in Russia - in Moscow, St. Petersburg and a number of other large cities.

Today, the internal combustion engine

installed on a vehicle, is recognized as one of the main sources

environmental pollution. What makes the situation worse is the fact that

the car is in close proximity to people, and this

enhances its negative impact on humans, flora and

fauna. According to the World Health Organization, it is

the car is the cause of more than 80 thousand annual deaths

Europeans. Lung cancer, chronic bronchitis, asthma, allergies

diseases - all this is directly related to emissions

vehicle exhaust gases. According to the data

domestic and foreign research, transport and road

complex, which includes cars, airplanes,

diesel locomotives, ships, agricultural machinery and road equipment, is

one of the main air pollutants.

Thus, the main share in environmental pollution

environment is contributed by road transport, or rather engines

internal combustion engines installed on cars.

Exhaust gases (EG) are formed as a result of combustion

fuel during engine operation. Negative impact of exhaust gas on

environment due to the chemical effects of these

substances on the cells of plants and living organisms, as well as on

organisms and cause harm to the internal organs and cells of these

organisms.

In addition to exhaust gases, negative impact on the environment

crankcase gases and fuel vapors from the internal combustion engine.

Fuel evaporation often occurs from the fuel system

engine due to leaky connections or careless

operation.

The processes that drive a car are based on

combustion of fuel, impossible without oxygen.

Of course, emissions from internal combustion engine exhaust gases, fuel vapors and

absorption of oxygen from the atmosphere negatively affects

general environmental situation and lead to the emergence

various diseases in people.

4 Toxicity of exhaust gases from automobile engines. Reasons for the formation of toxic components.

The toxicity of internal combustion engines refers to the negative impact

impact on the environment - plants, animals, people and

buildings with harmful substances contained in waste

gases (OG) [

Traditional fuels for internal combustion engines are complex

mixture of hydrocarbons: saturated, unsaturated, aromatic,

cyclic, etc. Fuel almost always contains sulfur and traces

metals that enter it from oil and are not fully

are removed during oil refining and fuel production.

As a result of ideal fuel combustion in the internal combustion engine, there should be

Only carbon dioxide - CO2 and water - H2O are formed. However

poor-quality preparation of the air-fuel mixture and

features of the organization of the combustion process in an internal combustion engine lead to

the formation of toxic substances that are emitted from the exhaust gas.

Exhaust gases from internal combustion engines consist of 99.0-99.9% products of complete

combustion of fuel (CO2 and H2O), as well as from unused

oxygen and nitrogen. But 1% of exhaust gases contain the most

toxic substances that determine the negative impact

OG on the environment. Composition of internal combustion engine exhaust gases

depends on the type and quality of the fuel used, as well as on the type

organization of the work process. Therefore, the composition of OG differs

different types of engines and is designated within a wide range.

Introduction

Impact of motor transport on the environment

Chemical impact of vehicles on the environment and methods for its prevention

1 Air pollution

2 Lithosphere pollution

3 Hydrosphere pollution

Physical impact of motor transport and methods of its prevention

Mechanical impact of vehicles on the environment and methods for its prevention

Conclusion

List of used literature

motor transport pollution environment

Introduction

The problem of reliable environmental protection, rational and maximum use of natural resources is one of the most pressing among global problems.

The transport complex, in particular in Russia, which includes road, sea, inland waterway, rail and air transport, is one of the largest polluters of atmospheric air. Its impact on the environment is expressed mainly in the emissions of toxicants into the atmosphere from the exhaust gases of transport engines and harmful substances from stationary sources, as well as in the pollution of surface water bodies, the formation of solid waste and the impact of transport noise.

The main sources of environmental pollution and consumers of energy resources include road transport and the infrastructure of the road transport complex.

Pollutant emissions into the atmosphere from cars are more than an order of magnitude greater than emissions from railway vehicles. Next come (in descending order) air transport, sea transport and inland water transport. The non-compliance of vehicles with environmental requirements, the continuing increase in traffic flows, the unsatisfactory condition of roads - all this leads to a constant deterioration of the environmental situation.
In addition to poisoning with harmful emissions of air gases, road transport pollutes large areas with fuel and lubricants and is a powerful source of increased noise and electromagnetic radiation.

The overall picture of environmental pollution from road transport continues to worsen.
In recent decades, due to the rapid development of road transport, the problems of its impact on the environment have significantly worsened. Cars burn huge amounts of petroleum products, simultaneously causing significant harm to the environment, mainly the atmosphere.

Every year the number of vehicles increases, and, consequently, the content of harmful substances in the atmospheric air increases. The constant increase in the number of cars has a certain negative impact on the environment and human health.

1. Impact of vehicles on the environment

Nature is an integral system with many balanced connections. Violation of these connections leads to changes in the cycles of substances and energy established in nature. Modern society involves in production and consumption an amount of matter and energy that is hundreds of times greater than human biological needs, which is the main cause of the modern environmental crisis.

Today, human production activity is associated with the use of a variety of natural resources, including most chemical elements. The increased anthropogenic impact on the natural environment has given rise to a number of environmental problems. The most acute ones are related to the state of the atmosphere, hydrosphere and lithosphere.

One of the problems of urbanized areas is the change in environmental properties under the influence of vehicles. Types of impact of motor transport on the environment are presented in Fig. 1.

Scheme 1. Impact of motor transport on the environment

2. Chemical impact of vehicles on the environment and methods for its prevention

2.1 Air pollution

Motor transport in a number of regions accounts for over 50% of the total emissions of pollutants into the atmosphere. Atmospheric pollution from mobile sources of vehicles occurs to a greater extent with exhaust gases through the exhaust system of a car engine, and also, to a lesser extent, with crankcase gases.

Each car emits about 200 different components into the atmosphere with exhaust gases. The main types of pollutant emissions from mobile sources, their impact on the human body and the environment are presented in the table.

