The Town of the XXI Century
Series of reports on ecological situation in Central Asia

CITIES ARE ADVANCING ALL OVER THE PLANET

Within next 30 years the population of our planet will supposedly grow by two thirds: from 5,5 billion people to 8,5 billion. Out of these 8,5 billion about 7,1 billion will live in developing countries and mainly in the cities. At the same time it is projected that the population of developed countries, currently reaching 1,2 billion people will grow to only 1,4 billion by the year 2025. And there are the reasons to suggest that the main part of the growth will take place in the United States of America.

Currently three fourth of citizens of developed countries live in cities, in developing countries this figure is one third.

The rate of growth of the part of the world's population living in cities is much higher than the overall natural increase in the planet's population. There are many reasons explaining this trend and one of the most important ones - opportunities for an easier life than in rural areas. In cities people have more opportunities to find jobs and have higher incomes, people have easier access to education and medical services. Generally life in cities is much easier than in rural areas.

PROHIECES OF THE GREAT DUKE ARE COMING TRUE

For example, in 19^th century Lev Tolstoi wrote that in cities people will be dying because of heavy work at steaming factories, that the most healthy life is associated with the countryside and with the healthy labor of a villager, who works breathing clean air of freedom. It seems that there was some truth in the words of the great duke. Really, in the cities air is poisoned by industrial steams, exhaust gases coming from automobiles. Annually significant amounts of ashes, dust, various amalgamations of metals, gas-like substances containing sulphur and hydrogen, are thrown into the air of cities. Consequences resulting from air pollution are numerous. The following ones can be particularly stressed:
 

• Harmful influence on the health of the people and animals;
• Harmful influence on growth of plants;
• Destruction of fixed assets - buildings, metal constructions, vehicles are damaged because of pollution and corrosion;
• Interference with operations of some industries and losses resulting from increased concentration of some substances
• Unpleasant feeling appearing because of thick and sometimes harmful layers of smog and fumes, which interfere with the sun rays.

HERE ARE SOME EXAMPLES OF THE HARMFUL INFLUENCE OF CITIES ON THE ENVIRONMENT

• It has been determined that the terms of exploitation of zinc-covered roofs are 6-7 times shorter in polluted environment. In rural areas wires serve for 50-60 years, while in industrial districts this term is reduced to 5-6 years. In cities the term of exploitation of an average dress is reduced by 5-10%. People living in cities have to wash their clothes and use dry cleaning more often.
• In Rome for tourists it is not all that easy to reach the famous Collesseum During rush hours cars stand around the building straight behind each other, poisoning the air by exhaust gases. The "fathers" of the eternal city worried by the fact that nitrogen oxides, lead and hydrogen oxides can damage the ruins, which have been standing for centuries, are trying to invent various measures preventing drivers from arriving at the site during rush hours. Particularly, the routes of public transportation are changed to decrease the traffic intensity.
• In Paris traffic jams can force you to be a couple of hours later for a business meeting. In these circumstances it is useless to worry or quarrel with the police; this will not make the jam any smaller.
• In Tokyo it is often possible to see people wearing pieces of cloth covering their faces. People living in Tokyo know well enough what the city smog means and that is why they try to wear something like gas-masks.
• Oxide smog filled with the products of reaction among nitrogen oxides and non-burned carbons, arriving in the atmosphere from the exhaust tubes of vehicles, can cause serious inflammation of eyes - hyperimia of the connecting layer of the eye. For example, in Los Angeles serious cases of inflammation were registered among people, who are especially sensitive to these kinds of pollution.
• Acid rains do not represent a new physical event. This term was first used by the English chemist, Mr. Robert Smith, who described the pollution of Manchester in the 19^th century. The new aspect of the event is that it has been recognized as a worldwide problem. Currently air basins of such cities as Manchester are much cleaner because now power plants and industrial installations are equipped with powerful tubes capable of throwing polluting substances high into the atmosphere. However, in general the high tubes just worsened the situation and allowed it to grow into an international problem: mixtures of sulphur and nitrogen developing when the fuel is burned, can be moved away for thousands of kilometers and can cause the fall of acid rains in countries situated far away from the source of pollution.

HOWEVER, THE CITY "POISONS" NOT ONLY THE ATMOSPHERE; IT ALSO AFFECTS RIVERS AND LAKES, LAYING IN THE ZONE OF ITS INTERESTS, IT INFLUENCES FORESTS, WHICH HAPPENED TO BE NEAR THE CITY.

