Sir: Our earth is a paradise if we live on it in a sensible way, otherwise it is another name for hell. Unfortunately, at present, man is misusing the resources of the earth, which can spell doom for his own existence. Air, soil, water and space, all are becoming polluted. Air pollution is taking place because of mindless felling of trees and poisonous emissions from factories and automobiles. Excessive use of insecticides and pesticides is causing soil pollution. Poisonous elements are finding their way into our food, grains and milk. Water channels like rivers and canals are becoming polluted due to the release of highly deleterious effluents into them by industrial units. Even sea water is becoming polluted. Tons of debris from spaceships and satellites is polluting space. Experimental nuclear explosions and leakages from nuclear plants also cause atmospheric pollution. Quite another type of pollution is noise pollution. It is caused by loudspeakers, factory buzzers, vehicular horns, high pitch of TV sets and radios, and noises in streets and markets. Noise pollution can cause great injury to our delicate nerves. In fact, all pollution is harmful to man in more than one way. It is high time that man gives attention to the hazard of pollution of all kinds. Otherwise, there may be not only widespread epidemics, but even his existence on this planet may be in danger. S HUSSAIN HYDER ZAIDI Karachi