Abstract on the topic:

"Ecological problems of modern cities"

INTRODUCTION

“Cities are a great creation of the mind and hands of man. They play a decisive role in the territorial organization of society. They serve as a mirror of their countries and regions. Leading cities are called spiritual workshops of humanity and engines of progress” - this is the admiring description of the city given by Georgy Mikhailovich Lappo in his book “Geography of Cities”.

One cannot but agree with him. Indeed, urbanization and population play an important role in the life of every country.

One of the most characteristic features of the development of modern society is the rapid growth of cities, the continuous rate of increase in the number of their inhabitants, the increasing role of cities in the life of society, the transformation of rural areas into urban areas, as well as the migration of the rural population to cities.

The relevance of this topic is as follows:

most of the world's citizens are born city dwellers;

at the beginning of the third millennium, five and a half billion of the seven billion people live in cities;

urbanization affects the ecological state of the environment.

1. URBAN ENVIRONMENT

The urban environment is a complex, key concept. The study of the properties and features of the urban environment opens the way to understanding the city, its essence as a phenomenon. The urban environment is the most important component of a city's potential. It allows the creative potential of society to be realized and contributes to the accumulation of energy of society to move forward.

The urban environment is a collection of numerous and varied channels of mass communications, forms and methods of communication, and connection to sources of various information. Its fundamental feature is increasing diversity. HE. Yanitsky concludes that scientific and technological progress cannot develop without an increasing diversity of connections and communication. Diversity creates a wide range of opportunities for introducing a person to the endless world of culture. The urban environment determines the attractiveness of a big city.

The urban environment is characterized by multicomponentity. It is formed by both material (elements of the city and nature) and spiritual components. The population is the subject towards whom the environment is oriented. And at the same time it is an element of the environment. The composition of the population greatly influences the state and properties of the environment.

The spiritual component of the urban environment is enriched by great literature. Such wonderful cities as St. Petersburg, Moscow, Paris have a large “literary population” - heroes of works who forever live in one city or another. The Petersburg of Pushkin, Gogol, Dostoevsky, Blok is also the Petersburg of their heroes.

The structural complexity and complexity of the dynamics of a city are associated with its properties such as inconsistency, problematicity, and paradox. The city is a contradictory form of territorial organization of society. The contradictions are inherent in it from the very beginning, contained in its very essence. They can be weakened by thoughtful regulation, or they can be strengthened by mistakes and miscalculations of managers and designers. But the root of problems and contradictions is only partly in the actions of people. The city itself creates contradictions and problems.

The city's resources are used by different functions, between which contradictions arise - a kind of competition of functions. There is a confrontation between old and new industries. Different segments of the population have different requirements for the organization of the urban environment and strive to shape it in accordance with their needs, tastes and ideas. The city, increasing in size, seems to grow out of its tight clothes. The streets are becoming too narrow to accommodate increased traffic flows. The center cannot cope with servicing both the city and the agglomeration. The capacity of utility systems is exhausted.

A metropolis is a system, but the system is very paradoxical. Miscellaneous elements megacities are developing at different rates. There is a mismatch of the system, a violation of the proportionality and compliance of the parts and elements that make up the metropolis. Although, when a metropolis is designed, this proportionality and mutual correspondence is strictly ensured on the basis of careful calculations.

Urbanization, on the one hand, improves the living conditions of the population, on the other, it leads to the displacement of natural systems by artificial ones, environmental pollution, and an increase in chemical, physical and psychological stress on the human body.

A metropolis changes almost all components of the natural environment - the atmosphere, vegetation, soil, relief, hydrographic network, groundwater, soil and even climate. The process of urbanization, driven generally by development social production and the nature of social relations, itself has an increasingly diverse influence on the development and location of production in other spheres of society, changing its social and economic structure, demographic indicators, and conditions for personal development.

Man constantly dreams of a better future. Since ancient times, he has either spontaneously or deliberately transformed and improved the appearance of populated areas. The vitality of cities is not at all surprising, because they accumulate material assets that often simply cannot be assessed - houses, public buildings, theaters, stadiums, roads, bridges, pipelines and parks.

The metropolis ultimately reflects the class character of society, its contradictions, vices and contrasts.

Megacities are centers of political and cultural life. They arose during slavery and developed under feudalism and capitalism. The process of population concentration in megacities is progressing significantly faster than growth total population. According to the UN, the world's urban population is growing by 4% per year.

The emergence of megalopolises means the spontaneous reconstruction of large areas of the Earth. At the same time, air and water basins, green areas suffer, transport connections are disrupted, which leads to discomfort in all respects. Many cities are expanding so that they can no longer fit on land and are beginning to “slide into the sea.”

The process of population concentration in cities is inevitable and essentially positive. But the structure of a perfect city, its industrial, “city-forming” factor came into conflict with the historical purpose of the city and its role in raising people’s living standards.

Modern large cities, especially megalopolises, have expanded spontaneously, including residential facilities, numerous scientific and public institutions, industrial enterprises and transport facilities, growing, expanding, merging with each other, crowding and destroying the living nature of the Earth. Modern industrial cities, especially some super-cities in capitalist countries, are in most cases a mass of concrete, asphalt, smoke, and toxic emissions. Below we discuss a number of problems of the metropolis, as well as the safety of life in the metropolis.

Humanity in the process of life certainly influences various ecological systems. Examples of such, most often dangerous, impacts are the draining of swamps, deforestation, destruction of the ozone layer, reversal of river flows, and dumping of waste into the environment. By doing this, a person destroys the existing connections in a stable system, which can lead to its destabilization, that is, to an environmental disaster.

Below we will consider one of the problems of human influence on the environment - the problem of urban waste.

Each large region, which is a territory with certain natural conditions and a specific type of economic development, deserves special consideration from an environmental point of view. The importance of regional environmental analysis lies in the fact that its results are of great practical importance (the problems of the region are “closer” to a person than the problems of a country, continent or planet). In addition, the ecological state of the regions ultimately determines the global state of natural components.

2. GENERAL ENVIRONMENTAL PROBLEMS OF CITIES OF THE WORLD

Environmental problems of cities, mainly the largest of them, are associated with excessive concentration of population, transport and industrial enterprises in relatively small areas, with the formation of anthropogenic landscapes that are very far from a state of ecological balance.

The growth rate of the world's population is 1.5-2.0 times lower than the growth of the urban population, which today includes 40% of the world's people. For the period 1939 - 1979. the population of large cities increased by 4 times, in medium-sized cities by 3 times and in small cities by 2 times.

The socio-economic situation has led to the uncontrollability of the urbanization process in many countries. The percentage of urban population in individual countries is: Argentina - 83, Uruguay - 82, Australia - 75, USA - 80, Japan - 76, Germany - 90, Sweden - 83. In addition to large millionaire cities, urban agglomerations or merged cities are growing rapidly. These are Washington - Boston and Los Angeles - San Francisco in the USA; the city of Ruhr in Germany; Moscow, Donbass and Kuzbass in the CIS.

The circulation of matter and energy in cities significantly exceeds that in rural areas. The average density of the Earth's natural energy flow is 180 W/m2, the share of anthropogenic energy in it is 0.1 W/m2. In cities it increases to 30-40 and even 150 W/m2 (Manhattan).

Over large cities, the atmosphere contains 10 times more aerosols and 25 times more gases. At the same time, 60-70% of gas pollution comes from road transport. More active moisture condensation leads to an increase in precipitation by 5-10%. Self-cleaning of the atmosphere is prevented by a 10-20% decrease in solar radiation and wind speed.

With low air mobility, thermal anomalies over the city cover atmospheric layers of 250-400 m, and temperature contrasts can reach 5-6 (C. Temperature inversions are associated with them, leading to increased pollution, fog and smog.

Cities consume 10 or more times more water per person than rural areas, and water pollution reaches catastrophic proportions. Wastewater volumes reach 1 m2 per day per person. Therefore, almost all large cities experience a shortage of water resources and many of them receive water from remote sources.

Aquifers under cities are severely depleted as a result of continuous pumping by wells and wells, and are also polluted to a considerable depth.

The soil cover of urban areas is also undergoing a radical transformation. In large areas, under highways and neighborhoods, it is physically destroyed, and in recreational areas - parks, squares, courtyards - it is severely destroyed, polluted by household waste, harmful substances from the atmosphere, enriched with heavy metals, bare soil contributes to water and wind erosion.

The vegetation cover of cities is usually almost entirely represented by “cultural plantings” - parks, squares, lawns, flower beds, alleys. The structure of anthropogenic phytocenoses does not correspond to zonal and regional types of natural vegetation. Therefore, the development of green spaces in cities takes place in artificial conditions and is constantly supported by humans. Perennial plants in cities develop under conditions of severe oppression.

3. IMPACT OF THE ENVIRONMENT ON THE HEALTH OF THE URBAN POPULATION

Atmospheric pollution greatly affects the health of the urban population. This is evidenced, in particular, by significant differences in the incidence of the population in certain areas of the same city.

Changes in the health of city residents are not only an indicator of the ecological state of the metropolis, but also its most important socio-economic consequence, which should determine the leading directions for improving the quality of the environment. In this regard, it is very important to emphasize that the health of city residents itself, within the biological norm, is a function of economic, social (including psychological) and environmental conditions.

