Page 4 - 2. Lesson notes- Air, Rain and Air pollution

AIR POLLUTION:

What is Air Pollution?

Air pollution refers to any physical, chemical or biological change in the air. It is the
contamination of air by harmful gases, dust and smoke which affects the plants, animals, and

humans drastically.

Types of Air Pollutants

There are two types of air pollutants:

➢ Primary Pollutants

The pollutants that directly cause air pollution are known as primary pollutants.

Sulphur- dioxide emitted from factories is a primary pollutant.

➢ Secondary Pollutants

The pollutants formed by the intermingling and reaction of primary pollutants are known as
secondary pollutants. Smog, formed by the intermingling of smoke and fog, is a secondary

pollutant.

Causes of Air Pollution

1.Burning of Fossil Fuels

The combustion of fossil fuels emits a large amount of sulphur dioxide. Carbon monoxide

released by incomplete combustion of fossil fuels also results in air pollution.

2. Automobiles

The gases emitted from vehicles such as jeeps, trucks, cars, buses, etc. pollute the

environment. These are the major sources of greenhouse gases and also result in diseases
among individuals.

3. Agricultural Activities

Ammonia is one of the most hazardous gases emitted during agricultural activities. The

insecticides, pesticides and fertilizers emit harmful chemicals in the atmosphere and
contaminate it.

3. Factories and Industries