Harmful substances	Consequences of exposure to the human body and the environment
Carbon monoxide CO	Carbon monoxide is a product of incomplete combustion of fuel; it burns with a blue flame in air to form carbon dioxide. In the combustion chamber of an engine, CO is formed due to poor atomization of fuel, as a result of cold-flame reactions, during combustion of fuel with a lack of oxygen. In subsequent combustion after ignition, carbon monoxide may burn in the presence of oxygen to form dioxide. In this case, the process of CO burnout continues in the exhaust pipeline.
	Appears in exhaust gases when tetraethyl lead is used - an anti-knock additive for gasoline. Lead can accumulate in the body, entering it through the respiratory tract, with food and through the skin. Affects the central nervous system and hematopoietic organs. It causes a decrease in mental abilities in children, is deposited in bones and other tissues, and is therefore dangerous for a long time.
Nitrogen oxides NO, NO2, N2O4	Nitrogen oxides pose a danger to plant leaves. It has been established that their direct toxic effect on plants occurs at NOx concentrations in the air within the range of 0.5 - 6.0 mg/m3. Nitric acid is highly corrosive to carbon steels. The amount of nitrogen oxide emissions is significantly influenced by the temperature in the combustion chamber. Early fuel injection or high compression pressures in the combustion chamber also contribute to the formation of NOx. Exposure to nitrogen oxides in humans leads to dysfunction of the lungs and bronchi. Children and people with cardiovascular diseases are more susceptible to the effects of nitrogen oxides.
Hydrocarbons	They have an unpleasant odor. As a result of photochemical reactions of hydrocarbons with nitrogen oxides, smog is formed. Lead to an increase in pulmonary and bronchial diseases
Sulfur compounds	In a free atmosphere, sulfur dioxide (SO2) after some time is oxidized to sulfur dioxide (SO3) or interacts with other compounds, in particular hydrocarbons. The oxidation of sulfur dioxide to sulfur dioxide occurs in a free atmosphere during photochemical and catalytic reactions. In both cases, the end product is an aerosol or solution of sulfuric acid in rainwater. In dry air, oxidation of sulfur dioxide occurs extremely slowly. In the dark, SO2 oxidation is not observed. In the presence of nitrogen oxides in the air, the rate of oxidation of sulfur dioxide increases regardless of air humidity. They have an irritating effect on the mucous membranes of the human throat, nose and eyes.
Dust particles	Irritates the respiratory tract.

Crankcase gases are a mixture of part of the exhaust gases that penetrated through the leaks of the piston rings into the engine crankcase with engine oil vapors. The amount of crankcase gases in the engine increases with wear. In addition, it depends on driving conditions and engine operating mode.

Gasoline vapors in a car occur when the engine is running and when it is not running. They arise not only in mobile sources, but also in stationary ones, which, first of all, include gas stations. They receive, store and sell gasoline and other petroleum products in large quantities. This is a serious channel for environmental pollution, both as a result of fuel evaporation and spills.

Highways are one of the sources of dust formation in the ground air layer. When cars move, abrasion occurs on road surfaces and car tires, the wear products of which are mixed with solid particles of exhaust gases. Added to this is dirt brought onto the roadway from the soil layer adjacent to the road. The chemical composition and amount of dust depend on the road surface materials.

It is difficult to imagine the modern world without a large number of vehicles, therefore, in order to maintain the ecological and economic balance, it is advisable to develop a system of measures aimed at improving the quality of atmospheric air

Scheme 2. System of measures aimed at improving air quality

Only the comprehensive implementation of technological, planning, organizational and technical measures can lead to an improvement in the quality of the environment in the city.

2.2 Lithosphere pollution

Substances that enter the atmospheric air with exhaust gases and then settle on the soil. Soils have the ability to retain and retain both atmospheric and groundwater, which enrich the soil with chemical compounds and thereby influence the formation of one or another type of soil. It is determined that soil makes a finite number of elements infinite. This happens because the soil is involved in a number of biosphere cyclic processes. Elements found in soil, water, and soil air can come into virtually unlimited number of contacts and form an infinite number of bonds.

Soil is an integral part of almost all biosphere cycles of substances. Metals and their compounds act as the main soil pollutants. Soil contamination with lead is widespread and dangerous. Lead compounds are used as additives in gasoline, so motor vehicles are a serious source of lead pollution. Lead is especially high in soils along major highways.

When 1 liter of leaded gasoline is burned, 200 to 500 mg of lead is released. This highly active, dispersed lead enriches the soil along roads.

As long as heavy metals are firmly bound to soil constituents and are difficult to access, their negative impact on the soil and the environment will be negligible. However, if soil conditions allow heavy metals to pass into the soil solution, there is a direct danger of soil contamination, and there is a possibility of their penetration into plants, as well as into the human body and animals that consume these plants. The danger of soil and plant contamination depends on: the type of plant; forms of chemical compounds in the soil; the presence of elements that counteract the influence of heavy metals and substances that form complex compounds with them; from adsorption and desorption processes; the amount of available forms of these metals in the soil and soil and climatic conditions. Consequently, the negative impact of heavy metals depends essentially on their mobility, i.e. solubility.

Self-purification of soils is usually a slow process. Toxic substances accumulate, which contributes to a gradual change in the chemical composition of soils, disrupting the unity of the geochemical environment and living organisms. From the soil, toxic substances can enter the bodies of animals and people and cause severe illness and death.

The size of the zone of influence of motor transport on ecosystems varies greatly. The width of roadside anomalies of lead content in the soil can reach 100-150m. Forest strips along roads retain lead flows from vehicles in their crowns. In urban conditions, the extent of lead contamination is determined by building conditions and the structure of green spaces. In dry weather, lead accumulates on the surface of plants, but after heavy rains, a significant part of it (up to 45%) is washed off.

In order to reduce lead pollution, it is necessary to reduce the use of leaded gasoline, because This gasoline is the source of lead emissions into the atmosphere. It is also necessary to create a number of installations that would retain lead, i.e. the amount of lead deposited in these installations. Any type of vegetation is a natural installation.