In general, the health of city residents is influenced by many factors, especially the characteristic features of the urban lifestyle - physical inactivity, increased nervous stress, transport fatigue and a number of others, but most of all - environmental pollution. This is evidenced by significant differences in the morbidity of the population in different areas the same metropolis.

The most noticeable negative consequences of environmental pollution in a large city are manifested in the deterioration of the health of city residents compared to residents of rural areas. For example, conducted by M.S. Bedny and co-authors in-depth study of morbidity separate groups of the urban and rural population has convincingly shown that city dwellers more often suffer from neuroses, cerebrovascular diseases, diseases of the central nervous system, and respiratory organs than rural residents.

Along with air pollution, many other urban environmental factors negatively affect human health.

Noise pollution in cities is almost always local in nature and is mainly caused by means of transport - urban, railway and aviation. Already now, on the main highways of megacities, noise levels exceed 90 dB and tend to increase by 0.5 dB annually, which is the greatest danger to the environment in areas of busy transport routes. As medical studies show, increased noise levels contribute to the development of neuropsychiatric diseases and hypertension. The fight against noise in the central areas of cities is complicated by the density of existing buildings, which makes it impossible to build noise barriers, expand highways and plant trees that reduce noise levels on the roads. Thus, the most promising solutions to this problem are the reduction of the own noise of vehicles (especially trams) and the use of new noise-absorbing materials in buildings facing the busiest highways, vertical gardening of houses and triple glazing of windows (with the simultaneous use of forced ventilation).

A particular problem is the increase in vibration levels in urban areas, the main source of which is transport. This problem little studied, but there is no doubt that its importance will increase.

Vibration contributes to faster wear and destruction of buildings and structures, but the most significant thing is that it can negatively affect the most precise technological processes. It is especially important to emphasize that vibration brings the greatest harm to advanced industries and, accordingly, its growth can have a limiting effect on the possibilities of scientific and technological progress in megacities.

4. CONDITION OF THE AIR POSITION

Most megacities are characterized by extremely strong and intense air pollution. For most polluting agents, and there are hundreds of them in the city, we can say with confidence that they, as a rule, exceed the maximum permissible concentrations. Moreover, since a city is exposed to multiple pollutants simultaneously, their combined effects can be even more significant.

It is widely believed that as the size of a city increases, the concentration of various pollutants in its atmosphere also increases, but in reality, if we calculate the average concentration of pollution for the entire territory of the city, then in multifunctional cities with a population of more than 100 thousand people it is approximately at the same level and practically does not increase with increasing city size. This is explained by the fact that, simultaneously with the increase in emissions, which increase in proportion to population growth, the urban area is expanding, which evens out the average concentrations of pollution in the atmosphere.

A significant feature of large cities with a population of more than 500 thousand people is that with the increase in the territory of the city and the number of its inhabitants, the differentiation of pollution concentrations in different areas increases steadily. Along with low levels of pollution concentration in peripheral areas, it increases sharply in areas of large industrial enterprises and, especially in central areas. In the latter, despite the absence of large industrial enterprises, as a rule, increased concentrations of air pollutants are always observed. This is caused both by the fact that there is intense traffic in these areas, and by the fact that in the central areas the atmospheric air is usually several degrees higher than in the peripheral ones - this leads to the appearance of rising air currents over the city centers, sucking polluted air from industrial areas located on the near periphery.

Currently, great hopes in the field of air protection are associated with the maximum gasification of industry and the fuel and energy complex, but the effect of gasification should not be exaggerated. The point is that translation from solid fuel gas, of course, sharply reduces the volume of sulfur-containing emissions, but increases emissions of nitrogen oxides, the disposal of which is still technically problematic.

A similar situation arises when reducing carbon monoxide emissions, which is a product of incomplete combustion of fuel. By improving combustion modes, it is possible to reduce carbon monoxide emissions to a minimum, but at the same time as the temperature rises, the oxidation of atmospheric nitrogen also increases, leading to an increase in the volume of nitrogen oxides discharged into the atmosphere. Unlike stationary sources, air pollution from motor vehicles occurs at low altitudes and is almost always local in nature. Thus, the concentrations of pollution produced by road transport quickly decrease with distance from the transport highway, and in the presence of sufficiently high barriers (for example, in closed courtyards of houses) they can decrease by more than 10 times.

In general, vehicle emissions are significantly more toxic than emissions from stationary sources. Along with carbon monoxide, nitrogen oxides and soot (for diesel cars), a running car releases into the environment more than 200 substances and compounds that have a toxic effect.

There is no doubt that in the near future, air pollution in megacities by road transport will pose the greatest danger. This is mainly due to the fact that at present there are no fundamental solutions to this problem, although there is no shortage of individual technical projects and recommendations.

Let us briefly describe the main directions for solving the problem of reducing environmental pollution by motor vehicles.

4.1 Improvement of the internal combustion engine

This technically quite realistic direction can reduce specific fuel consumption by 10-15%, as well as reduce emissions by 15-20%. There is no doubt that this path can become very effective in the very near future, since it does not require major changes either in the automotive industry or in the vehicle maintenance and operation system. Here we should only take into account that the real environmental effect of these measures is not as high as it seems at first glance, since, for example, the reduction in carbon monoxide emissions is largely compensated by an increase in nitrogen oxide emissions.

Conversion of an internal combustion engine to gaseous fuel. Internal combustion engine. The existing long-term experience of operating a car using propane-butane mixtures shows a high environmental effect. The amount of carbon monoxide, heavy metals and hydrocarbons in automobile emissions is sharply reduced, but the level of nitrogen oxide emissions remains quite high. In addition, the use of gas mixtures is currently only possible on trucks and requires the establishment of a system of gas filling stations, so the capabilities of this solution are currently still limited.

Converting an internal combustion engine to hydrogen fuel is often touted as almost perfect solution problems, however, it is often forgotten that nitrogen oxides are also formed when hydrogen is used and that the extraction, combustion and transportation of large volumes of hydrogen are associated with great technical difficulties, are unsafe and very costly in economic terms. In a city with several hundred thousand cars, it would be necessary to have enormous reserves of hydrogen, the mere storage of which would require (to ensure the safety of the population) the alienation of vast territories. If we take into account that this would be supplemented by a developed network of gas stations, then such a city would be very unsafe for its residents. Even if we assume that an economically acceptable solution to the problem of storing hydrogen (including in the cars themselves) in a bound state will be found, then this problem, in our opinion, is unlikely to be promising in the coming decades.

4.2 Electric car

Replacing the car with an electric vehicle is also very heavily promoted in popular literature, but at present it is as unlikely to be feasible as the previous proposal. Firstly, even the most advanced batteries, along with their significant dead weight, which worsens the car’s parameters, require several times more energy to charge than a regular car would spend with equal work. Thus, the electric car, being the most energy-wasteful means of transport, while reducing environmental pollution at the place of its operation, sharply increases it at the place of energy production. Secondly, the production of batteries requires a significant amount of valuable non-ferrous metals, the shortage of which is growing almost faster than the shortage of oil and gas. And thirdly, an electric car, which is practically “clean” for a city street, is not so for the motorist himself, since when the batteries operate, many toxic substances are constantly released, which inevitably end up in the interior of the electric car. Even if we assume that all of the above problems would be technically resolved, it should be taken into account that it would take dozens of years and several tens, if not hundreds of billions of dollars to rebuild the entire automotive industry, change the vehicle fleet, and rebuild the vehicle maintenance and operation systems. Therefore, a battery-powered car is unlikely to become a promising solution to the problem of environmental pollution by motor vehicles.

In addition to those discussed above, there are dozens of others technical solutions, many of which are being developed into prototypes. Among them there are both unpromising ones, for example, a car with a flywheel battery, which can only move well on a perfectly flat and straight road - otherwise the gyroscopic effect of the flywheel will seriously interfere with control, and quite promising “hybrid” designs. Among the latter, the idea of ​​a freight trolleybus with a battery for interline movements is very interesting, the implementation of which, subject to the improvement of current collectors and the reconstruction of current drives, can dramatically reduce air pollution, especially in city centers.

In addition to improving the means of transport themselves, planning measures, measures to improve the management of traffic flows and measures to rationalize transportation within the metropolis can make a significant contribution to reducing gas pollution in the atmosphere of cities. The creation of a unified automated transportation management system in cities can dramatically reduce vehicle mileage within the city and, accordingly, reduce air pollution.

When characterizing air pollution in the city, it is necessary to mention that it is subject to noticeable fluctuations caused by both weather conditions and the operating mode of the enterprise and vehicles.

As a rule, the atmosphere is more polluted during the day than at night, and more in winter than in summer, but here, too, there are exceptions associated, for example, with photochemical smog in summer time or the formation of stagnant masses of polluted air over the metropolis at night. Megacities located in different climatic zones and in specific landscape conditions are characterized by various types of critical situations, during which atmospheric pollution can reach critical values, but in all cases they are associated with prolonged calm weather.

Atmospheric air pollution is the most serious environmental problem of a modern city; it causes significant damage to the health of citizens, material and technical facilities located in the city (buildings, facilities, structures, industrial and transport equipment, communications, industrial products, raw materials and semi-finished products) and green spaces .

