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TEXT 17 RECULTIVATION OF LAND





Efforts are being undertaken throughout the world to recultivate the lands spoiled by industry. Recultivalion develops along the following lines depending on the subsequent use to be made of the land:

1. Agriculture: ploughland, meadows, pastures and perennial crops.

2. Forestry: forestation for exploitation and special purposes (soil conservation, sanitary purposes, water protection and so on).

3. Water economy (reservoirs, fish and waterfowl ponds and so forth).

4. Recreation: parks, swimming pools, beaches and the like.

5. Architecture and urban planning: planting of trees, shrubs and lawns, making of ponds in depressions near housing.

In all cases, recultivation is carried out in two stages: the technical stage constitutes the process of constructing the land areas, and the biological stage aimed at putting the land to use.

The technical stage should include the leveling of open-cut mines and pits, chemical improvement (when the rock is phototoxic), and covering the rock with a layer of fertile soil. The fertile soil layer is of decisive importance in securing plant growth. That is why it is vital not to destroy the top soil on the areas to be mined or on construction sites.

The biological stage includes the growing of greenery: the restoration of forests or agricultural fields, the planning of parks, the breeding of fish in ponds and so on. In scarcely populated areas recultivalion is carried out by planting forests more often. That is because forest plants are less demanding on the environmental conditions than agricultural crops. When forests are planted, the surface does not have to be so carefully leveled and the layer of fertile soil does not have to be so thick. This makes the work simpler and less costly.

Agricultural recultivation is usually carried out in agrarian areas with dense population, fertile soils and where the shortage of land is particularly felt.

TEXT 18 CHORNOBYL ACCIDENT, ITS CONSEQUENCES
AND LESSONS

The 26th of April is a bitter event for the people living in Ukraine and regions situated far from it. On that day in 1986 a horrible accident occurred at the Ghornobyl nuclear power station. There was the explosion of reactor of the fourth power unit. This explosion resulted in hazardous nuclear contamination of air, soil, water. Thanks to urgent and brave actions of firemen, the fire was stopped.

A number of foreign countries offered specialized medical equipment and drugs for biological elimination of isotopes of different chemical elements from human body. Later on thousands of children were taken abroad for corresponding medical treatment.

Such accidents like that in Chernobyl must never be repeated again, because the very existence of millions of people may be under a threat. This accident will never be forgotten.

From the distance we passed we look back at the tragic explosion of the reactor and long ejections of radioactive iodine, cesium, strontium, plutonium and other isotopes, ejections which in their sum are equal, as scientists consider, to at least five hundred Hiroshima bombs... About 300 mln curies of radionuclides which covered only in Ukraine of almost 95 % of its territory were ejected in our sky.

Over 90 thousand persons from 76 villages were evacuated within the first two months from the 30-kilometer zone. Now this zone is called as the Zone of estrangement, and now just in this zone are concentrated the most complicated scientific-engineering problems.

Of real potential threat for the population and environment in the water meadow of the Prypyat-river, where, in accordance with our estimates, there are over 14 thousand curies of radioactivity of strontium-90, and the threat lies in the fact that in case of high flood or strong rains the radionuclides may be flooded down into the Dniper-river, whose waters are used by 32 mln people of Ukraine. Therefore, main efforts here are directed at prevention of radionuclides spreading beyond the borders of the Zone of estrangement, prevention of their migration.

To make the life of population safer, desactivation and cleaning of the territories is being carried out, and an anti-flood dam was constructed.

Over 142 thousand people have been resettled from the contaminated territories or left these territories themselves. 123 hectares of agricultural lands and 157 hectares of forests have been extracted from usage. 570 artesian wells were made, hundreds of kilometers of water lines were laid, highways with hard covering were made. Maps of radioactive contamination have been compiled.

In order to implement the state policy of liquidation of consequences of the Chernobyl catastrophe and protection of people against their influence was established the State Committee for protection of population against consequences of the Chornobyl catastrophe, which in May of 1991 was transformed into the Ministry for protection of population against consequences of the Chornobyl catastrophe.

Now, when years passed from the moment of that tragic event, the external ionizing irradiation is not of such large danger as before, but, first of all, of great importance becomes the so-called internal irradiation with the isotopes, brought into the body of man with contaminated foodstuffs.

Enormous material and financial resources were required in the first years and are required now to overcome consequences of the catastrophe and minimize them.

Ukraine spends annually for minimization of consequences of the Chernobyl catastrophe and for social protection of victims about 6 percent of its budget, i.e. the sum which exceeds 800 mln US dollars.

The understanding of the fact that negative influence of Chernobyl will be long and its minimization will require coordinated efforts of many ministries and departments, scientific institutions, bodies of the executive power in cities prompted the necessity of development of the long-term National program of liquidation of consequence of the Chornobyl catastrophe and social protection of citizens-victims of the catastrophe.

If we speak about its main aspects and objectives, they are the following:

– reduction of risk of deterioration of the health of population that suffered from the Chornobyl catastrophe;

– rehabilitation of the territories contaminated with radionuclides in the zone of compulsory re-settling and return of them into general economic usage;

– fulfillment of protective measures on the Zone of estrangement in order to avoid the spread of radionuclides beyond its borders, stabilization of the «Cover» object;

– improvement of socio-economic conditions for the population living in contaminated territories.

