How cars cause pollution

The wheel of time turns, with technological advancements taking place exponentially every day; life and travel have become easy and comfortable with more and more vehicles on the road, gnawing away at our planet’s natural resources and polluting the very air that we breathe. Air pollution is associated with the complete life-cycle of vehicles – operation, refueling, manufacture and disposal, though the maximum extent of pollution occurs during operation. Cars consume gasoline, process it, convert the heat obtained by burning fuel into useful work which propels them and emit the by-products of combustion as smoke from their tailpipes. Iso-octane (C₈H₁₈), the dominant component of gasoline is obtained by fractional distillation of crude oil; this is the most common form of fuel used. The fuel undergoes combustion in the engine body, produces heat which runs the vehicle and the remnants of combustion are ejected out of the vehicle. 

Carbon dioxide, carbon monoxide, hydrocarbons, sulfur dioxide and oxides of nitrogen form the maximum percentage of the harmful fumes that are ejected from the vehicle. Particulate matter and water vapor also get ejected along with these gases, the former being the most serious threat to human health. Primary pollution is the initial stage of pollution when the gases are emitted in the atmosphere, whereas secondary pollution occurs due to the chemical reaction of the by-products with air or other pollutants. Hydrocarbons, carbon monoxide and sulfur dioxide react to produce more particulate matter thus contributing to secondary pollution. Ground-level smog, essentially ozone, is caused by the reaction of hydrocarbons and oxides of nitrogen in the presence of sunlight; this is a major cause of traffic jams and accidents since it hinders visibility. Though sulfur dioxide is generated only when the fuel used contains sulfur (diesel), it proves to be a major health hazard affecting the human respiratory system. 

There is another effect that the vehicular emissions produce, which is more pronounced than any others on a long-term – greenhouse effect. There are certain gases in the atmosphere like Carbon dioxide, whose balanced concentration helps maintain the Earth’s temperature; they act as greenhouse panes, letting in heat and insulating the system, thus keeping it warm. A slight increase in the concentration of greenhouse gases could mean a disastrous effect for the planet – uneven and unexpected weather changes, non-linear season patterns and unstable ecosystem.  Another form of pollution is noise pollution. Loud blaring horns, incessant honking and the drone of engines of vehicles, throughout the day, contribute to this form of pollution. This goes from disruption of the peace and harmony in a neighborhood to the extent of causing hearing disability in human beings, nervous disorders and mental tension.