Page 31 - ICSE Science 3 : E-book

Causes of air pollution

Air pollution is caused due to the smoke and harmful gases that are released from
various sources. For example, smoke released from vehicles, factories, forest fi res

and bursting of crackers pollute the air. Burning of wood, coal, leaves, polythene
and garbage also adds smoke to our environment. Discharge of harmful gases
from the power plants, refrigerators and air conditioners are the other causes of

air pollution.

Eff ects of air pollution

• It causes respiratory (lung) diseases such as asthma, chest pain and lung
cancer, and heart diseases.
• It can cause other health problems like coughing, dizziness, headaches, skin

problems, and irritation in eyes, nose and throat.

• It can even have harmful eff ect on crops, Did You Know!
buildings and monuments. Ozone layer is a thick layer that
surrounds the earth’s surface. It
• It causes changes in the climatic conditions.
protects the life on earth from
• Presence of harmful substances in the air can harmful radiations that comes

also cause holes in the ozone layer. from the sun.

TIME TO REVISE

Answer the following in one word.
1. Addition of harmful substances to the air as a result of human

activities ___________
2. Process that results in the better supply of oxygen into the lungs ___________

3. Process of taking in oxygen and giving out carbon dioxide ___________
4. Spongy bag-like structures of the respiratory system ___________

5. An organ that is also called throat or trachea ___________

Ways to reduce air pollution
• Plant more trees to increase the level of oxygen in the air.

• Use CNG fuel for vehicles and get their regular pollution checks done.

• Use public transport instead of your own vehicles whenever possible.

• Switch off the lights and fans when not in use.

17