2.3 Hydrosphere pollution

Pollution of water bodies is understood as a decrease in their biosphere functions and ecological significance as a result of the entry of harmful substances into them. Water pollution from transport waste manifests itself in changes in physical and organoleptic properties (impaired transparency, color, odors, taste), an increase in the content of sulfates, chlorides, nitrates, toxic heavy metals, a reduction in air oxygen dissolved in water, and the appearance of radioactive elements. It has been established that more than 400 types of substances emitted during the operation of vehicles can cause water pollution. If the permissible norm is exceeded by at least one of three hazard indicators: sanitary-toxicological, general sanitary or organoleptic, the water is considered contaminated.

Intensive pollution of the hydrosphere by motor vehicles occurs due to the following factors. One of them is the lack of garages for thousands of individual cars stored in open areas in the courtyards of residential buildings. The situation is further aggravated by the fact that the network of repair services for personal cars is not sufficiently developed. This forces their owners to carry out repairs and maintenance on their own, which they do, of course, without taking into account the environmental consequences. An example would be private car washes or unauthorized car washing sites: due to the lack of washing stations, this operation is often carried out on the banks of a river, lake or pond.

Meanwhile, motorists are increasingly using synthetic detergents, which pose a certain danger to water bodies. Storm wastewater from the surface of highways, gas station sites, and from the territory of motor transport and auto repair enterprises is also a powerful source of pollution of water basins in urban areas with petroleum products, phenols and easily oxidized organic substances. The entry of heavy metals and toxic substances with wastewater sharply limits the consumption and use of water resources.

To reduce pollution of surface waters of open reservoirs, it is necessary to create a drainless water supply system in areas used for washing cars, as well as the construction of local treatment facilities with subsequent dilution of the residual amount of pollutants. Practice has shown that existing technological processes for wastewater treatment contribute to the removal of 95-99% of organic substances and 40-99% of suspended solids. However, they practically do not reduce the content of salts in them, of which the most dangerous are toxic substances, including carcinogenic ones, which include one of the most toxic - tetroethyl lead.

3. Physical impact of motor transport and methods of its prevention

The level of street noise is determined by the intensity, speed and nature (composition) of traffic flow. In addition, it depends on planning decisions (longitudinal and transverse profile of streets, height and density of buildings) and such landscaping elements as roadway coverage and the presence of green spaces. Each of these factors can change the level of transport noise by up to 10 dB.

In an industrial city there is usually a high percentage of freight transport on highways. An increase in the overall traffic flow of trucks, especially heavy-duty ones with diesel engines, leads to an increase in noise levels. The noise generated on the roadway of the highway extends not only to the area adjacent to the highway, but also deep into residential areas. Noise levels measured in living rooms with open windows facing the indicated highways are only 10-15 dB lower.

The acoustic characteristics of traffic flow are determined by vehicle noise indicators. The noise produced by individual transport crews depends on many factors: engine power and operating mode, technical condition of the crew, quality of the road surface, and speed. Significant noise is caused by sudden braking of the car when driving at high speed.

Recently, the average noise level produced by transport has increased by 12-14 dB. That is why the problem of combating noise in the city is becoming increasingly acute.

In conditions of strong city noise, the auditory analyzer is constantly stressed. The damage that loud noise causes to hearing depends on the spectrum of sound vibrations and the nature of their changes. The risk of possible noise-induced hearing loss largely depends on the individual.

Noise in big cities shortens a person's life expectancy, and can also cause nervous exhaustion, mental depression, autonomic neurosis, peptic ulcers, disorders of the endocrine and cardiovascular systems, and also significantly disrupts sleep.

To protect people from the harmful effects of urban noise, it is necessary to regulate its intensity, spectral composition, duration of action and other parameters. During hygienic standardization, a noise level is set as acceptable, the influence of which for a long time does not cause changes in the entire complex of physiological indicators, reflecting the reactions of the body systems most sensitive to noise.

Currently, noise for urban development conditions is standardized in accordance with the Sanitary Standards for Permissible Noise in Residential and Public Buildings and on Residential Development Territories (No. 3077-84) and Building Codes and Regulations II.12-77 “Protection from Noise.” Sanitary standards are mandatory for all ministries, departments and organizations designing, constructing and operating housing and public buildings, developing planning and development projects for cities, microdistricts, residential buildings, neighborhoods, communications, etc., as well as for organizations designing, manufacturing and operating vehicles, technological and engineering equipment of buildings and household appliances.

GOST 19358-85 “External and internal noise of vehicles. Permissible levels and methods of measurement" establishes noise characteristics, methods of their measurement and permissible noise levels of cars (motorcycles) of all samples accepted for state, interdepartmental, departmental and periodic control tests.

Reducing urban noise can be achieved primarily by reducing vehicle noise.

Urban planning measures to protect the population from noise include: increasing the distance between the noise source and the protected object; the use of acoustically opaque screens (slopes, walls and screen buildings), special noise protection strips for landscaping; the use of various planning techniques, rational placement of microdistricts. In addition, urban planning measures include rational development of main streets, maximum landscaping of microdistricts and dividing strips, use of terrain, etc.

4. Mechanical impact of vehicles on the environment and methods for its prevention

Significant areas of land are being alienated for roads. Thus, the construction of 1 km of a modern highway requires up to 10-12 hectares of area, including fertile land. Soil erosion occurs quite quickly, and it takes about 100 years to recreate a fertile layer 1 cm deep. Soil conservation is served by such main directions in the development of transport as the allocation of less agriculturally valuable lands for transport facilities; preservation of traditional hydrological regimes in the area of ​​transport facilities; reduction (better cessation) of soil pollution by harmful components of vehicles.

Abroad and in our country, they are gaining experience in the economic use of land with the development of motor transport, for example, large underground garages are being built in cities. Many new underground structures are planned.

The extraction from the ground of large quantities of metals necessary for the production of vehicles leads to a disruption in the equalization of the energy balance, as a result of which, when this balance is equalized, the consumption or release of energy into space occurs mainly through faults in the lithosphere, and not through ore deposits, as this happened earlier, which began to lead to local earthquakes and local fires.

Road construction affects the hydrological regime of the area, which leads to changes in the composition of biogeocenoses; and deforestation, in turn, leads to changes in floristic composition.