Chornobyl nuclear catastrophe has no analogues in the world. Therefore, it is not strange that it attracted attention of the world community. Actually, in the first years after the catastrophe our Republic had rather weak contact with the world. And only after independence was proclaimed in Ukraine, direct contacts with various international organizations and separate countries along the Chornobyl line became active. Thus, in 1995 about 50 international projects and programs connected with study and minimization of the catastrophe consequences were underway. Speaking about the international cooperation it is necessary to mention, first of all, the UN and such bodies of it as UNESCO and others. Fruitful is the co-operation with the European Commission, as well as with separate countries – with the USA, Japan, Germany, Sweden, Canada, Cuba – it is impossible to mention all the countries.

We want to believe that the world community will remember in the future about the problems which were caused by the Chornobyl catastrophe; it will develop cooperation concerning the study and minimization of action of radioactive contamination.

In this aspect very important for us will be such directions as protection of the population health, rehabilitation of contaminated territories, establishment of a system of treatment of radioactive wastes, solving the problem of the «Cover» object. The whole knot of ecological problems being of interest for specialists is concentrated in the Zone of estrangement; these problems should be solved. This is the purpose of the Chornobyl centre for problems of nuclear safety, radioactive wastes and radioecology with the status of the international centre which was established in accordance with the Decree of the President of Ukraine L. Kuchma of the 26th of April, 1996.

There are many points for close cooperation, the result of which will serve for the whole mankind.

TEXT 19 AIR POLLUTION

1. In fact, some of the major environmental problems of our time – acid rain, ozone depletion, and the possibility of global climate change, among them – all result from air pollution.

2. Coal, oil, and other fossil fuels are the source of power behind a lot of what we do every day. These fuels generate most of the energy used throughout the industrialized world.

Unfortunately, they also generate most of the world’s air pollution. That's because we burn fossil fuels to get the energy out of them. And this combustion process creates a lot of waste, much of it in the form of toxic gases.

3. Carbon monoxide, carbon dioxide, nitrogen oxides, and sulphur dioxide are some of the most dangerous gases produced during fossil fuel combustion. Of these, carbon monoxide is the most directly harmful to life because it’s poisonous in very small amounts and it’s produced in huge concentrations. In contrasts, carbon monoxide’s «cousin», carbon dioxide (CO2), is relatively nontoxic. But it plays a key role in the greenhouse effect by trapping heat rather than allowing it to escape into space. The other oxides – sulphur oxide and nitrogen oxides – become most dangerous when they combine with other substances creating problems such as smog and acid rains.

4. Gases are not the only air pollutants resulting from fossil fuel combustion. Tiny bits of dust, metal soot, and other materials, called particulates, also find their way into the atmosphere from sources such as diesel engines and power plants. Particulates can cause respiratory diseases, cancer, and other health problems. Fossil fuel combustion spews out plenty of particulates, but there are also many other sources of these pollutants. For example, construction projects can kick up a lot of dust. And woodburning stoves and fire places can produce large amounts of smoke and ash (not to mention carbon dioxide and other gases). So can the burning of tropical forests.

5. It’s not just what gets dumped into the air that causes problems; it’s also how the individual pollutants interact with each other, water, and / or sunlight. And sometimes pollutants interact with atmospheric conditions creating problems that, at first glance, might not seem to have much to do with polluted air. Acid rain is one result of «interactive» pollution. It starts with fossil fuel combustion mostly from power plants and cars. Sulphur dioxide, originating mainly from coalburning power plants, and nitrogen oxides, from both power plants and cars, are the gases at fault. Once in the air, these gases combine with water droplets and form sulphur and nitric acids. The acid can fall as rain or snow, or they can hover near the ground as a fog. Acid rain can even fall to earth as dry particles. Although many people use «acid rain» to refer to both wet and dry acid precipitation, some scientists prefer the term «acid deposition».

6. Fifteen to twenty miles above the earth’s surface, ozone occurs naturally in a zone of the atmosphere called the stratosphere, where it blocks out harmful ultraviolet (UV) rays from the Sun. Ironically, though, certain human-caused pollutants react with this «good ozone», causing it to break down. The gases called chlorofluorocarbons, or CFCs, are the main culprits. Unlike most other major sources of air pollution, CFCs are not formed from the combustion of fossil fuels.

There’re used as cooling agents in refrigerators and air conditioners and as propellants in certain products sold as sprays. They’re also used in the production of some polystyrene foam products, such as Styrofoam. But when CFCs get into the atmosphere they «attack» the ozone layer. The result is ozone depletion.

7. CFC is dangerous to the atmosphere in more ways than one. Besides destroying ozone, they also play a role in the greenhouse effect – a natural process in which certain gases acting like the glass walls that allow the sun's radiation in and then keep the heat it produces from getting out. Under normal circumstances this phenomenon wouldn't be a problem (in fact, it keeps the Earth from getting too cold to sustain life). But because people are adding more greenhouse gases to the atmosphere than occur there naturally, many scientists are concerned that we may be drastically changing the atmosphere’s chemistry.







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