It is easy to see that with the rise in price industrial equipment and industrial products, the damage caused by air pollution will steadily increase. Moreover, it turns out that already a number of the most advanced industries, such as electronics, precision engineering and instrument making, are experiencing serious difficulties in their development in urban areas. Enterprises in these industries have to spend a lot of money on cleaning the air entering their workshops, and despite this, in production facilities located in megacities, technology violations caused by air pollution are becoming more frequent every year. But even if in workshops for the production of high-precision and high-quality products it is possible to create conditions close to ideal, then, when leaving the workshop, it begins to be subject to the destructive effects of pollutants and can quickly lose its quality.

Thus, air pollution becomes a real brake on scientific and technological progress in cities, the effect of which will constantly intensify as the requirements for clean technology increase, the accuracy of industrial equipment increases, and microminiaturization spreads.

A similar increase in damage is observed with the accelerated destruction of building facades in the polluted atmosphere of cities.

5. INFLUENCE OF ATMOSPHERE POLLUTION ON HUMAN HEALTH

The subject of debate among professionals is the contribution of environmental pollution and its individual types to the increase in morbidity and mortality of the population, due to the complexity of the interaction of numerous influencing factors and the difficulties of identifying disease factors. The table provides a general list of human diseases that may be associated with environmental pollution.

List of diseases associated with air pollution

Pathology	Substances that cause pathology.
System diseases blood circulation	sulfur oxides, carbon monoxide, nitrogen oxides, sulfur compounds, hydrogen sulfide, ethylene, propylene, butylene, fatty acid, mercury, lead.
Diseases of the nervous system and sensory organs. Mental disorders	chromium, hydrogen sulfide, silicon dioxide, mercury.
Respiratory diseases	dust, sulfur and nitrogen oxides, carbon monoxide, sulfur dioxide, phenol, ammonia, hydrocarbons, silicon dioxide, chlorine, mercury.
Digestive diseases	carbon disulfide, hydrogen sulfide, dust, nitrogen oxides, chromium, phenol, silicon dioxide, fluorine.
Diseases of the blood and blood-forming organs	oxides of sulfur, carbon, nitrogen, hydrocarbons, nitrous acid, ethylene, propylene, hydrogen sulfide.
Diseases of the skin and subcutaneous tissue	fluorine-containing substances.
Diseases of the genitourinary organs	carbon disulfide, carbon dioxide, hydrocarbon, hydrogen sulfide, ethylene, sulfur monoxide, butylene, carbon monoxide.

Pollution can have different effects on the body and depends on its type, concentration, duration and frequency of exposure. The body's reaction is determined by individual characteristics, age, gender, and state of health of a person. Children, sick people, people working in hazardous working conditions, and smokers are more vulnerable. All registered and studied phenomena of increased mortality and morbidity in areas with high air pollution indicate the obviousness and widespread nature of such impacts from environmental pollution.

According to experts from the World Health Organization (WHO), there are five categories of public health reactions to environmental pollution:

increased mortality;

increased morbidity;

the presence of functional changes that exceed the norm;

the presence of functional changes that do not exceed the norm;

relatively safe condition.

These categories can be considered as relative indicators that collectively characterize the state of human health and the quality of the environment. An indicator of health, first of all, is the amount of health, i.e. average life expectancy.

If we keep this indicator in mind, the most important environmental risk factors include:

air pollution;

drinking water contamination.

In the human body, acute or chronic poisoning develops, and long-term pathogenic pathological processes also occur, depending on the dose, time and nature of exposure to chemical contaminants. Short-term intake of large quantities of toxic substances into the body leads to the development of a clinically pronounced pathological process - acute poisoning. Such poisonings are divided into mild, moderate and severe. The latter sometimes result in death.

Poisonings that are caused by systematic or periodic intake of relatively small amounts of toxic substances into the body are called chronic poisonings. These poisonings rarely have a pronounced clinical picture. Their diagnosis is very difficult, since the same substance causes liver damage in some people, hematopoietic organs in others, kidneys in others, and the nervous system in others. Only a small number of chemical pollutants, when exposed in small doses, cause a strictly specific pathological process, while the vast majority produce a so-called general toxic effect. By “long-term consequences” or “long-term effect” of the influence of chemical pollutants is meant the development of disease-causing processes and pathological conditions in people who have contact with chemical pollutants in the long term of their lives, as well as during the lives of several generations of their offspring. Long-term effects unite a wide group of pathological processes.

Pathological phenomena in the nervous system in a more distant period after chemical exposure cause diseases such as parkinsonism, polyneuritis, paresis and paralysis, psychosis; in the cardiovascular system - heart attacks, coronary insufficiency, etc.

Based on mortality statistics, one can judge the significance of long-term effects:

from cardiovascular pathologies (about 50%);

from malignant tumors (about 20%) in industrialized cities.

Naturally, the most sensitive organs to the effects atmospheric pollution are the organs of the respiratory system. Toxification of the body occurs through the alveoli of the lungs, the area of ​​which (capable of gas exchange) exceeds 100 m2. During gas exchange, toxicants enter the blood. Solid suspensions in the form of particles of various sizes settle in different parts of the respiratory tract.

6. WATER POLLUTION

Pollution of the water basin in cities should be considered in two aspects - water pollution in the water consumption area and pollution of the water basin within the city due to its wastewater.

Water pollution in the water consumption area is a serious factor that worsens the ecological condition of cities. It is produced both due to the discharge of part of the untreated wastewater from cities and enterprises located above the water intake zone of a given city and water pollution by river transport, and due to the entry into water bodies of part of the fertilizers and pesticides applied to the fields. Moreover, if the first types of pollution can be dealt with effectively by building treatment facilities, then it is very difficult to prevent pollution of the water basin caused by agricultural activities. In areas of high moisture, about 20% of fertilizers and pesticides applied to the soil end up in watercourses. This, in turn, can lead to eutrophication of water bodies, which further deteriorates water quality.

It is important to note that water treatment facilities of water pipelines are not able to purify drinking water from solutions of these substances, therefore drinking water may contain them in elevated concentrations and negatively affect human health. The fight against this type of pollution requires the use of fertilizers and pesticides in catchment areas exclusively in granular form, the development and implementation of rapidly decomposing pesticides, as well as biological methods of plant protection.

Cities are also powerful sources of water pollution.

In large cities, per capita (taking into account contaminated surface runoff), about 1 m3 of contaminated wastewater is discharged into water bodies every day. Therefore, cities need powerful wastewater treatment plants, the operation of which causes considerable difficulties. Thus, during the operation of a biological treatment plant for urban wastewater, about 1.5-2 tons of waste sludge are generated per year per inhabitant. Currently, such sludge is stored on land, occupying large areas, and causes soil water pollution. Moreover, the most toxic elements containing heavy metal compounds are first washed out of the sludge. The most promising solution to this problem is to put into practice technological systems, providing for the production of gas from sludge with subsequent combustion of the remaining sludge mass.

A particular problem is the penetration of polluted surface runoff into groundwater. Surface runoff from cities is always highly acidic. If there are chalk deposits and limestones under the city, the penetration of acidified waters into them inevitably leads to the emergence of anthropogenic karst. Voids formed as a result of anthropogenic karst directly under the city can pose a serious threat to buildings and structures, therefore, in cities where there is a real risk of its occurrence, a special geological service is needed to predict and prevent its consequences.

7. INFLUENCE OF POLLUTED WATER ON HUMAN HEALTH

Water is a mineral that ensures the existence of living organisms on Earth. Water is part of the cells of any animal and plant. An insufficient amount of water in the human body leads to a disruption in the removal of digestive metabolic products, the blood is depleted of water, and the person gets a fever. Good quality water is an important factor in the health and life of humans and animals.

Today, around the world, the greatest threat to land waters is pollution. Pollution refers to all sorts of physical and chemical deviations from the natural composition of water: frequent and prolonged turbidity, increased temperature, rotting organic substances, the presence of hydrogen sulfide and other toxic substances in water. To all this is added wastewater: domestic, Food Industry, Agriculture. Often wastewater contains petroleum products, cyanides, salts of heavy metals, chlorine, alkalis, and acids. We should not forget about water contamination with herbicides and radioactive substances. Also today, waters everywhere are polluted by garbage dumped from everywhere. In addition, waste water from fields ends up in water bodies untreated.

As a result of the growth of industry, water bodies and rivers are heavily polluted. Various categories of contaminants can be established depending on the chemical nature that causes them. At petrochemical and chemical industry enterprises, water is used as a solvent, and, as a rule, specific wastewater is formed. In pulp and paper and hydrolysis plants, water is needed as a working medium. In the same capacity, it is used in light and food industries. Among the pollutants from industrial enterprises, the most noticeable is hydrocarbon pollution. The production and widespread use of synthetic surfactants (surfactants), especially in the composition of detergents, causes their entry along with wastewater into many water bodies, including sources of domestic and drinking water supply. The ineffectiveness of water purification from surfactants is the reason for their appearance in drinking water in water supply systems. Surfactants can have a negative impact on water quality, the self-purifying ability of water bodies, and the human body.

