Air Pollution

Pollution is of great concern to both science, industry and to humanity as a whole.

There has always been pollution, even when man was not present. When man appeared upon earth, he added much to the pollution through the industrial activity, and through man's use of devices such as automobiles that cause pollution.

Every smoking chimney is a source of air pollution. The use of natural gas or oil that have a negligible mineral content is of great help in reducing pollution, but has the disadvantage of rapidly consuming materials which could better be conserved for future generation as raw materials for the manufacture, for example, chemicals and plastics.

It has been found that some chemical processes, such as the manufacture of lime, Portland cement, steel, give off much dust.

Lead, bromide and chloride are emitted by the automobiles which burn lead-containing gasoline. A lead-chloride-bromide aerosol is exhausted in great amounts nowadays.It is considered to be a common air contaminant in urban areas. It has been long found out that such aerosol is toxic to people and has prolonged negative effect as it’s hardly taken out from the organism.

The oxides of sulphur, oxides of nitrogen, carbon monoxide as well as incompletely burned hydrocarbons are included to the group of chief atmospheric gaseous pollutants.

It is stated that these gases react with energy from sunlight and produce photochemical smog. Smog not only can be highly irritating to eyes and lungs, but it can also cause extensive damage to vegetation.

City air is polluted not only by exhaust fumes but also by the products of their oxidization, often much more toxic than the initial substance. One of them is ozone which is useful only in small quantities, but is deadly poisonous in large concentrations.

10. Answer the following questions:

1. When did pollution appear? 2. When did pollution increase? 3. Why did pollution increase? 4. What sources of air pollution do you know? 5. Where does much dust come from? 6. What compounds are considered to be the chief atmospheric gaseous pollutants? 7. What is photochemical smog? 8. What can smog cause? 9. What is much more toxic than the initial substance? 10. Is it possible to achieve a progress in preventing cities from pollution?

11. Find in the text the English equvalents of the following words and word combinations:

будущее поколение; источник загрязнения; сырье; незначительное содержание; и малых количествах; в высокой концентрации; сокращение загрязнения; недостаток; потребляемые материалы; улучшать; вредный; следует отметить; продукты окисления; исходные вещества; в огромных количествах; считается, что; установлено, что; давно выяснено, что; известно, что;.

12. Retell the text, using the phrases like “it is stated”, “it is known”, “it has been found out that” and so on.

Дата добавления: 2015-12-01