Conclusion

Nature conservation is the task of our century, a problem that has become social. There are several most important reasons for Russia's lag in the environmental sphere:

low culture of car operation. The number of faulty cars still in use is quite high;

lack of strict legal requirements for the environmental qualities of cars. In the absence of sufficiently stringent emission requirements, the consumer is not interested in buying more environmentally friendly, but at the same time more expensive cars, and the manufacturer is not inclined to produce them;

unprepared infrastructure for operating vehicles equipped in accordance with modern environmental requirements;

Unlike European countries, the introduction of neutralizers in our country is still difficult.

In recent years, the situation has begun to change for the better. Although the implementation of strict environmental regulations is happening with a delay of 10 years, it is important that it has begun.

The main ways to reduce environmental damage from transport are as follows:

) optimization of urban transport;

) development of alternative energy sources;

) afterburning and purification of organic fuel;

) creation (modification) of engines using alternative fuels;

) noise protection;

) economic initiatives for vehicle fleet and traffic management

List of used literature

1. Gasoline, make room // Factor. No. 3. 2011. - pp. 40-41.

2. Golubev I.R., Novikov Yu.V. Environment and transport. - M.: Transport, 2007

Guryanov D.I. Environmentally friendly transport: directions of development

// Engineer, technologist, worker. No. 2. 2011. - pp. 12-14.

4. Zhukov S. Natural gas - motor fuel of the XXI century //

Industry today. No. 2. 2011. - P. 12.

5. Kirillov N.G. But the problem is still there - the problem of greening

motor transport of St. Petersburg // Industry Today.

No. 11. 2011. - P.13.

6. Krinitsky E. The environmental friendliness of vehicles should be determined

Federal Law // Automobile transport. No. 9. 2010. - pp. 34-37.

7. Lukanin V.N., Gudtsov V.N., Bocharov N.F. Reducing vehicle noise. - M.: Mechanical Engineering, 2011. - 289 p.

8. Naumov Ya. G. Ecology of Russia. - M. 2009.

Road transport is the most aggressive in relation to the environment compared to other modes of transport. It is a powerful source of chemical (supplies a huge amount of toxic substances into the environment), noise and mechanical pollution. It should be emphasized that with the increase in the vehicle fleet, the level of harmful effects of vehicles on the environment increases rapidly. Thus, if in the early 70s, hygienist scientists determined the share of pollution introduced into the atmosphere by road transport to be on average 13%, now it has already reached 50% and continues to grow. And for cities and industrial centers, the share of motor transport in the total volume of pollution is much higher and reaches 70% or more, which creates a serious environmental problem that accompanies urbanization.

There are several sources of toxic substances in cars, the main three of which are:

• exhaust gases
• crankcase gases
• fuel fumes

Rice. Sources of toxic emissions

The largest share of chemical pollution of the environment by road transport comes from exhaust gases from internal combustion engines.

Theoretically, it is assumed that with complete combustion of fuel, carbon dioxide and water vapor are formed as a result of the interaction of carbon and hydrogen (included in the fuel) with oxygen in the air. The oxidation reactions have the form:

C+O2=CO2,
2H2+O2=2H2.

In practice, due to the physical and mechanical processes in the engine cylinders, the actual composition of the exhaust gases is very complex and includes more than 200 components, a significant part of which are toxic.

Table. Approximate composition of exhaust gases from automobile engines

Components	Dimension	Component concentration limits Gasoline, with spark. ignition Diesel
		Gasoline	Diesel
Oxygen, O2
Water vapor, H2O			0,5…10,0
Carbon dioxide, CO2
Hydrocarbons, CH (total)
Carbon monoxide, CO
Nitric oxide, NOx
Aldehydes
Sulfur oxides (total)
Benz(a)pyrene
Lead compounds

Using the example of passenger cars without neutralization, the composition of engine exhaust gases can be presented in the form of a diagram.

Rice. Components of exhaust gases without neutralization

As can be seen from the table and figure, the composition of the exhaust gases of the types of engines under consideration differs significantly, primarily in the concentration of products of incomplete combustion - carbon monoxide, hydrocarbons, nitrogen oxides and soot.

Toxic components of exhaust gases include:

• carbon monoxide
• hydrocarbons
• nitrogen oxides
• sulfur oxides
• aldehydes
• benz(a)pyrene
• lead compounds

The difference in the composition of the exhaust gases of gasoline and diesel engines is explained by the large excess air coefficient α (the ratio of the actual amount of air entering the engine cylinders to the amount of air theoretically required for the combustion of 1 kg of fuel) in diesel engines and better fuel atomization (fuel injection). In addition, in a gasoline carburetor engine, the mixture for different cylinders is not the same: for cylinders located closer to the carburetor it is rich, and for cylinders located further from it it is poorer, which is a disadvantage of gasoline carburetor engines. Part of the air-fuel mixture in carburetor engines enters the cylinders not in a vapor state, but in the form of a film, which also increases the content of toxic substances due to poor fuel combustion. This disadvantage is not typical for gasoline engines with fuel injection, since the fuel is supplied directly to the intake valves.

The reason for the formation of carbon monoxide and partially hydrocarbons is the incomplete combustion of carbon (the mass fraction of which in gasoline reaches 85%) due to an insufficient amount of oxygen. Therefore, the concentrations of carbon monoxide and hydrocarbons in the exhaust gases increase with enrichment of the mixture (α 1, the probability of these transformations in the flame front is low and the exhaust gases contain less CO, but there are additional sources of its appearance in the cylinders:

• low-temperature flame sections of the fuel ignition stage
• drops of fuel entering the chamber at the late stages of injection and burning in a diffusion flame with a lack of oxygen
• soot particles formed during the propagation of a turbulent flame along a heterogeneous charge, in which, with a general excess of oxygen, zones with oxygen deficiency can be created and reactions such as:

2C+O2 → 2СО.