Currently the influence of large city conglomerates is felt by the environment even far away from the city centers. London, Paris, Mexico City, Amsterdam, Los Angeles and many other large cities invade the surrounding fields and turn them into endless "stone jungles". Their steel and concrete tubes have been stretched for many kilometers pumping water from remote rivers and lakes. In cities themselves the plants have almost disappeared; green grass, bushes and trees were replaced by blacktop, concrete and huge blocks of buildings.

Sewage cleaning installations are usually created at the first stage of development of any city. Mistakes of architects or the incorrect selection of the construction spot may result in pollution of the water horizon of the soil. Intrusion of polluted wastes into the underground waters may start epidemics of cholera and other diseases.

The next stage of the city development is usually associated with construction of more fundamental buildings requiring the increase in the volume of land work destroying the upper layers of soils and small bodies of water, which are gradually filled by dumped soil. As a consequence, soil erosion becomes stronger and more soil and sand are accumulated in rivers. The city is growing and covering new and new territories by the water-proof shield, denying access to the underground waters and increasing water levels in remaining rivers, which raises the probability of flooding.

The second stage of the city development, as a rule, introduces the most significant threat to the health of the people - drain of chemicals and non-cleaned sewage into surrounding bodies of water, which leads not only to pollution of the bodies of water, but also to deaths of all organisms living in the water.

The final stage of urban growth is characterized by coverage of all empty land spots by buildings, highways, and other constructions, preventing access of moisture into the soil, which results in interference with water supply of the underground waters and in the increased drainage of rain waters. Higher levels of deep pumping out of underground waters may also lead to the falls of soil. In Texas, the city of Houston located at the shore, is currently facing the problem of 3 meter deep land fall in the radius of 64 km from the center of the city, which was caused by huge volumes of pumped out underground waters. Let us concentrate our attention more closely on the Chinese experience. The largest Asian country is, probably, facing the problems of growing cities on a bigger scale, than other countries, which is explained by the fact that China is the most densely populated country on the planet. For example, in China coal serves as the main source of energy and this, naturally, finds its reflection in the health of the people. In some cities located in the north of the country, such as Beijing and Shanjan, air pollution is worsened by such conditions as weak intermixture of air and low temperature inversions. In this region city centers have the highest levels of sulphur dioxide.

Coal is not the only source of weighed particles. They are also brought from the Gobi desert. In the north of China acid rains caused by high levels of sulphur dioxide concentration do not have any significant negative impacts on the health of the people since the are neutralized by the salt particles brought from the desert. At the same time, for southern regions of China acid rains are turning into a major problem. In this regions several cities register annualized average pH level at 4-4,5, which almost reaches the levels registered in Europe and North America, which suffer the most from acid rains and snows.

In 1992 SO₂ exhausts all over the country reached 16,85 million cubic meters.

Burning coal is the main source of particles and SO₂. Other factors, such as vehicle exhausts and dust contribute their shares into the overall picture of air pollution.

Within last 15 years economic development of the county has implanted a strong impression that people in Chinese cities use bicycles as the main mean of transportation. However, strong economic growth have also permitted many people living in cities to purchase cars and motorcycles and there are reasons to state that this trend will develop more and more rapidly. If this growing use of cars is not accompanied by measures aimed at controlling atmospheric pollution, then the situation may lead to increased concentration of sulphur oxides and dioxides, nitrogen oxides and particles of ashes, which will be dissolved in the air.

Air pollution causes development of many diseases and mainly diseases of breathing organs. In China the beginning of 1990s was characterized by the death rate of 162 per one thousand citizens, which is 5 times higher than in the United States.

The price of pollution is quite high. For China, in general, the annual cost of the city air pollution is estimated to be 880 million USD.

In China many rivers, which pass through the cities, are heavily polluted. About 80 percent of the river waters are polluted by such substances, as nitrogen ammonium, flying phenol, organic substances.

In 1992 the volume of sewage waters reached 36,7 billion tons. This figure excludes industrial sewage. If we add the water resources used in industrial production, then this figure will be 23,4 billion tons more.

Drinking water usually used by people living in cities is of poor quality, however, cases of diseases resulting from poor quality of water are limited since the amjority of the people boil the water before drinking.