Intensive use of land in agriculture has increased the pollution of water bodies by runoff from fields containing chemicals and pesticides. Many pollutants can enter the aquatic environment from the atmosphere through precipitation (for example, lead). The difference between lead concentrations that are harmless to humans and those that cause symptoms of poisoning is the smallest. The nervous and circulatory systems are the first to be affected; children are especially sensitive to lead poisoning.

Chemicals discharged along with wastewater, ending up in rivers and lakes, often change the aquatic environment. Under the influence of such substances, water may become unsuitable for human activity and supporting the life of flora and fauna.

Not only chemicals, but also organic ones can cause great damage. The discharge of organic substances in excessively large quantities leads to severe poisoning of natural waters. People themselves and their activities suffer from the pollution of natural waters. Water supply to populated areas depends entirely on rivers, and water treatment from high content organic and mineral impurities are becoming increasingly difficult and expensive. Public health is at serious risk. The consequences of certain substances in water, the complete removal of which cannot be ensured by any wastewater treatment system, can affect humans over time. Pollution fresh water is a serious problem for humanity.

8. MICROCLIMATIC CHARACTERISTICS OF MEGA CITIES

Economic activity, the layout of residential areas, and a limited number of green spaces lead to the fact that cities, especially large ones, develop their own microclimate, which generally worsens its environmental characteristics.

On windless days, a temperature inversion layer can form over large cities at an altitude of 100-150 m, which traps polluted air masses over the city territory. This, along with significant thermal emissions and intense heating of stone, brick and reinforced concrete structures, leads to heating of the central areas of the city.

Particular mention should be made of the unfavorable wind conditions that arise in many areas of new buildings with open construction. It is well known that changes in atmospheric pressure, especially its decrease, have a very adverse effect on the well-being of people suffering from cardiovascular diseases. At the same time, in many areas of new buildings, due to the irrational layout of neighborhoods, local drops in atmospheric pressure may be observed at certain points. Thus, in small gaps between two large houses and at certain wind directions, the speed of wind flows can increase significantly. According to the laws of aerodynamics, at these points there is a local drop in atmospheric pressure (up to tens of millibars), which from the inside of the block acquires a pulsating character (frequency about 5-6 Hz). A zone of such pulsating pressure extends 15-20m to the sides from the gap between the houses. A similar, although less clearly defined, situation is observed on the upper floors of buildings with flat roofs. Needless to say, staying in these areas for people suffering from cardiovascular diseases can negatively affect their health.

The solution to this problem constantly requires the implementation of a set of measures in the areas of new buildings to normalize the wind regime in individual microdistricts through a more rational layout of neighborhoods, the construction of wind protection structures and the planting of green spaces.

9. GREEN SPACE IN MEGA CITIES

The presence of green spaces in cities is one of the most favorable environmental factors. Green spaces actively cleanse the atmosphere, condition the air, reduce noise levels, and prevent the occurrence of unfavorable wind conditions; in addition, greenery in cities has a beneficial effect on a person’s emotional state. At the same time, green spaces should be as close as possible to a person’s place of residence, only then can they have the maximum positive environmental effect.

However, in cities, green spaces are distributed extremely unevenly.

Green construction in areas of new buildings also poses considerable difficulties of both a technical and economic nature. The cost of landscaping 1 hectare of territory costs an average of 40 thousand rubles, and the installation of a lawn on the same territory costs 12 thousand rubles. Landscaping small areas costs even more, reaching 20-30 thousand rubles. for 1 m2. It is clear that in the latter case it is cheaper and easier to asphalt the courtyard area than to landscape it. From a technical point of view, green construction is hampered by the clutter of the territory of new buildings and the burial of construction waste in the soil. However, the maximum possible greening of urban areas is one of the most important environmental measures in cities.

10. ECOLOGY OF PRODUCTION AND RESIDENTIAL ENVIRONMENT

Concluding the analysis of the main factors shaping the ecological state in cities, let us dwell on one more problem directly related to human ecology. The factors shaping the urban environment were mentioned above; meanwhile, an adult resident of a large city spends the vast majority of time in confined spaces on a weekday - 9 hours. At work, 10-12 - at home and at least an hour in transport, shops and other public places and, thus, is in direct contact with the city environment for approximately 2-3 hours a day. This fact forces us to pay especially serious attention to the environmental characteristics of industrial and residential environments.

Creating comfortable conditions in confined spaces and, above all, purified conditioned air and a reduced noise level can significantly reduce the negative impact of the urban environment on human health, and these measures require relatively small material costs. However, not enough attention has yet been paid to resolving this issue. In particular, even in latest projects residential buildings often do not provide design options for installing air conditioners and air filters. In addition, within the living environment itself there are many factors influencing its quality. These should include gas kitchens, significantly increasing the pollution of the living environment, low air humidity (in the presence of central heating), the presence of a significant amount of various allergens - in carpets, upholstered furniture and even in heat-insulating materials used in construction, and many other factors. The negative consequences of all of the above should not only be provided for during new construction and major renovation, but active actions are also required to improve the quality of the living environment from every citizen.

11. MUNICIPAL WASTE PROBLEM

Before the era of agglomeration, waste disposal was facilitated due to the absorption capacity of the environment: land and water. Peasants, sending their products from the field directly to the table, without any processing, transportation, packaging, advertising or distribution network, brought in little waste. Vegetable peelings and the like were fed or used in the form of manure as soil fertilizer for the following year's crop. The movement to cities led to a completely different consumer structure. Products began to be exchanged, and therefore packaged for greater convenience.

Currently, New Yorkers throw away a total of about 24,000 tons of materials per day. This mixture, consisting mainly of a variety of trash, contains metals, glass containers, waste paper, plastic and food scraps. This mixture contains large amounts of hazardous waste: mercury from batteries, phosphorus carbonates from fluorescent lamps and toxic chemicals from household solvents, paints and preservatives for wood coatings.

A city the size of San Francisco has more aluminum than a small bauxite mine, more copper than the average copper replica, and more paper than could be made from a huge amount of wood.

From the beginning of the 70s to the end of the 80s, household waste in Russia doubled. This is millions of tons. The situation today seems to be as follows. Since 1987, the amount of garbage in the country has doubled and amounted to 120 billion tons per year, including industry. Today, Moscow alone throws out 10 million tons of industrial waste, approximately 1 ton for each resident!

As can be seen from the above examples, the scale of environmental pollution from urban waste is such that the severity of the problem is growing.

12. POSSIBLE WAYS TO SOLUTION PROBLEMS

Around 500 BC, the first known edict was issued in Athens, prohibiting throwing garbage on the streets, providing for the organization of special landfills and ordering garbage collectors to dump waste no closer than a mile from the city.

Since then, the garbage has been stored in various storage facilities in rural areas. As a result of the growth of cities, the available space in their surroundings decreased, and the unpleasant odors and the increased number of rats caused by landfills became unbearable. Free-standing landfills have been replaced by waste storage pits.

About 90% of waste in the United States is still landfilled. But U.S. landfills are filling up quickly, and fears of groundwater contamination make them unwelcome neighbors. This practice has caused people in many populated areas countries to stop consuming well water. Wanting to reduce this risk, the city of Chicago declared a moratorium on the development of new landfill sites in August 1984 until a new type of monitoring was developed to monitor the movement of methane, since if its formation is not controlled, it can explode.

Even simple waste disposal is an expensive undertaking. From 1980 to 1987 the cost of waste disposal in the USA increased from 20 to 90 dollars per 1 ton. The upward trend in cost continues today.

In densely populated areas of Europe, the waste disposal method, as requiring too large areas and contributing to groundwater pollution, was preferred to another method - incineration.

The first systematic use of waste ovens was tried in Nottingham, England, in 1874. Incineration reduced the volume of waste by 70-90%, depending on the composition, so it found its way onto both sides of the Atlantic. The populous and most important cities soon introduced experimental stoves. The heat released by burning waste began to be used to generate electrical energy, but not everywhere these projects were able to justify the costs. Large costs for them would be appropriate when there would be no cheap method of disposal. Many cities that used these stoves soon abandoned them due to deteriorating air composition. Waste disposal remains one of the most popular methods of solving this problem.

The most promising way to solve the problem is to recycle urban waste. The following main directions in processing have been developed: organic matter is used to produce fertilizers, textile and paper waste is used to produce new paper, scrap metal is sent for smelting. The main problem in recycling is sorting waste and developing technological processes for recycling.

The economic feasibility of a waste recycling method depends on the cost of alternative methods of waste disposal, the position on the market for recyclable materials and the costs of their processing. For many years, recycling activities were hampered by the belief that any business must be profitable. But what was forgotten was that recycling, compared to landfilling and incineration, is the most effective way to solve the waste problem, since it requires fewer government subsidies. In addition, it saves energy and protects the environment. And as the cost of landfill space rises due to stricter regulations, and furnaces are too expensive and dangerous to the environment, the role of recycling will steadily grow.

CONCLUSION

Nature, untouched by civilization, must remain a reserve, which over time, when most of the globe will serve industrial, aesthetic and scientific purposes, will begin to acquire all higher value standard, criterion, in particular aesthetic, in the future it is possible that other currently unknown meanings of these zones may appear. Therefore, a rational, scientifically based approach to the practice of expanding areas of virgin nature and nature reserves is necessary, especially since as the scientific and technological revolution develops, the volume of negative impacts on natural aesthetically valuable objects increases so much that cultural activities, aimed at compensating for the damage caused, sometimes fails to cope with its tasks.

