Air pollution

Air pollution is a type of environmental pollution that affects the air and is usually caused by smoke or other harmful gases, mainly oxides of carbon, sulphur and nitrogen.

In other words, air pollution is the contamination of air due to the presence or introduction of a substance which has a poisonous effect.

Many of the world's large cities today have polluted air or low air and complain about its daily quality.^[1]

Even 2,000 years ago, the Romans were complaining about the polluted air in their cities. At that time, the air was thick with smoke from fires and the smell of sewers.^[1] Air pollution has been classified as a danger to human health and Earth's many ecosystems for a long time.

1. ↑ ^{1.0 1.1} Earth Science. Austin, Texas: Holt, Rinehart and Winston. 2001. ISBN 0-03-055667-8.