Carbon dioxide CO2 is not toxic, but a harmful substance due to the recorded increase in its concentration in the planet’s atmosphere and its impact on climate change. The main share of CO formed in the combustion chamber is oxidized to CO2 without leaving the chamber, because the measured volume fraction of carbon dioxide in the exhaust gases is 10-15%, i.e. 300...450 times more than in atmospheric air. The greatest contribution to the formation of CO2 is made by the irreversible reaction:

CO + OH → CO2 + H

The oxidation of CO into CO2 occurs in the exhaust pipe, as well as in exhaust gas neutralizers, which are installed on modern cars for the forced oxidation of CO and unburned hydrocarbons to CO2 due to the need to meet toxicity standards.

Hydrocarbons

Hydrocarbons - numerous compounds of various types (for example, C6H6 or C8H18) consist of original or decayed fuel molecules, and their content increases not only when the mixture is enriched, but also when the mixture is lean (a > 1.15), which is explained by the increased amount of unreacted (unburned ) fuel due to excess air and misfires in individual cylinders. The formation of hydrocarbons also occurs due to the fact that the gas temperature at the walls of the combustion chamber is not high enough for fuel combustion, so here the flame is extinguished and complete combustion does not occur. Polycyclic aromatic hydrocarbons are the most toxic.

In diesel engines, light gaseous hydrocarbons are formed during the thermal decomposition of fuel in the flameout zone, in the core and in the leading edge of the flame, on the wall on the walls of the combustion chamber and as a result of secondary injection (boosting).

Solid particles include insoluble (solid carbon, metal oxides, silicon dioxide, sulfates, nitrates, asphalts, lead compounds) and soluble in organic solvent (resins, phenols, aldehydes, varnish, carbon deposits, heavy fractions contained in fuel and oil) substances.

Solid particles in the exhaust gases of supercharged diesel engines consist of 68...75% of insoluble substances, 25...32% of soluble substances.

Soot

Soot (solid carbon) is the main component of insoluble particulate matter. It is formed during volumetric pyrolysis (thermal decomposition of hydrocarbons in the gas or vapor phase with a lack of oxygen). The mechanism of soot formation includes several stages:

• embryo formation
• growth of nuclei to primary particles (hexagonal graphite plates)
• increase in particle size (coagulation) to complex conglomerate formations, including 100... 150 carbon atoms
• burnout

Soot release from the flame occurs at α = 0.33...0.70. In regulated engines with external mixture formation and spark ignition (petrol, gas), the likelihood of such zones appearing is insignificant. In diesel engines, local zones over-enriched with fuel are formed more often and the listed soot formation processes are fully realized. Therefore, soot emissions from exhaust gases from diesel engines are higher than from spark-ignition engines. The formation of soot depends on the properties of the fuel: the higher the C/H ratio in the fuel, the higher the soot yield.

In addition to soot, particulate matter contains sulfur and lead compounds. Nitrogen oxides NOx represent a set of the following compounds: N2O, NO, N2O3, NO2, N2O4 and N2O5. NO predominates in the exhaust gases of automobile engines (99% in gasoline engines and more than 90% in diesel engines). In the combustion chamber NO can form:

• during high-temperature oxidation of air nitrogen (thermal NO)
• as a result of low-temperature oxidation of nitrogen-containing fuel compounds (fuel NO)
• due to the collision of hydrocarbon radicals with nitrogen molecules in the zone of combustion reactions in the presence of temperature pulsations (fast NO)

The combustion chambers are dominated by thermal NO, formed from molecular nitrogen during the combustion of a lean fuel-air mixture and a mixture close to stoichiometric, behind the flame front in the combustion products zone. Mainly during the combustion of lean and moderately rich mixtures (α > 0.8), reactions occur according to a chain mechanism:

O + N2 → NO + N
N + O2 → NO+O
N+OH → NO+H.

In rich mixtures (and< 0,8) осуществляются также реакции:

N2 + OH → NO + NH
NH + O → NO + OH.

In lean mixtures, the yield of NO is determined by the maximum temperature of the chain-thermal explosion (maximum temperature 2800...2900 ° K), i.e., the kinetics of formation. In rich mixtures, the NO yield ceases to depend on the maximum explosion temperature and is determined by the kinetics of decomposition and the NO content decreases. When burning lean mixtures, the formation of NO is significantly influenced by the unevenness of the temperature field in the zone of combustion products and the presence of water vapor, which is an inhibitor in the chain reaction of NOx oxidation.

The high intensity of the process of heating and then cooling the mixture of gases in an internal combustion engine cylinder leads to the formation of significantly nonequilibrium concentrations of reacting substances. Freezing (quenching) of the formed NO occurs at the level of maximum concentration, which is found in the exhaust gases due to a sharp slowdown in the rate of NO decomposition.

The main lead compounds in automobile exhaust gases are chlorides and bromides, as well as (in smaller quantities) oxides, sulfates, fluorides, phosphates and some of their intermediate compounds, which at temperatures below 370 ° C are in the form of aerosols or solid particles. About 50% of lead remains in the form of carbon deposits on engine parts and in the exhaust pipe; the remainder escapes into the atmosphere with exhaust gases.

Large amounts of lead compounds are released into the air when this metal is used as an anti-knock agent. Currently, lead compounds are not used as antiknock agents.

Sulfur oxides

Sulfur oxides are formed during the combustion of sulfur contained in fuel by a mechanism similar to the formation of CO.

The concentration of toxic components in exhaust gases is assessed in volume percent, parts per million by volume - ppm (ppm, 10,000 ppm = 1% by volume) and less often in milligrams per 1 liter of exhaust gases.

In addition to exhaust gases, sources of environmental pollution for cars with carburetor engines are crankcase gases (in the absence of closed crankcase ventilation, as well as fuel evaporation from the fuel system.

The pressure in the crankcase of a gasoline engine, with the exception of the intake stroke, is significantly less than in the cylinders, so part of the air-fuel mixture and exhaust gases breaks through the leaks of the cylinder-piston group from the combustion chamber into the crankcase. Here they mix with oil and fuel vapors washed off the cylinder walls of a cold engine. Crankcase gases dilute the oil, promote water condensation, aging and contamination of the oil, and increase its acidity.

