Study the following materials on different types of pollution and fill in the table which follows

Land pollution involves the deposition on land of solid wastes--e.g., used cars, cans, bottles, plastic containers, paper--that cannot be broken down quickly or, in some instances, cannot be broken down at all by the action of organic or inorganic forces. When such materials become concentrated within any one area, they interfere with organic life.

Methods of disposal other than recycling include ocean dumping, which creates water pollution and destroys marine habitats; landfill, which often requires the availability of low-lying ground and frequently involves the destruction of marshland or swamps that have high biological value; and burning, which increases air pollution. Obviously, none of these methods is entirely satisfactory, although using landfill to create artificial landscapes, which then are covered with soil and planted with various kinds of vegetation, is a possibility that remains to be fully developed.

Land pollution also involves the accumulation on land of substances in dispersed solid or liquid form that are injurious to life. This has been particularly noticeable with those chemicals (e.g., DDT) that are spread for the purpose of exterminating pests but then accumulate to the extent that they can do damage to many other forms of life.

Air pollution involves the release into the atmosphere of gases, finely divided solids, or finely dispersed liquid aerosols at dangerous rates.

Air pollution results from a variety of causes, not all of which are within human control. Dust storms in desert areas and smoke from forest and grass fires contribute to pollution of the air. Forest fires that swept the state of Victoria, in Australia, in 1939 caused observable air pollution in Queensland, more than 2,000 miles (3,000 kilometres) away. Dust blown from the Sahara has been detected in West Indian islands. The discovery of pesticides in Antarctica, where they have never been used, suggests the extent to which pollutants can be carried by air from one place to another. Probably the most important natural source of air pollution is volcanic activity, which at times pours great amounts of ash and toxic fumes into the atmosphere.

Air pollution may affect humans directly, causing a smarting of the eyes or coughing. More indirectly, the effects of air pollution are experienced at considerable distances from the source, as, for example, the fallout of tetraethyl lead from urban automobile exhausts, which has been observed in the oceans and on the Greenland ice sheet. Still less directly experienced are the possible effects of air pollution on global climates.

It is the immediate effect of air pollution on urban atmospheres that is most noticeable and causes the strongest public reaction. The city of Los Angeles has been noted for both the extent of its air pollution and the actions undertaken for control. Los Angeles lies in a coastal plain, surrounded by mountains that restrict the inward sweep of air. Temperature inversions characterized by the establishment of a layer of warm air on top of a layer of cooler air prevent the air near the ground from rising and thus effectively trap pollutants that have accumulated in the lower layer of air. In the 1940s, the air in Los Angeles became noticeably polluted, interfering with visibility and causing human discomfort. Attempts to control pollution, initiated during the 1950s, resulted in the successful elimination of such sources of pollution as industrial effluents and the outdoor burning of trash. Nevertheless, pollution continued to increase as a result of the increased number of motor vehicles. Efforts to reduce pollution from automobile engines and to develop pollution-free engines may eventually eliminate the more serious air pollution problems. In the meantime, however, air pollution has driven many forms of agriculture from the Los Angeles basin, has had a serious effect upon the pine forests in nearby mountains, and has caused respiratory distress, particularly in children, elderly people, and those suffering from respiratory diseases.

Los Angeles is neither a unique nor the worst example of polluted air. Tokyo has such a serious air-pollution problem that oxygen is supplied to policemen who direct traffic at busy intersections. Milan, Ankara, Mexico City, and Buenos Aires face similar problems. Although New York City produces greater quantities of pollutants than Los Angeles, it has been spared from an air-pollution disaster only because of favourable climatic circumstances.

The task of cleaning up air pollution, though difficult, is not believed to be hopeless. Use of fuels that are low in pollutants, more complete burning of fossil fuels, the scrubbing of industrial smokestacks or precipitation of pollutants from them, often in combination with a recycling of the pollutants; and the shift to less polluting forms of power generation, such as solar energy in place of fossil fuels--all are methods that can be used for controlling pollution. The example of London, as well as of other cities, has shown that major improvements in air quality can be achieved in 10 years or less.

Water pollution involves the release into lakes, streams, rivers, and oceans of substances that accumulate to the extent that they interfere with the functioning of aquatic ecosystems. It may also include the release of energy in the form of radioactivity or heat, as in the case of thermal pollution.

Any body of water has the capacity to absorb, break down, or recycle introduced materials. Under normal circumstances, inorganic substances are widely dispersed and have little or no effect on life in water; organic materials are broken down by bacteria or other organisms. But, if the capacity of a body of water to dissolve, disperse, or recycle is exceeded, all additional substances or forms of energy become pollutants. Thus, thermal pollution, which is usually caused by the discharge of water that has been used as a coolant in electric power plants, raises the temperature of the water and can make it less suited to species.

Pollution may begin as water moves through the air, if the air is polluted.

Soil erosion adds silt as a pollutant. The use of chemical fertilizers and pesticides is an additional factor contributing to water pollution.

The runoff from septic tanks and the outflow of manures from livestock feedlots are sources of organic pollutants.

Industries located along waterways contribute a number of chemical pollutants, some of which are toxic if present in any concentration.

Finally, cities and towns contribute their loads of sewage and other urban wastes. The cost of cleaning water for community use may be high, and the process may be only partially effective.

The output of industries, agriculture, and urban communities generally exceeds the biologic capacities of aquatic systems, causing waters to become choked with an excess of organic substances and organisms to be poisoned by toxic materials. This encourages rapid growth, or blooms, of algae. When they die, the remains of the dead algae add further to the organic wastes already in the water; eventually, the water becomes deficient in oxygen. The result is a foul-smelling, waste-filled body of water, a situation that has already occurred in such places as Lake Erie and the Baltic Sea and is a growing problem in freshwater lakes of Europe and North America.

Noise pollution is characteristic of industrial societies. The intensity of sound is measured in decibels. A change from a level of 10 decibels to one of 20 decibels actually represents a 100-fold increase in the sound level. At a level of 80 decibels, sound is annoying; but steady exposure to noise in excess of 90 decibels--a level that is frequently exceeded by many common urban sounds, such as jackhammers, jet planes, and excessively loud music--can cause permanent loss of hearing. In addition to causing loss of hearing, there is some evidence that noise can produce other negative effects on human health and on work performance.

Many large cities have taken measures to decrease the level of urban noise; the problem has received much attention with the advent of supersonic jet airplanes. These aircraft, which travel at speeds faster than the speed of sound, create sound waves (sonic booms) equivalent to those of major explosions and capable of damaging structures.

Type of pollution	Definition	Causes	After-effects	Methods of fighting

3. Adapt the following text for 11^th-form pupils. Work in small groups to decide which lexical, grammatical and stylistical changes are necessary. Bear in mind that the resulting text should preserve the main ideas of the original, the language should adequately correspond to the level of pupils.Compare your adaptations with those of other groups, point out their good points and drawbacks.