Sir: The words pollute means to destroy the purity of thing by harmful materials. Air pollution means destroying the purity of air by smokes, harmful gases, chemical vapours and dust etc. Air pollution is the result of burning wood in the forest or domestic fuel more over the burning or use of fuel in the vehicles. Then the emission of carbon mono oxide, sulpher di-oxide nitrogen dioxide and other compounds also pollute the air. Another reason of air pollution is the emission of chlorofluoro carbon; setting up the new factories and the rapid increase in the use of carriers is increasing the emission to smoke in a large quantity. All this smoke is mixed up with the air which is damaging the ozone layer. Unfortunately Pakistan is one of those countries problem air pollution is increasing rapidly. Cutting the trees for different purposes is one of the major causes whereas trees absorb dioxide and minimize air pollution. Air pollution kills an estimated seven million people worldwide. It is my humbly request to the government that to take measure to reduce tree-cutting. MAINAZ ISHAQ Karki