In a diesel engine, during the compression stroke, clean air breaks into the crankcase, and during combustion and expansion, exhaust gases with concentrations of toxic substances proportional to their concentrations in the cylinder. The main toxic components in diesel crankcase gases are nitrogen oxides (45...80%) and aldehydes (up to 30%). The maximum toxicity of crankcase gases of diesel engines is 10 times lower than that of exhaust gases, so the share of crankcase gases in a diesel engine does not exceed 0.2...0.3% of the total emission of toxic substances. Taking this into account, forced crankcase ventilation is usually not used in automobile diesel engines.

The main sources of fuel evaporation are the fuel tank and the power system. Higher temperatures in the engine compartment, due to more loaded engine operating modes and the relative tightness of the vehicle's engine compartment, cause significant fuel evaporation from the fuel system when the hot engine is stopped. Given the large emission of hydrocarbon compounds as a result of fuel evaporation, all car manufacturers currently use special systems for their capture.

In addition to hydrocarbons coming from the vehicle power system, significant atmospheric pollution with volatile hydrocarbons of automobile fuel occurs when refueling cars (on average 1.4 g CH per 1 liter of fuel filled). Evaporation also causes physical changes in the gasolines themselves: due to changes in the fractional composition, their density increases, starting qualities deteriorate, and the octane number of gasolines of thermal cracking and direct distillation of oil decreases. In diesel cars, fuel evaporation is practically absent due to the low volatility of diesel fuel and the tightness of the diesel fuel system.

The level of air pollution is assessed by comparing the measured and maximum permissible concentrations (MPC). MAC values ​​are established for various toxic substances for continuous, average daily and one-time exposure. The table shows the average daily MPC values ​​for some toxic substances.

Table. Permissible concentrations of toxic substances

According to research, a passenger car with an average annual mileage of 15 thousand km “inhales” 4.35 tons of oxygen and “exhales” 3.25 tons of carbon dioxide, 0.8 tons of carbon monoxide, 0.2 tons of hydrocarbons, 0.04 tons of oxides nitrogen. Unlike industrial enterprises, the emissions of which are concentrated in a certain area, a car disperses the products of incomplete combustion of fuel throughout almost the entire territory of cities, directly in the ground layer of the atmosphere.

The share of pollution from cars in large cities reaches large values.

Table. Share of road transport in total air pollution in the world's largest cities, %

Toxic components of exhaust gases and evaporations from the fuel system have a negative effect on the human body. The degree of exposure depends on their concentrations in the atmosphere, the condition of the person and his individual characteristics.

Carbon monoxide

Carbon monoxide (CO) is a colorless, odorless gas. The density of CO is less than air, and therefore it can easily spread in the atmosphere. Entering the human body with inhaled air, CO reduces the function of oxygen supply, displacing oxygen from the blood. This is explained by the fact that the absorption of CO by the blood is 240 times higher than the absorption of oxygen. CO has a direct effect on tissue biochemical processes, leading to disruption of fat and carbohydrate metabolism, vitamin balance, etc. As a result of oxygen starvation, the toxic effect of CO is associated with a direct effect on the cells of the central nervous system. An increase in the concentration of carbon monoxide is also dangerous because, as a result of oxygen starvation of the body, attention is weakened, the reaction slows down, and the performance of drivers decreases, which affects road safety.

The nature of the toxic effects of CO can be traced from the diagram shown in the figure.

Rice. Diagram of the effects of CO on the human body:
1 – death; 2 – mortal danger; 3 – headache, nausea; 4 – onset of toxic action; 5 – beginning of noticeable action; 6 – inconspicuous action; T,h - exposure time

It follows from the diagram that even with a low concentration of CO in the air (up to 0.01%), prolonged exposure to it causes headaches and leads to decreased performance. A higher concentration of CO (0.02...0.033%) leads to the development of atherosclerosis, myocardial infarction and the development of chronic pulmonary diseases. Moreover, the effects of CO on people suffering from coronary insufficiency are especially harmful. At a CO concentration of about 1%, loss of consciousness occurs after just a few breaths. CO also has a negative effect on the human nervous system, causing fainting, as well as changes in color and light sensitivity of the eyes. Symptoms of CO poisoning include headache, palpitations, difficulty breathing and nausea. It should be noted that at relatively low concentrations in the atmosphere (up to 0.002%), CO associated with hemoglobin is gradually released and human blood is cleared of it by 50% every 3-4 hours.

Hydrocarbon compounds

Hydrocarbon compounds have not yet been sufficiently studied regarding their biological effects. However, experimental studies showed that polycyclic aromatic compounds caused cancer in animals. In the presence of certain atmospheric conditions (calm air, intense solar radiation, significant temperature inversion), hydrocarbons serve as starting products for the formation of extremely toxic products - photooxidants, which have a strong irritating and generally toxic effect on human organs, and form photochemical smog. Particularly dangerous from the group of hydrocarbons are carcinogenic substances. The most studied is the polynuclear aromatic hydrocarbon benzo(a)pyrene, also known as 3,4 benzo(a)pyrene, a substance that appears as yellow crystals. It has been established that malignant tumors appear in places of direct contact of carcinogenic substances with tissue. If carcinogenic substances deposited on dust particles enter the lungs through the respiratory tract, they are retained in the body. Toxic hydrocarbons are also gasoline vapors entering the atmosphere from the fuel system, and crankcase gases escaping through ventilation devices and leaks in the connections of individual engine components and systems.

Nitric oxide

Nitric oxide is a colorless gas, and nitrogen dioxide is a red-brown gas with a characteristic odor. When nitrogen oxides enter the human body, they combine with water. At the same time, they form compounds of nitric and nitrous acids in the respiratory tract, irritating the mucous membranes of the eyes, nose and mouth. Nitrogen oxides are involved in processes leading to the formation of smog. The danger of their influence lies in the fact that poisoning of the body does not appear immediately, but gradually, and there are no neutralizing agents.