In these conditions, determining the optimal relationship between primary nature and the cultural landscape is of particular importance. A justified strategy and systematic organization in the interactions of society with the natural environment is a new stage in environmental management. In the conditions of developed socialism, all forms of activity for the aesthetic reconstruction of the natural environment acquire special importance. This is, first of all, the culture of design of areas under production and restoration, the architecture of recreational landscapes, the increase in territories for national parks, nature reserves, the development of the art of creating gardens and parks, small dendro-decoration forms. Of particular importance is the improvement of tourism as a form of recreation for the broad masses of working people.

There is also a gap between increasing the general cultural level of the population and the culture of attitudes towards nature. Therefore, there is a need, firstly, to create a system of environmental measures, secondly, scientific justification and inclusion in this system of criteria for the aesthetic assessment of nature, thirdly, the development of a system of environmental education, improvement of all types of creativity related to nature.

BIBLIOGRAPHY

1. Bystrakov Yu.I., Kolosov A.V. Social ecology. - M., 1988.
2. Milanova E.V., Ryabchikov A.M. Usage natural resources Protection of Nature. M.: Higher. school, 1996.280 p.
3. Lvovich N.K. Life in a metropolis. M.: Nauka, 2006.254 p.
4. Dorst S. Before nature dies. M.: Progress, 1978.415 p.
5. Bezuglaya E.Yu., Rastorgueva G.P., Smirnova I.V. What does an industrial city breathe? L.: Gidrometeoizdat, 1991.255 p.

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Environmental problems of cities It is often believed that the environmental condition of cities has noticeably deteriorated in recent decades as a result of the rapid development of industrial production. But this is a fallacy. Environmental problems of cities arose along with their birth. The cities of the ancient world were characterized by a very crowded population. For example, in Alexandria the population density in the I-II centuries. reached 760 people, in Rome - 1,500 people per 1 hectare (for comparison, let’s say that in the center of modern New York no more than 1 thousand people live per 1 hectare). The width of streets in Rome did not exceed 1.5-4 m, in Babylon - 1.5-3 m. The sanitary improvement of cities was at an extremely low level. All this led to frequent outbreaks of epidemics, pandemics, in which diseases covered the entire country, or even several neighboring countries. The first recorded plague pandemic (known in literature as the “Plague of Justinian”) occurred in the 6th century. in the Eastern Roman Empire and covered many countries of the world. Over 50 years, the plague claimed about 100 million human lives. Now it is difficult to even imagine how ancient cities with their many thousands of people could manage without public transport, without street lighting, without sewerage and other elements of urban amenities. And, probably, it is no coincidence that it was at that time that many philosophers began to have doubts about the advisability of the existence of large cities. Aristotle, Plato, Hippodamus of Miletus, and later Vitruvius repeatedly came out with treatises that addressed issues optimal sizes settlements and their structure, problems of planning, construction art, architecture and even the relationship with the natural environment. Medieval cities were already significantly smaller in size than their classical counterparts and rarely numbered more than several tens of thousands of inhabitants. So, in the 14th century. the population of the largest European cities - London and Paris - was 100 and 30 thousand inhabitants, respectively. However, urban environmental problems have not become less acute. Epidemics continued to be the main scourge. The second plague pandemic, the Black Death, broke out in the 14th century. and carried away almost a third of Europe's population. With the development of industry, rapidly growing capitalist cities quickly surpassed their predecessors in population. In 1850, London crossed the million mark, then Paris. By the beginning of the 20th century. there were already 12 “millionaire” cities in the world (including two in Russia). The growth of large cities proceeded at an ever faster pace. And again, as the most formidable manifestation of the disharmony between man and nature, outbreaks of epidemics of dysentery, cholera, and typhoid fever began one after another. The rivers in the cities were terribly polluted. The Thames in London began to be called the “black river”. Fetid streams and ponds in other large cities became sources of gastrointestinal epidemics. Thus, in 1837, in London, Glasgow and Edinburgh, a tenth of the population fell ill with typhoid fever and approximately a third of patients died. From 1817 to 1926, six cholera pandemics were recorded in Europe. In Russia, in 1848 alone, about 700 thousand people died from cholera. However, over time, thanks to the achievements of science and technology, advances in biology and medicine, and the development of water supply and sewerage systems, the epidemiological danger began to weaken significantly. We can say that at that stage the environmental crisis of large cities was overcome. Of course, such overcoming each time cost colossal efforts and sacrifices, but the collective intelligence, perseverance and ingenuity of people always turned out to be stronger than the crisis situations they themselves created. Scientific and technical achievements, based on outstanding natural scientific discoveries of the 20th century. contributed to the rapid development of productive forces. This is not only the enormous successes of nuclear physics, molecular biology, chemistry, and space exploration, but also the rapid, continuous growth in the number of large cities and urban population. The volume of industrial production has increased hundreds and thousands of times, the power supply of humanity has increased more than 1000 times, the speed of movement has increased by 400 times, the speed of information transfer has increased by millions of times, etc. Such active human activity, of course, does not pass without a trace on nature , since resources are drawn directly from the biosphere. And this is only one side of the environmental problems of a big city. Another is that in addition to the consumption of natural resources and energy drawn from vast spaces, modern city with a population of millions produces a huge amount of waste. Such a city annually emits into the atmosphere at least 10-11 million tons of water vapor, 1.5-2 million tons of dust, 1.5 million tons of carbon monoxide, 0.25 million tons of sulfur dioxide, 0.3 million tons of nitrogen oxides and a large the amount of other pollution that is not indifferent to human health and the environment. In terms of the scale of its impact on the atmosphere, a modern city can be compared to a volcano. What are the features of the current environmental problems of large cities? First of all, there are numerous sources of impact on the environment and their scale. Industry and transport - and these are hundreds of large enterprises, hundreds of thousands or even millions of vehicles - are the main culprits of pollution of the urban environment. The nature of waste has also changed in our time. Previously, almost all waste was of natural origin (bones, wool, natural fabrics, wood, paper, manure, etc.), and they were easily included in the cycle of nature. Nowadays, a significant part of the waste is synthetic substances. Their transformation under natural conditions occurs extremely slowly. One of the environmental problems is associated with the intensive growth of non-traditional “pollution”, which has a wave nature. Intensifying electromagnetic fields high voltage power lines, radio broadcasting and television stations, as well as large number electric motors. The overall level of acoustic noise increases (due to high transport speeds, due to work various mechanisms and cars). Ultraviolet radiation, on the contrary, decreases (due to air pollution). Energy costs per unit area increase, and, consequently, heat transfer and thermal pollution increase. Under the influence of the huge masses of multi-storey buildings, the properties of the geological rocks on which the city stands are changing. The consequences of such phenomena for people and the environment have not yet been sufficiently studied. But they are no less dangerous than pollution of water and air basins and soil and vegetation cover. For residents of large cities, all this together results in a great overstrain of the nervous system. City dwellers get tired quickly, are susceptible to various diseases and neuroses, and suffer from increased irritability. Chronically poor health of a significant part of urban residents in some Western countries is considered a specific disease. It was called "urbanite". Motor transport and environment In many large cities, such as Berlin, Mexico City, Tokyo, Moscow, St. Petersburg, Kiev, air pollution from automobile exhaust and dust accounts, according to various estimates, from 80 to 95% of all other pollution. Smoke emitted from factory chimneys, fumes from chemical industries and all other waste from the activities of a large city account for approximately 7% of total mass pollution. Car exhaust in cities is especially dangerous because it pollutes the air mainly at the level of human growth. And people are forced to breathe polluted air. A person consumes 12 m 3 of air per day, a car - a thousand times more. For example, in Moscow, road transport absorbs 50 times more oxygen than the entire population of the city. In calm weather and low atmospheric pressure on busy highways, the oxygen content in the air often decreases to a value close to critical, at which people begin to suffocate and faint. Not only the lack of oxygen affects, but also harmful substances from car exhaust. This is especially dangerous for children and people with poor health. Cardiovascular and pulmonary diseases are worsening, and viral epidemics are developing. People often do not even suspect that this is due to poisoning from automobile gases. The number of cars in cities and on highways is increasing from year to year. Ecologists believe that where their number exceeds one thousand per km 2, the habitat can be considered destroyed. The number of cars is taken in terms of passenger cars. Heavy transport vehicles running on oil fuel especially pollute the air, destroy road surfaces, destroy green spaces along roads, and poison reservoirs and surface waters. In addition, they emit such a huge amount of gas that in Europe and the European part of Russia it exceeds the mass of evaporated water from all reservoirs and rivers. As a result, cloudiness becomes more frequent and the number of sunny days decreases. Gray, sunless days, unheated soil, constantly high air humidity - all this contributes to growth various diseases, reducing agricultural yields. More than 3 billion tons of oil are produced annually in the world. They are mined with hard work, at enormous costs, and with great environmental damage to nature. A significant part of it (about 2 billion) is spent on gasoline and diesel vehicles. The average efficiency of a car engine is only 23% (for gasoline engines - 20, for diesel engines - 35%). This means that more than half of the oil is burned in vain, used to heat and pollute the atmosphere. But this is not all the losses. The main indicator is not engine efficiency, but vehicle load factor. Unfortunately, road transport is used extremely inefficiently. A smartly built vehicle must be able to carry more than its own weight, which is where its efficiency lies. In practice, only bicycles and light motorcycles meet this requirement; other vehicles basically carry themselves. It turns out that the efficiency of road transport is no more than 3-4%. A huge amount of petroleum fuel is burned, and energy is spent extremely irrationally. For example, one KamAZ vehicle consumes so much energy that it would be enough to heat 50 apartments in winter. For many centuries, the main form of transport for humans was the horse. Energy in 1 liter. With. (this is an average of 736 W), added to a person’s own power, allows him to move quickly enough and perform almost any necessary work. The boom in the automotive industry took us to power levels of 100, 200, 400 hp. pp., and now it is extremely difficult to return to the quite sufficient norm - 1 liter. pp., in which it would not be so difficult to ensure the ecological purity of the environment. How to solve the problem of creating efficient transport? Converting vehicles to gas fuel, switching to electric vehicles, installing a special absorber of harmful combustion products on each car and burning them in the muffler - all this is a search for a way out of the impasse in which not only Russia, but all of Europe, the USA, Canada, Mexico find themselves. Brazil, Argentina, Japan, China. Unfortunately, none of these paths leads to a complete solution to the problem. With any of them, there is excessive energy consumption, emissions of steam, carbon dioxide and much more. Obviously, a well-balanced set of measures is needed. And their mandatory implementation should be based on clear, strict laws, among which may be, for example, the following: a ban on the production of cars that consume more than 1-2 liters of fuel per ton of vehicle weight over a mileage of 100 km (single exceptions are possible); taking into account that a passenger car most often carries one or two people, it is advisable to produce more two-seater cars. The amount of tax on transport (car, tractor, trailer, etc.) should be determined by the amount of fuel consumed. This will make it possible to bring into line the economic feasibility of transporting goods by road and the increasing level of environmental pollution. Whoever pollutes our environment more is obliged to pay more tax to society. One of the ways to reduce harmful automobile emissions is the use of new types of automobile fuel: gas, methanol, methyl alcohol or a mixture of it with gasoline - gasohol. For example, all public transport in Stockholm has been running on methanol for several years. The impact of automobile exhaust gases on the atmosphere is significantly reduced by ordinary green spaces. An analysis of the air in adjacent sections of the same highway shows that there are fewer pollutants where there is an island of greenery, at least a few trees or shrubs. The volume of toxic substances in the air directly depends on the speed of traffic on city streets. The more traffic jams, the thicker the exhaust. In this regard, it is necessary to continuously improve the city's road transport system to create optimal conditions traffic movement.

