Air pollution occurs naturally. But most of the air pollution comes from the burning of fossil fuels. Fossil fuels include natural gas petroleum sui gas etc. Automobile exhaust frames also cause air pollution. This air pollution gives birth to acid rain .
Acid rain : Scientists have discovered and confirmed that sulphur dioxide and nitrogen oxide are the primary causes of acid rain.
Acid rain occurs when these gases react in the atmosphere with water , air and other substances to produce various acidic compounds.
Effects: Acid rain can damage trees kill huge areas of forest it washes out aluminium ions from the soil. These ions run into rivers lakes and ponds. Aluminium is very toxic to fish and other aquatic life. They can no longer survive in it and may be killed.
It also corrodes metals and marble surfaces. It is defined as
The rain having pH less than 5.6 is called acid rain