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What is air pollution?

‘I’ll go out for a breath of fresh air’ is an often-heard phrase. But how many of us realize that this has become irrelevant in today’s world, because the quality of air in our cities is anything but fresh.

The moment you step out of the house and are on the road you can actually see the air getting polluted; a cloud of smoke from the exhaust of a bus, car, or a scooter; smoke billowing from a factory chimney, flyash generated by thermal power plants, and speeding cars causing dust to rise from the roads. Natural phenomena such as the eruption of a volcano and even someone smoking a cigarette can also cause air pollution.

The gaseous composition of unpolluted air


The Gases Parts per million (vol)
Nitrogen 756,500
Oxygen 202,900
Water 31,200
Argon 9,000
Carbon Dioxide 305
Neon 17.4
Helium 5.0
Methane 0.97-1.16
Krypton 0.97
Nitrous oxide 0.49
Hydrogen 0.49
Xenon 0.08
Organic vapours ca.0.02

Air pollution is aggravated because of four developments: increasing traffic, growing cities, rapid economic development, and industrialization. The Industrial Revolution in Europe in the 19th century saw the beginning of air pollution as we know it today, which has gradually become a global problem.

Learn more about indoor air pollution, the air and its major pollutants, what you can do, and the problem of acid rain and smog.