Air and Atmosphere - Air Pollution and its Control

Air pollution is the contamination of air by harmful substances like smoke, dust, and toxic gases which cause adverse effects on living organisms and the environment.

Major gaseous pollutants include Carbon monoxide ($CO$), Carbon dioxide ($CO_2$), Sulphur dioxide ($SO_2$), and Nitrogen oxides ($NO_x$).

Particulate pollutants consist of tiny solid or liquid particles suspended in the air, such as soot, fly ash, and dust (often measured as $PM_{2.5}$ or $PM_{10}$).

The Greenhouse Effect is the process where gases like $CO_2$ and Methane ($CH_4$) trap the sun's heat in the atmosphere, leading to Global Warming.

Acid Rain occurs when $SO_2$ and $NO_2$ react with water vapor ($H_2O$) in the clouds to form acids like Sulphuric acid ($H_2SO_4$) and Nitric acid ($HNO_3$).

Control measures include the use of cleaner fuels like $CNG$ (Compressed Natural Gas), installing tall chimneys with filters, and large-scale afforestation to balance $CO_2$ and $O_2$ levels.

The Ozone layer ($O_3$) in the upper atmosphere protects Earth from harmful UV radiation; it is depleted by Chlorofluorocarbons ($CFCs$).