Acid rain is a broad term referring to a mixture of wet and dry deposition (deposited material) from the atmospheric containing higher than normal amounts of nitric and sulfuric acids. The precursors, or chemical forerunners, sulphuric acids. The precursors, or chemical foerunners, of acid rain formation result from both natural sources, such as volcanoes and decaying vegetation, and man-made sources, primarily emissions of sulfur dioxide (So2) and nitrogen dioxides (No2) resulting from fossil fuel combustion, Acid rain occurs when these gases react in the atmosphere with water, oxygen, and other chemicals to forms various acidic compounds. The result is a mid solution of sulphuric acid and nitric acid. When sulphur dioxide and nitrogen oxides are released from power plants and other sources, prevailing winds blow power these compounds across state and national borders, sometimes over hundreds of miles. Bhopal Gas Tragedy, where methyl-iso-cynatate was released in environment, which is a known Toxicant, is also an incident of toxication of environment. Innocuous looking presence of plastic has also introduced toxicity in our food chain. Recent incident of fatality among children due to introduction of toxicity in their system through the use of plastic toys was also an example of toxication. So we have to control /Measure of Air pollution that is * Suitable fuel selection * Modification in industrial processes * Correct selection of manufacturing site * More efficient engines * Euro-Emission Norms Euro 1 and Euro 2 names are given to emission norms for new petrol and diesel driven vehicles. Extents of emission of CO, HC, NO2 and particulate matter have been specified in terms of gm/km.