How pollution is caused from
vehicles :
In an engine, fuel is burnt with air. Fuel (petrol or diesel) consists of Hydrocarbons.
Air mainly consists of Oxygen only Carbon Dioxide and water vapor coming out of engines
cannot burn the fuel completely. Because of such incomplete combustion, Carbon Monoxide is
produced. Part of the fuel which has not been burnt comes out as unburnt Hydrocarbons. The
high temperature inside the engine (about 2,000 centigrade) causes the Oxygen and Nitrogen
in the air to combine and form various Oxides of Nitrogen. Thus, CO, unburnt HC and
Nox come out of vehicular exhaust. All these are harmful to human beings.
The effect of Carbon Monoxide on health :
Carbon Monoxide combines with Haemoglobin in the blood to form Carboxy Haemoglobin. The
normal function of Haemoglobin is to pick up Oxygen from air when we breathe and supply
Oxygen to all the body tissues in a human being. Unfortunately the affinity of Haemoglobin
for CO is 200 times more than its affinity for Oxygen. Hence when CO is present in the
air, Haemoglobin molecules pickup CO instead of picking up Oxygen. So the body tissues get
deprived of Oxygen. Because of this a series of respiratory diseases are caused.
Emission
Standards |
Limit |
| Four wheeler-Petrol |
3 % by
Volume |
Two
& Three wheeler-Petrol |
4.5% by
Volume |
Diesel Vehicle
a) Full Load
b) Free Acceleration |
75 Hartridge
65 Hartridge |
|