Significance of the environmental problem

There are areas on Earth that, due to a number of natural and environmental features, were most favorable for development ancient civilizations - these are plains suitable for cultivation, rivers, lakes and other places. They are a kind of platforms of attraction for primitive people. Five such favorable places can be distinguished: the Nile and Mesopotamia with Egypt and Sumer, the valleys of the Ganges and Indus rivers with the civilizations of India, the Yellow River (Huang He) basin with the Chinese civilization and, finally, the later Central America with the Mayan civilization, the islands of the Pacific and Indian Oceans with the Polynesian civilization, while each ethnic group experienced periods of its most active activity. Under pressure from more powerful ethnic groups, small civilizations faded into the background or disappeared altogether. This is how the civilizations of Central Africa, Easter Island, etc. disappeared. A more sustainable path of development was preserved only by European civilization, with roots associated with Mesopotamia, Egypt, Rome, and Hellas. For a long time, Europeans perceived the religious and philosophical teachings of China and India as a path to cultivating passivity, detachment, and contemplation. However, at the end of the 20th century. Western civilization began to rethink the spiritual guidelines of its development. From the point of view of environmental ethics, Judeo-Christian dogmas that affirm the right of man to dominate nature are inferior to the ideas of Buddhism, Taoism and other Eastern teachings that preach the inextricable connection of man with nature. The history of urban life is no less significant than the development of agriculture and the production of certain goods. The way of life in the cities of antiquity was not much different from the modern one. However, humanity has preserved the memory of the seven wonders of the ancient world: the Egyptian pyramids at Giza, the Hanging Gardens of Babylon, the statue of Zeus at Olympia, the Colossus of Rhodes, the Temple of Artemis at Ephesus, the Mausoleum of Halicarnassus and the Lighthouse of Alexandria. River valleys represented blooming oases among the surrounding desert landscapes. Man, having developed river valleys, created man-made agricultural landscapes, the functioning of which was supported by constant creative activity. The close dependence of people's lives on the regime of rivers, such as the Nile, ensured the longer existence of the Egyptian state. The magnificent pyramids and temples are excellent symbols of this stability. Babylon, which was the capital of the Middle East for one and a half thousand years, existed from the 19th to the 6th centuries. BC e. The death of the Babylonian kingdom was a consequence of inept management. The Egyptians, who had extensive experience in constructing irrigation structures to irrigate land in the Nile Valley, proposed building a canal and increasing the area of ​​irrigated land between the Tigris and Euphrates rivers. Water irrigated the lands underlying saline soils. Secondary soil salinization has begun. Water in the Euphrates, where it was taken from new channel, began to flow more slowly, causing sedimentation in the old irrigation network. She started to fail. Thus, the consequences of another “victory over nature,” wrote L.N. Gumilev (1912-1992), “destroyed the great city.” By the beginning of the new era, only ruins remained from it. Techniques for cultivating and irrigating land, plant selection - all these achievements of the ancient civilizations of Mesopotamia and the Nile were used by subsequent peoples, which ensured their rapid development. And here's what's interesting. On the Cheops pyramid it was written as a warning to descendants: “People will die from the inability to use the forces of nature and from ignorance of the true world.” The ancient civilizations of the Mediterranean, as we know from history, were repeatedly subjected to major tectonic disasters, which led to the death of the existing civilization. In the first case, in the Atlantic Ocean there was a movement of the earth's crust along a rift fracture, which may have destroyed the legendary Atlantis. The second event was associated with the eruption of the Santorini volcano, as a result of which the Cretan civilization perished, and with the mass migration of the Phoenicians to the western part of the Mediterranean Sea and beyond. The emergence of the Ol-Mec civilization on the shores of the Gulf of Mexico dates back to this period. The Mayans called themselves descendants of sailors who came from the East. It is likely that grandiose tectonic disasters could lead not only to local, but also to global migrations of peoples. It should be noted that already in ancient times, great people had knowledge and understanding of those problems that we now call environmental (ancient Greek philosophers Plato (427-348 BC), Aristotle (384-322 BC). Signs ecological crisis were characteristic of civilization Ancient Greece. Forests were replaced by fields, gardens, and vineyards. Deforestation led to soil erosion, especially on slopes. The washing away of soils from mountain slopes radically changed the appearance of active landscapes. According to the testimony of the ancient Greek naturalist Theofrasta (372 - 287 BC), the ship forest grew only in mountainous Arcadia and outside Greece. In turn, the conquest of nature in Ancient Rome resulted in an exacerbation of environmental problems. Mostly forests, arable lands, and mountain slopes were affected. The harvests from the fields became less and less. In August 1998, a catastrophic flood occurred in China, which flooded the northern provinces of Inner Mongolia and the Chinese Amur region, the central parts of China in the provinces of Hubei and Jiangxi, killing more than 10 thousand residents. The flood affected almost 20% of China's population and affected the national economy. The tragedy raised questions: what to do and who is to blame? Scientists point not only to natural, but also to man-made causes of the disaster: deforestation along the Yangtze led to soil erosion, soil washout into the river and an increase in the height of the river bottom. The Renaissance with its medieval period is called in history the era of the “great uprooting”. By the beginning of the 11th century. influence spread to the peoples inhabiting Western Europe Roman Catholic Church: the feudal system was established. In the XI - XIII centuries. There was massive deforestation for agriculture. Castles, monasteries, cities were built, and the mining industry developed. At this stage, the environmental situation in Europe became very complicated. Defensive walls to some extent still limited the growth of cities. However, the lack of sewerage has led to the contamination of ground and surface waters. And due to the cramped conditions of the building, fires, which were not uncommon, had devastating consequences. Crowded population and unsanitary conditions contributed to the spread of epidemics. Thus, in the middle of the 14th century. According to various estimates, up to 50% of the entire population of Europe died from the plague epidemic. Arabic culture has been represented by many scholars. First of all, we should note the legendary physician Ibn Sina (Avicena) (c. 980-1037), who wrote in the chapter “On things that arise from causes belonging to general causes” about the influence of the surrounding air on the body, the seasons and natural phenomena. Ibn Sina also dealt with the problems of the origin of the animal world and the formation of the relief of the earth's surface. At the turn of the VIII - IX centuries. arose Kievan Rus. With the adoption of Christianity in 988, relations between the Russians and the Greeks, and then with others, intensified. European countries. Before the baptism of Rus', the enlighteners Cyril (c. 827 - 869) and Methodius (c. 815 - 855), brothers from Thessaloniki, created the Slavic alphabet and translated the sacred scriptures from Greek. In the 12th century. The most ancient chronicle, The Tale of Bygone Years, was compiled. This chronicle mentions not only historical events, but also remarkable natural phenomena. In the age of enlightenment, observation and experiment began to play an important role in the natural sciences. The body of knowledge from the field of natural sciences (in the explanation of nature) is called natural philosophy - philosophy of nature. Natural philosophers include: Rene Descartes (1596-1650), Voltaire (1694-1778), Jean-Jacques Rousseau (1712-1778), Buffon (1707-1788), Immanuel Kant (1724-1804). The century of enlightenment in Russia (XVIII) is inextricably linked with the name of M.V. Lomonosov (1711 -1765). In his writings and studies “On the Layers of the Earth,” where he formulated the problems of geology and other tasks, Lomonosov supported the position of transformism, spreading the idea of ​​​​the development of not only the earth’s crust, but the entire world. Thus, M.V. Lomonosov was the first Russian natural philosopher-transformist who paved the way for the evolutionary idea. The successes of enlightenment and the rise of creative thought were a prerequisite for the renewal of the ancient science of geography, and within its framework, in the era of natural science, for the emergence of a new science - ecology. The scientific foundations of natural science, as well as ecology, were formed in line with natural philosophy, but with some contradiction: on the one hand, the materiality and knowability of environmental laws was affirmed, on the other, the initial act of creation of the world by God was explicitly or covertly recognized. At the same time, it became obvious that philosophy without natural science is as impossible as natural science without philosophy (A.I. Herzen (1812-1870) “Letters on the Study of Nature”). In the era of natural science the world in all its diversity as living nature attracted the attention of many representatives of science, naturalists and biologists who made a huge invaluable contribution to the foundations of natural science and knowledge of the environment: Jean Baptiste Lamarck, Wolfgang Goethe, Alexander Humboldt and Charles Darwin. Among the Russian researchers, the geographer and geologist, honorary member St. Petersburg Academy sciences Pyotr Aleksandrovich Chikhachev (1808-1890), who outlined the problems of interaction between man and nature. Leading a geological expedition through the Eastern Altai and adjacent regions of Siberia, he saw how forest vegetation was dying. P.A. Chikhachev described what means hunters resorted to to detect and track the beast, while destroying wonderful forests. Using