Air pollution is a worldwide concern today. In India too, this problem has been dominating the public mind. Indisputably, the quality of air we breath has deteriorated with toxic substances from many sources - industry, automobiles and refrigeration/air-conditioning equipment, to name a few. Together, this pollutants lead to environmental disasters like acid rain, photochemical smog, ozone layer depletion and other ecological imbalences. Their effect on human victims - from headaches, dizziness and eye irritation to brain damage, respiratory problems, cancer, kidney damage and cardiovascular deaths.
Inside the Combustion Chamber
The power that propels automobiles comes from combustion in the combustion chamber. That is where fuel (hydrocarbons) meets air. Ideally, oxygen in the air converts all the hydrogen in the fuel to water and all the carbon in the fuel to carbon dioxide. But in reality, combustion also produces unburned hydrocarbons, oxides of nitrogen, carbon monoxide and water.
Indian Emmision regulations
In india, the first piece of legislation was the Air Pollution Act of 1991. The permissible levels of gaseous automobile exhaust emissions were tightened in 1996. The pattern followed by India for the emission norms is based on European practice. For commercial Vehicles with diesel engines,the norms are based on European legislation (EEC). European regulation generally tend to follow the American regulations. However, both in Europe and America, there are some countries/states where the regulations are tigher than elsewhere depending upon the needs and as perceived by that country/state. The government of India has set April 1, 2000 as the date to implement the next set of emission standards that will apply for all deisel vehicles manufactured on or after that date. Clearly, vehicles manufactured prior to that date need not conform to the new norms. The norms for diesel vehicles largely tally with Euro 1 norms.