Soot

When soot enters the human body, it causes negative consequences in the respiratory organs. If relatively large soot particles with a size of 2...10 microns are easily removed from the body, then small ones with a size of 0.5...2 microns are retained in the lungs and respiratory tract, causing allergies. Like any aerosol, soot pollutes the air, impairs visibility on the roads, but, most importantly, heavy aromatic hydrocarbons, including benzo(a)pyrene, are adsorbed on it.

Sulfur dioxide SO2

Sulfur dioxide SO2 is a colorless gas with a pungent odor. The irritating effect on the upper respiratory tract is explained by the absorption of SO2 by the moist surface of the mucous membranes and the formation of acids in them. It disrupts protein metabolism and enzymatic processes, causing eye irritation and coughing.

Carbon dioxide CO2

Carbon dioxide CO2 (carbon dioxide) does not have a toxic effect on the human body. It is well absorbed by plants releasing oxygen. But when there is a significant amount of carbon dioxide in the earth’s atmosphere, absorbing the sun’s rays, a greenhouse effect is created, leading to the so-called “thermal pollution”. As a result of this phenomenon, the air temperature in the lower layers of the atmosphere increases, warming occurs, and various climatic anomalies are observed. In addition, an increase in CO2 content in the atmosphere contributes to the formation of “ozone” holes. With a decrease in ozone concentration in the earth's atmosphere, the negative impact of hard ultraviolet radiation on the human body increases.

The car is also a source of air pollution due to dust. While driving, especially when braking, rubber dust is formed as a result of friction of tires on the road surface, which is constantly present in the air on highways with heavy traffic. But tires are not the only source of dust. Solid particles in the form of dust are emitted with exhaust gases, brought into the city in the form of dirt on car bodies, formed from abrasion of the road surface, lifted into the air by vortex flows that arise when the car is moving, etc. Dust has a negative impact on human health and has a detrimental effect on the plant world.

In urban environments, the car is a source of warming the surrounding air. If 100 thousand cars are moving in a city at the same time, then this is equal to the effect produced by 1 million liters of hot water. Exhaust gases from cars, containing warm water vapor, contribute to climate change in the city. Higher steam temperatures increase heat transfer by the moving medium (thermal convection), resulting in increased precipitation over the city. The influence of the city on the amount of precipitation is especially clearly visible from its natural increase, which occurs in parallel with the growth of the city. Over a ten-year observation period in Moscow, for example, 668 mm of precipitation fell per year, in its environs - 572 mm, in Chicago - 841 and 500 mm, respectively.

Side effects of human activity include acid rain - combustion products dissolved in atmospheric moisture - nitrogen and sulfur oxides. This mainly applies to industrial enterprises whose emissions are discharged high above the surface level and which contain a lot of sulfur oxides. The harmful effects of acid rain include the destruction of vegetation and accelerated corrosion of metal structures. An important factor here is that acid rain, together with the movement of atmospheric air masses, can travel distances of hundreds and thousands of kilometers, crossing state borders. Periodicals contain reports of acid rain falling in different European countries, the USA, Canada, and even seen in protected areas such as the Amazon.

Temperature inversions, a special state of the atmosphere in which the air temperature increases with altitude rather than decreases, have an adverse effect on the environment. Surface temperature inversions are the result of intense radiation of heat from the soil surface, as a result of which both the surface and adjacent layers of air cool. This state of the atmosphere prevents the development of vertical air movements, so water vapor, dust, and gaseous substances accumulate in the lower layers, contributing to the formation of layers of haze and fog, including smog.

The widespread use of salt to combat ice on roads leads to a reduction in the service life of cars and causes unexpected changes in roadside flora. Thus, in England, the appearance of plants characteristic of sea coasts along the roads was noted.

A car is a strong polluter of water bodies and underground water sources. It has been determined that 1 liter of oil can make several thousand liters of water undrinkable.

A large contribution to environmental pollution is made by the processes of maintenance and repair of rolling stock, which require energy costs and are associated with high water consumption, the release of pollutants into the atmosphere, and the generation of waste, including toxic ones.

When performing vehicle maintenance, units, zones of periodic and operational forms of maintenance are involved. Repair work is carried out at production sites. Technological equipment, machine tools, mechanization equipment and boiler plants used in maintenance and repair processes are stationary sources of pollutants.

Table. Sources of release and composition of harmful substances in production processes at operational and repair enterprises of transport

Name of zone, section, department	Manufacturing process	Equipment used	Released harmful substances
Rolling stock washing area	Washing external surfaces	Mechanical washing (washing machines), hose washing	Dust, alkalis, synthetic surfactants, petroleum products, soluble acids, phenols
Maintenance areas, diagnostic area	Maintenance	Lifting and transporting devices, inspection ditches, stands, equipment for changing lubricants, components, exhaust ventilation system	Carbon monoxide, hydrocarbons, nitrogen oxides, oil mist, soot, dust
Mechanical mechanics department	Metalworking, boring, drilling, planing work	Lathe, vertical drilling, planing, milling, grinding and other machines	Abrasive dust, metal shavings, oil mist, emulsions
Elsktrotechnical department	Grinding, insulating, winding works	Grinding machine, electrotin baths, soldering equipment, test benches	Abrasive and asbestos dust, rosin, acid fumes, tertiary
Battery section	Assembly, disassembly and charging work	Washing and cleaning baths, welding equipment, shelving, exhaust ventilation system	Flushing solutions, acid vapors, electrolyte, sludge, washing aerosols
Fuel equipment department	Adjustment and repair work on fuel equipment	Test stands, special equipment, ventilation system	Gasoline, kerosene, diesel fuel. acetone, benzene, rags
Forging and spring department	Forging, hardening, tempering of metal products	Forge, thermal baths, exhaust ventilation system	Coal dust, soot, oxides of carbon, nitrogen, sulfur, contaminated wastewater
Mednitsko-Zhestyanitsky branch	Cutting, soldering, straightening, molding according to templates	Metal shears, soldering equipment, templates, ventilation system	Acid fumes, tertiary, emery and metal dust and waste
Welding department	Electric arc and gas welding	Equipment for arc welding, acetylene - oxygen generator, exhaust ventilation system	Mineral dust, welding aerosol, manganese, nitrogen, chromium oxides, hydrogen chloride, fluorides
Valve department	Glass cutting, repair of doors, floors, seats, interior decoration	Electric and hand tools, welding equipment	Dust, welding aerosol, wood and metal shavings, metal and plastic waste
Wallpaper department	Repair and replacement of worn, damaged seats, shelves, armchairs, sofas	Sewing machines, cutting tables, knives for cutting and cutting foam rubber	Mineral and organic dust, waste fabrics and synthetic materials
Tire fitting and repair area	Disassembly and assembly of tires, repair of tires and tubes, balancing work	Stands for disassembling and assembling tires, equipment for vulcanization, machines for dynamic and static balancing	Mineral and rubber dust, sulfur dioxide, gasoline vapors
Plot paint and varnish coatings	Removing old paint, degreasing, applying paint and varnish coatings	Equipment for pneumatic or airless spraying, baths, drying chambers, ventilation system	Mineral and organic dust, solvent vapors and paint sols, contaminated wastewater
Engine running-in area (for repair companies)	Cold and hot engine running-in	Run-in stand, exhaust ventilation system	Oxides of carbon, nitrogen, hydrocarbons, soot, sulfur dioxide
Parking lots and storage areas for rolling stock	Moving rolling stock units, waiting	Equipped open or closed storage area	Same