the example of the Zmeinogorsk deposits, Chikhachev showed the damage polymetallic and silver mines cause to nature. He wrote: “The processing site is filled with firewood, which is lit and heats the rock for a long time, after which it is doused cold water and cracks. This is considered a cheaper method than using gunpowder, although the forests have already retreated 125 km from Zmeinogorsk. Human habitation also disappears around exhausted mines.” For Russia they were of great importance scientific works A. Humboldt (1769 - 1859), German naturalist, foreign honorary member of the St. Petersburg Academy of Sciences (1818), geographer and traveler. Alexander Humboldt received an invitation from Emperor Nicholas I to come to Russia “in view of the great benefits that could result from it for science and the state.” In addition to the Urals and Siberia, A. Humboldt explored the nature of various countries in Europe, Central and South America. He was one of the founders of plant geography and the study of life forms. A. Humboldt substantiated the idea of ​​vertical \^ zoning, laid the foundations of general geoscience and climatology, prepared the main work "Cosmos", which sets out the foundations \^ of his natural philosophical worldview on nature, for example, ^7 shows the history of thinking about the unity of phenomena and interactions -N^ forces in the Universe. It should be noted that the work “Cosmos” NN was a work that aroused in wide sections of the population of various countries the interest and desire to understand the laws of nature. The works of A. Humboldt had a great influence on the development of evolutionary ideas and the comparative method in natural science. A supporter of Humboldt, who had a passion for distant travels and the nature of his native places, was Moscow University professor C. F. Roulier (1814-1858), who was not only a scientist, but also a popularizer of natural science knowledge and evolutionary ideas in Russia, a predecessor of Charles Darwin. In his classic work General Zoology, Roulier argued that nature is eternal; all its phenomena are interconnected and form a single whole. Any living thing depends on external conditions, i.e. from air, water, soil, climate, plants and, finally, from humans. Jean Baptiste Lamarck (1744-1829) was one of the most prominent representatives of French science in the first third of the 19th century. In 1802, Lamarck published his work “Hydrogeology”. It examined natural processes leading to changes on the surface of the globe. (Now we can, of course, add not only natural forces, but also anthropogenic influences.) Lamarck in his work noted the importance of living organisms in natural processes and emphasized the fundamental difference between the organic and inorganic world. Lamarck first coined the term "biology". He came close to the concept of “biosphere”. In 1809, the classic work “Philosophy of Zoology” was published, which brought Lamarck a lot of suffering during his life, especially from the generally recognized authority in science, the French zoologist J. Cuvier (1769-1832), and was recognized only after his death. What are Lamarck's evolutionary views? He proved that individuals of one of the species, changing their place of residence, lifestyle or habits and being influenced, change the composition, proportions and even organization, i.e. individuals belonging to one species by origin end up being transformed into a new species, different from the original, under the influence of environmental factors. No one before Lamarck developed the doctrine of the origin of some species from others and of evolution in the world of animals and plants. His views were evolutionary and ecological. Another great humanist was Wolfgang Goethe (1749-1832) from Germany. Zoology and botany, anatomy and physiology, geology and paleontology, physics and mineralogy - all these sciences were equally interested in Goethe. He created a science, calling it "morphology" or "the science of the formation and transformation of organic bodies." Goethe's hobbies are varied, but love for the world of living nature was a powerful incentive for Goethe in his poetic, philosophical and scientific research. Ecological concepts One can name his statements about the growth and development of plants, about the modification of leaves under the influence of light, heat and moisture. Goethe lived and worked during the heyday of the philosophy of I. Kant, F. Schelling (1754-1854), F. Hegel (1770-1831). However, Goethe's natural philosophical worldview was deeply original. He had a deep faith in the power of natural science, capable of penetrating the most intimate secrets of nature. The English naturalist Charles Darwin (1809-1882), like Alexander Humboldt, was a forerunner of modern geography and ecology. According to Darwin, every organism has constant connections not only with the conditions of its habitat, but also with all the creatures around it. It seems to bear the imprint of the entire environment. From this double dependence of organisms, two types of adaptation arise: to abiotic conditions (the nature of the soil, climate and other factors) and biotic (coexistence with other organisms). The teaching had a deep evolutionary meaning, pointing to the possibility of the origin of organisms and plants from the simplest forms. This approach to Darwin's research gave rise to the German scientist E. Haeckel (1834-1919) to declare the advisability of identifying a new science - ecology - the science of the relationships of living organisms and the communities they form with each other and with the environment. Ecology as an independent science was formed by the beginning of the 20th century, when in 1901 the Danish botanist J. Warming (1841 -1924) first used this term in the modern sense in the publication “Oncological Geography of Plants”. Among the biologists and geographers of Russia in the pre-revolutionary years, one can name such outstanding scientists as I. P. Pavlov (1849-1936), K. A. Timiryazev (1843-1920), A. N. Severtsov (1866-1936), V. .L. Komarov (1869-1945), N. M. Knipovich (1862-1939), V. N. Sukachev (1880-1967), L. S. Berg (1876-1950), G. F. Morozov (1867-1920) , G.N. Vysotsky (1865-1940), etc. Among them is the naturalist V.I. Vernadsky (1863 - 1945), who played a special role in the development of the doctrine of the biosphere - the shell of the Earth. According to him, the biosphere is a planetary phenomenon of a cosmic nature. The entire biosphere is permeated by the interaction of not only terrestrial, but also cosmic bodies and phenomena. And the main role among them is played by living organisms, the “living substances” of the planet. “The biosphere,” noted Vernadsky, “can be considered as a region of the earth’s crust occupied by transformers that convert cosmic radiation into earthly energy; The rays of the sun determine the main features of the mechanism of the biosphere.” Thus, when defining the biosphere, Vernadsky introduces the concept of “living matter” - this is the totality of all living organisms. The distribution area of ​​living matter includes Bottom part the air shell (atmosphere), the entire water shell (hydrosphere) and the upper part of the solid shell (lithosphere). Understanding of V.I. Vernadsky’s ideas came only in the 1960s. It seemed to grow stronger as humanity realized the threat of an environmental crisis. Therefore, solving global environmental problems is impossible without knowledge of the laws governing living organisms in the biosphere. In his works V.I. Vernadsky emphasized the dominant role of the human factor in the development and preservation of the biosphere, which is confirmed (in recent decades) by the emergence of a number of environmental problems on a global scale. The words of the founder of the doctrine of the biosphere sound like a reminder: “The biosphere is the environment of our life, this is the “nature” that surrounds us, which we talk about in colloquial language. Man, first of all, through his breathing and the manifestation of his functions, is inextricably linked with this “nature,” even if he lives in a city or in a secluded house.” A huge contribution to the improvement and development of environmental problems in the last decade of the 20th century. contributed by organic chemist Academician of the Russian Academy of Sciences Valentin Afanasyevich Koptyug (1931 - 1997). He was also the vice-president of the USSR Academy of Sciences from 1979 (then the Russian Academy of Sciences from 1991), and from 1980 the chairman of the Siberian branch of the Academy of Sciences. And after his death he left a huge legacy, including works on environmental issues. V. A. Koptyug focused his main attention on preserving the unique natural Lake Baikal, and participated in the examination of a number of projects, including the construction project of the Katunskaya hydroelectric power station in Altai. Let us remember the Russian thinker of the late 20th century. - L.M. Leonov (1899-1994), what is his relation to the protection of nature and the environment. Leonov, a famous classic of Russian literature, spoke about the catastrophe threatening humanity. The last novel-obsession “Pyramid” was dictated by his premonition about that catastrophe, whose approach had long worried him. The depth of social and moral-philosophical issues led Leonov to the conclusion that “our current situation in Russia and other countries, caused by the claims of senseless national pride, and flared up on a sixth of the land, which literally has always been a single country, should become instructive for those still prosperous while separate peoples... the supposedly brilliant, but in reality infinitely fragile spiritual and material civilization today is too reminiscent of Belshazzar’s feast”1. And the ominous, incomprehensible words that at one time predicted death: “mene, tekel, uparsil! are already on fire"; this is a fatal warning to our settled community, a warning against an impending disaster. L. Leonov named these signs. A scientific forecast promises that in 2200, if the demographic process continues as it is now, the population on planet Earth will be 260 billion people, “which could be more dangerous than mutual bitterness and explosive hostility between them.” Let's also add uncontrollability and non-compliance with environmental laws. The environmental problem in Russia is dealt with not only by scientists and specialists from relevant organizations (for example, the Ecograd Research Center, the Research Center for Environmental Safety of the Russian Academy of Sciences, the Research Institute for Atmospheric Air Protection of the Russian Federation, etc.), but also trade unions and regional ( city) authorities.

