10 000 знаков / Экология ( без перевода)

Environmental problems / Проблемы окружающей среды

All the nations have the same basic environmental problems. In fact the problem of environment crisis has assumed a global proportions. That is why many ecological problems can generally be solved only at the world community level. As nations we all share a single ecological space. Acid rains, for example, have no boundaries. Nuclear radiation does not respect administrative or national regions. All the nations must assume a position as responsible members of the world community level, cooperating in matters of environmental protection. It’s important that we all work together to share, to overcome ecological disasters. Both scientists and politicians agree that if some radical steps are not taken, life on our planet may be damaged if not destroyed altogether, because the number of air pollutants is constantly growing. Ecological disasters do not happen by chance. Ignorance, lack of planning, greed and criminal neglect have been responsible for creating ecological distress zones throughout the world. Radioactive materials present health and safety problems in an increasing number of countries. Underground nuclear-weapon tests are a major threat to the environment. Steps must be taken to do away with nuclear tests. The acid falls to earth in form of rain or snow that can damage anything from the monuments to living organisms. The increase in traffic is threatening another serious air pollution in our cities, because vehicles, not factories, produce most of toxic micro-particles, which do most harm. Toxic gases appear in the atmosphere in critical concentration of carbon dioxide is expected to increase at rates that could change the world’s climate. The commonest air pollution comes from the cigarette smoke, which pollutes public places. Water pollution is another important problem. In several years tourists will find fewer beaches where it’s safe to swim. Urgent measures must be taken if we don’t want to leave a dangerous planet to future generations.

Animals need help. Earth is in danger / Животным нужна помощь. Земля в опасности

People have lived on our planet for many years. They lived and live on different continents, in different countries. People depend on their planet, on the sun, on animals and plants around them. People must take care of Earth. Our ecology becomes worse and worse with every new day. Many species of animals and birds are disappearing nowadays. People destruct wildlife, cut down trees to make furniture. They forget that people can’t live without trees and plants, because they fill air with oxygen. And, of course, great problems are population and animals destruction. The main reason of pollution is rubbish. Most of our rubbish goes to big holes in the ground, called ‘dumps’. But dumps are very dangerous for our life ‘cause they are full of rats, which can carry infections away from dumps. Another way to get rid of rubbish is to burn it. But the fires make poisons, which go into the air and pollute it. But pollution isn’t the only actual problem. Every day a big number of animals dissapeares. People kill animals for different aims: people hunt whales for their meat and oil; elephants for their tusks, crocodiles for their leather and so on. And also animals are used for medical experiments. Modern life is bad for animals, birds, fish. The air isn’t fresh and the water isn’t pure. They don’t have good meal and facilities for the life. You can find their names in the Red Book. Of course, people can’t stay indifferent to these problems. There are a lot of special organizations, which try to save our nature. The most known are: The Royal Society for the prevention of cruelty to animals (The RSPCA), the World Wildlife Fund (WWF) and Greenpeace. The RSPCA tries to protect animals from bad use. It operates big nation campaigns aimed at lost pets, circus animals. The WWF rescued several species of animals, mammals as well as birds. These organization also helped to create more than 250 National parks. Greenpeace began its work 20 years ago from saving whales. And now Greenpeace is a world-famous organization, which saves plants, animals and people. These organization, want to rescue animals, to help them to survive and to save jungle rain forests, which are in danger of destruction. We must lake care of nature, because we are part of it.

Environment and ecology / Окружающая среда и экология

The poisoning of the world's land, air, and water is the fastest-spreading disease of civilisation. It probably produces fewer headlines than wars, earthquakes and floods, but it is potentially one of history's greatest dangers to human life on earth. If present trends continue for the next several decades, our planet will become uninhabitable. Overpopulation, pollution and energy consumption have created such planet-wide problems as massive deforestation, ozone depletion, acid rains and the global warming that is believed to be coused by the greenhouse effect. The seas are in danger. They are filled with poison: industrial and nuclear waste, chemical fertilisers and pesticides. The Mediterranean is already nearly dead; the North Sea is following. The Aral Sea is on the brink of extinction. If nothing is done about it, one day nothing will be able to live in the seas. Every ten minutes one kind of enimal, plant or insect dies out for ever.