Wastewater

When operating vehicles, wastewater is generated. The composition and quantity of these waters are different. Wastewater is returned back to the environment, mainly to objects of the hydrosphere (river, canal, lake, reservoir) and land (fields, reservoirs, underground horizons, etc.). Depending on the type of production, wastewater at transport enterprises can be:

• car wash wastewater
• oily wastewater from production areas (cleaning solutions)
• wastewater containing heavy metals, acids, alkalis
• waste water containing paint, solvents

Wastewater from car washes accounts for 80 to 85% of the volume of industrial wastewater from motor transport organizations. The main pollutants are suspended substances and petroleum products. Their content depends on the type of vehicle, the nature of the road surface, weather conditions, the nature of the cargo being transported, etc.

Wastewater from the washing of units, components and parts (used washing solutions) is distinguished by the presence in it of a significant amount of petroleum products, suspended solids, alkaline components and surfactants.

Wastewater containing heavy metals (chromium, copper, nickel, zinc), acids and alkalis is most typical for car repair industries using galvanic processes. They are formed during the preparation of electrolytes, surface preparation (electrochemical degreasing, etching), electroplating and washing of parts.

During the painting process (using pneumatic spraying), 40% of the paint and varnish materials enter the air of the working area. When these operations are carried out in painting booths equipped with hydrofilters, 90% of this amount settles on the elements of the hydrofilters themselves, 10% is carried away with water. Thus, up to 4% of spent paint and varnish materials end up in wastewater from painting areas.

The main direction in the field of reducing pollution of water bodies, ground and underground waters by industrial wastewater is the creation of recycling water supply systems for production.

Repair work is also accompanied by soil contamination and the accumulation of metal, plastic and rubber waste near production areas and departments.

During the construction and repair of communication routes, as well as industrial and household facilities of transport enterprises, water, soil, fertile soils, subsoil mineral resources are removed from ecosystems, natural landscapes are destroyed, and interference in the animal and plant world occurs.

Noise

Along with other modes of transport, industrial equipment, and household appliances, the car is a source of artificial background noise in the city, which, as a rule, has a negative impact on humans. It should be noted that even without noise, if it does not exceed acceptable limits, a person feels discomfort. It is no coincidence that Arctic researchers have repeatedly written about “white silence”, which has a depressing effect on humans, while the “noise design” of nature has a positive effect on the psyche. However, artificial noise, especially loud noise, has a negative effect on the nervous system. The population of modern cities faces a serious problem of dealing with noise, since loud noise not only leads to hearing loss, but also causes mental disorders. The danger of noise exposure is aggravated by the human body’s ability to accumulate acoustic stimuli. Under the influence of noise of a certain intensity, changes occur in blood circulation, the functioning of the heart and endocrine glands, and muscle endurance decreases. Statistics show that the percentage of neuropsychiatric diseases is higher among people working in conditions of high noise levels. The reaction to noise is often expressed in increased excitability and irritability, covering the entire sphere of sensitive perceptions. People exposed to constant noise often find it difficult to communicate.

Noise has a harmful effect on the visual and vestibular analyzers, reduces the stability of clear vision and reflex activity. The sensitivity of twilight vision weakens, and the sensitivity of daytime vision to orange-red rays decreases. In this sense, noise is an indirect killer of many people on the world's highways. This applies both to vehicle drivers working in conditions of intense noise and vibration, and to residents of large cities with high noise levels.

Noise combined with vibration is especially harmful. If short-term vibration tones the body, then constant vibration causes the so-called vibration disease, i.e. a whole range of disorders in the body. The driver's visual acuity decreases, the field of vision narrows, color perception or the ability to estimate the distance to an oncoming car may change. These violations, of course, are individual, but for a professional driver they are always undesirable.

Infrasound is also dangerous, i.e. sound with a frequency less than 17 Hz. This individual and silent enemy causes reactions that are contraindicated for a person behind the wheel. The effect of infrasound on the body causes drowsiness, deterioration of visual acuity and a slow reaction to danger.

Of the sources of noise and vibration in a car (gearbox, rear axle, driveshaft, body, cabin, suspension, as well as wheels and tires), the main one is the engine with its intake and exhaust, cooling and power systems.

Rice. Analysis of truck noise sources:
1 – total noise; 2 – engine; 3 – exhaust system; 4 – fan; 5 – air intake; 6 – rest

However, when the vehicle speed is more than 50 km/h, the predominant noise is generated by the vehicle tires, which increases in proportion to the vehicle speed.

Rice. Dependence of vehicle noise on driving speed:
1 – range of noise dissipation due to different combinations of road surfaces and tires

The combined effect of all sources of acoustic radiation leads to the high noise levels that characterize a modern car. These levels also depend on other reasons:

• road surface condition
• speed and direction changes
• changes in engine speed
• loads
• etc.