Most of the world's population lives in cities, resulting in congestion in urban areas. At the moment, it is worth noting the following trends for city residents:

• deterioration of living conditions;
• increase in diseases;
• decline in human productivity;
• decreased life expectancy;
• climate change.

If you add up all the problems of modern cities, the list will be endless. Let us designate the most critical cities.

Change in terrain

As a result of urbanization, there is significant pressure on the lithosphere. This leads to changes in topography, the formation of karst voids, and disruption of river basins. In addition, desertification occurs in areas that become unsuitable for life of plants, animals and people.

Degradation of the natural landscape

Intensive destruction of flora and fauna occurs, their diversity decreases, and a unique “urban” nature emerges. The number of natural and recreational areas and green spaces is decreasing. The negative impact comes from cars that crowd urban and suburban transport routes.

Water supply problems

Rivers and lakes are polluted by industrial and domestic wastewater. All this leads to a reduction in water areas and the extinction of river plants and animals. All the planet's water resources are being polluted: groundwater, inland hydraulic systems, and the World Ocean as a whole. One of the consequences is the shortage of drinking water, which also leads to the death of thousands of people on the planet.

This is one of the first environmental problems that were discovered by mankind. The atmosphere is polluted by car exhaust gases and emissions from industrial enterprises. All this leads to dusty atmosphere. In the future, dirty air becomes the cause of diseases in people and animals. As forests are being intensively cut down, the number of plants on the planet that process carbon dioxide is decreasing.

Household waste problem

Garbage is another source of soil, water, and air pollution. Various materials are processed over a long period of time. The decay of individual elements takes 200-500 years. And while the processing process is underway, harmful substances are released that cause diseases.

There are other environmental problems of cities. No less relevant are the problems of the functioning of urban networks. These problems should be resolved by top level, but small steps can be taken by people themselves. For example, throwing garbage into the trash can, saving water, using reusable dishes, planting plants.

It is often believed that the environmental condition of cities has noticeably deteriorated in recent decades as a result of the rapid development of industrial production. But this is a misconception. Environmental problems of cities arose along with their birth. The cities of the ancient world were characterized by a very crowded population. For example, in Alexandria the population density in the 1st–2nd centuries. reached 760 people, in Rome - 1,500 people per 1 hectare (for comparison, let’s say that in the center of modern New York no more than 1 thousand people live per 1 hectare). The width of streets in Rome did not exceed 1.5–4 m, in Babylon – 1.5–3 m. The sanitary improvement of cities was at an extremely low level. All this led to frequent outbreaks of epidemics, pandemics, in which diseases covered the entire country, or even several neighboring countries. The first recorded plague pandemic (known in literature as the “Plague of Justinian”) occurred in the 6th century. in the Eastern Roman Empire and covered many countries of the world. Over 50 years, the plague claimed about 100 million human lives.

Now it is difficult to even imagine how ancient cities with their many thousands of people could manage without public transport, without street lighting, without sewerage and other elements of urban amenities. And, probably, it is no coincidence that it was at that time that many philosophers began to have doubts about the advisability of the existence of large cities. Aristotle, Plato, Hippodamus of Miletus, and later Vitruvius repeatedly came out with treatises that addressed issues of the optimal size of settlements and their structure, problems of planning, construction art, architecture, and even the relationship with the natural environment.

Medieval cities were already significantly smaller in size than their classical counterparts and rarely numbered more than several tens of thousands of inhabitants. Thus, in the 14th century. the population of the largest European cities - London and Paris - was 100 and 30 thousand inhabitants, respectively. However, urban environmental problems have not become less acute. Epidemics continued to be the main scourge. The second plague pandemic, the Black Death, broke out in the 14th century. and killed almost a third of Europe's population.

With the development of industry, rapidly growing capitalist cities quickly surpassed the population of their predecessors. In 1850, London crossed the million mark, then Paris. By the beginning of the 20th century. there were already 12 “millionaire” cities in the world (including two in Russia). The growth of large cities proceeded at an ever faster pace. And again, as the most formidable manifestation of the disharmony between man and nature, outbreaks of epidemics of dysentery, cholera, and typhoid fever began one after another. The rivers in the cities were terribly polluted. The Thames in London began to be called the “black river”. Fetid streams and ponds in other large cities became sources of gastrointestinal epidemics. Thus, in 1837, in London, Glasgow and Edinburgh, a tenth of the population fell ill with typhoid fever and approximately a third of patients died. From 1817 to 1926, six cholera pandemics were recorded in Europe. In Russia, in 1848 alone, about 700 thousand people died from cholera. However, over time, thanks to the achievements of science and technology, advances in biology and medicine, and the development of water supply and sewerage systems, the epidemiological danger began to weaken significantly. We can say that at that stage the environmental crisis of large cities was overcome. Of course, such overcoming each time cost colossal efforts and sacrifices, but the collective intelligence, perseverance and ingenuity of people always turned out to be stronger than the crisis situations they themselves created.

Scientific and technical achievements based on outstanding natural scientific discoveries of the 20th century. contributed to the rapid development of productive forces. This is not only the enormous successes of nuclear physics, molecular biology, chemistry, and space exploration, but also the rapid, continuous growth in the number of large cities and urban population. The volume of industrial production has increased hundreds and thousands of times, the power supply of humanity has increased more than 1000 times, the speed of movement has increased by 400 times, the speed of information transfer has increased by millions of times, etc. Such active human activity, of course, does not pass without a trace on nature , since resources are drawn directly from the biosphere

And this is only one side of the environmental problems of a big city. Another is that in addition to consuming natural resources and energy drawn from vast spaces, a modern city with a million people produces a huge amount of waste. Such a city annually emits into the atmosphere at least 10–11 million tons of water vapor, 1.5–2 million tons of dust, 1.5 million tons of carbon monoxide, 0.25 million tons of sulfur dioxide, 0.3 million tons of nitrogen oxides and a large the amount of other pollution that is not indifferent to human health and the environment. In terms of the scale of its impact on the atmosphere, a modern city can be compared to a volcano.

What are the features of the current environmental problems of large cities? First of all, there are numerous sources of environmental impact and their scale. Industry and transport - and these are hundreds of large enterprises, hundreds of thousands or even millions of vehicles - are the main culprits of pollution of the urban environment. The nature of waste has also changed in our time. Previously, almost all waste was of natural origin (bones, wool, natural fabrics, wood, paper, manure, etc.), and they were easily included in the cycle of nature. Nowadays, a significant part of waste is synthetic substances. Their transformation in natural conditions occurs extremely slowly.

One of the environmental problems is associated with the intensive growth of non-traditional “pollution”, which has a wave nature. The electromagnetic fields of high voltage power lines, radio broadcasting and television stations, as well as a large number of electric motors are increasing. The overall level of acoustic noise increases (due to high transport speeds, due to the operation of various mechanisms and machines). Ultraviolet radiation, on the contrary, decreases (due to air pollution). Energy costs per unit area increase, and, consequently, heat transfer and thermal pollution increase. Under the influence of the huge masses of multi-story buildings, the properties of the geological rocks on which the city stands change.

The consequences of such phenomena for people and the environment have not yet been sufficiently studied. But they are no less dangerous than pollution of water and air basins and soil and vegetation cover. For residents of large cities, all this together results in a great overstrain of the nervous system. City dwellers get tired quickly, are susceptible to various diseases and neuroses, and suffer from increased irritability. Chronically poor health of a significant part of urban residents in some Western countries is considered a specific disease. It was called "urbanite".