Pollution
Scientific and technological progress has resulted in man’s intervention in nature. And man’s activity has created the threat to the environment. Many scientists consider that our world is going through a global ecological crisis which will lead to a gradual destruction of the human race. Factors ignored today may turn out to be very dangerous for the environment. All these problems are studied by ecology.
Modern ecology is based on Physics, Chemistry, Biology, Geography, Technology and other sciences.
At present we often hear about air pollution. Air pollution is a major problem of the environment. The air we breathe is becoming polluted by the products of man’s activities. At present the air contains 140 harmful substances: dust, smoke, soot, carbon dioxide, sulphur dioxide, nitric oxide, etc. Industry and transport are major sources of environmental pollution. The air of big cities is polluted greatly.
Plants and factories on our planet emit more than 250 million tons of toxic waste. The main air pollutants in cities are automobiles. Every car consumes many tons of air. It exhausts gases containing poisonous carbon dioxide. This gas prevents the emission of the Earth’s heat into space, which results in the so called “greenhouse effect” and global warming.
Water is considered to be the most essential material of civilization. Man cannot live and industry cannot operate without water. Rivers, seas and lakes are becoming highly polluted. This pollution comes from many sources: industrial wastes, thermal wastes from power stations, domestic wastes. Ships often pollute sea and river water with oil products. Pesticides from agricultural waste water and dangerous bacteria in municipal waste water discharges are also responsible for water pollution. Water pollution is harmful not only to people, but to fish, animals and birds as well.
Soil pollution is another current problem. The destruction of forests, rising salinity in the soil and erosion of farmlands affects soil fertility. Fruit and vegetables polluted with chemicals may affect people’s health.
Technological progress has resulted in increasing noise levels. High levels of noise at factories reduce work efficiency and may be dangerous for the workers’ health. Special laboratories have been set up to measure and control noise.
The end of the 20th century has brought man a number of natural and manmade disasters. Among them one can mention collisions and explosions of tankers in the sea, explosions and leakage of chemicals at industrial enterprises and accidents at nuclear power plants. Oil pollution of the sea has become a serious problem as well as the radioactive fallout. Chemical and radioactive pollution affects flora and fauna. People are developing dangerous illnesses.
Protection of natural environment is becoming increasingly important. A good deal of work in observing and estimating man’s impact on the biosphere is carried out by a number of international organizations. They develop programs of monitoring global changes in the earth atmosphere and in the state of the World Ocean. There are many control stations for checking the quality of air, land, fresh water and sea water. All large factories have purification systems.
Scientists all over the world develop ecologically pure and no-waste technologies. Powerful electric filters are used to purify air and water.
As to the automobiles, they will use environmentally friendly fuel-cells and electric cars have already appeared on the roads. All these measures will help to protect the environment.
There are over 150 “super cities” in the world with population from 1 to 15 million and more. Tokyo, New York, London, Mexico, Moscow are just a few of the “super cities”. Their number and size is growing rapidly and their population is increasingly affected by the polluted environment. Smog hanging over large cities is a major threat to human health. The environmental problems of “super cities” is a cause for concern of world scientists.