Ecological problems / Экологические проблемы

Since ancient times nature has served man, being the source of his life. For thousands of years people lived in harmony with environment and it seemed to them that natural riches were unlimited. But with the development of civilization man's interference in nature began to increase. Large cities with thousands of smoky industrial enterprises have appeared all over the world today. The byproduct of their activity pollutes the air we breathe, the water we drink, the land we grow grain and vegetables. Every year world industry pollutes the atmosphere with about 1000 million tons of dust and harmful substances. Many cities suffer from smog. Vast forests are cut and burn in fire. Their disappearance upsets the oxygen balance. As a result some rare species of animals, birds, fish and plants disappear forever, a number of lakes and rivers dry up. The pollution of air and the world's ocean destruction of the ozone layer is the result of man's careless interaction with nature, a sign of ecological crises. As a result of the Chernobyl tragedy the Belarussian people faced the most horrible ecological disaster. About 18 per cent of the territory of Belarus was contaminated with radioactive substances. A great damage has been done to the republic's agriculture, forests and people's health. The consequences of the atomic power station explosion are tragic for the Belarussian nation. Only a small percent of Belarussian land remains contamination are being discovered every year. Not only Chernobyl but many of our "peaceful" factories and towns cause a great damage to the environment. Dangerous dust and blow-outs of the enterprises are being carried out by winds for long distances destroying the life around. People all over the world are worried about what is happening to the environment. They understand that the earth is their home, a big green home. The environment protection should be our universal concern. Some progress has been already made in this direction. As many as 159 countries - members of the UNO have set up environmental protection agencies. Numerous conferences have been held to discuss questions of ecologically poor regions including the Aral Sea, the South Urals, Kuzbass, Donbass, Semipalatsinsk and Chernobyl. An international environmental research center as been set up on Lake Baikal. The international organization Greenpeace is also doing much to preserve the environment. But these are only the initial steps that must be carried forward to protect not only for the sake of the present but for the future generations. Ecological problems.

Ecology / Экология

In recent years the environmental problems have become extremely urgent and received a great publicity. In some way they are the result of scientific and technological progress of the 20-Th century. But people also do a lot of harm to nature because they don't understand that the man is the part of environment. The relationship between man and nature has become one of the most vital problems facing civilization today. Pollution of water and air is one of the problems millions of people are concerned today. Acid rains,of nuclear and hydraulic power stations, radioactive and other poisonous materials, disposal of wastes became the global disasters. Cars are one of the most harmful and dangerous polluters of air. In more than a hundred towns and cities the concentration of harmful substances in the air and water is over 10 times the admissible level. Archangel is one of the most "dirty" towns of the country. The Nothern Dvina - our main water source is fully polluted with industrial and communal wastes - the result of side - effect in the work of three giant pulp and paper mills. Water is not suitable for drinking. Another problem is presence of dangerous radioactive military objects . Besides we must remember about ozone holes over our heads. The ozone layer doesn't protect us from dangerous ultraviolet rays any more. They get through the atmosphere causing skin cancer and other diseases. All these facts make us become more sensitive towards the environment.

RADIOACTIVITY / Радиоактивность

Ernest Rutherford studied the invisible radiations. He discovered that they consisted of two types of charged particles and one type of ray. The negatively charged particles were called beta-particles. They were actually electrons. But what were the other particles? To find out Rutherford carried out more experiments. He discovered that particles, called alpha-particles, were actually positively charged nuclei of helium atoms.

Further study showed that the particles move at tremendous speeds. Alpha-particles travel at 10,000 to 20,000 miles per second. Beta-parti­cles move at even higher speeds. Gamma rays, which travel at the speed of light, were found to be similar to X rays. Gamma rays have the greatest penetrating power of the three types of radiations. Ordinary aluminum foil can stop alpha-particles, but it requires an aluminum sheet 1 centimeter thick to stop beta-particles. The gamma rays, given off by unstable atomic nuclei, have a penetrating power which is 10,000 times greater than of alpha-particles.

A number of natural elements and all transuranium elements are naturally radioactive. People who work with radioactive materials must have special protection because radiation exposure can damage body tissues. Special badges, containing photographic film sensitive to radiations, are worn. The film is examined at regular intervals to determine the amount of radiation to which the people have been ex­posed. This is a safety measure to prevent harmful effects of radiation.

Radioactive elements lose mass as they give off particles and rays. At first, it was thought that a radioactive element would continue to produce the same amounts of energy forever. However, it was later discovered that a radioactive element loses mass. This could only mean that the nucleus of the radioactive element was undergoing change. Every radioactive element breaks down at a certain rate that is charac­teristic for it. This decay rate for the radioactive elements is described in terms of the half-life of an element. Half-life is the time it takes for one-half of the atoms of a radioactive element to decay.

Radium, for example, has a half-life of 1600 years. That means that 50 per cent of all the atoms in a given amount of radium will break down in 1600 years. Then, half of the remaining radium atoms will break down in the next 1600 years, and so on. The nuclear decay continues until all the radium atoms have changed into stable lead atoms. Some radioactive elements have a half-life of thousands of years. Others have a half-life measured in minutes or seconds.

Radioactivity can be detected with special instruments. Particles and rays given off by radioactive elements may cause the uncharged atoms of a gas through which they pass to become electrically charged. An atom that becomes electrically charged is known as an ion. An ion has properties different from those of uncharged atoms. The atoms of a gas may become either positively or negatively charged. This depends on whether the radioactive particles remove or add electrons from the atoms. This process in which the atoms of a gas become electrically charged is called ionization.

When radiations pass through an instrument, called a cloud cham­ber, they produce streams of ionized atoms. These attract molecules of the surrounding gas, causing them to condense into visible fog trails. By counting the number, of tiny droplets in each track, scientists have determined the speed of the radioactive particles.