Page 204 - Science Class 08
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Pollution of Air and Water
• Air pollu on — Sources of Air Pollu on — Harmful Effects of Air Pollu on
— Preven on and Control of A Pir ollu on
• Water pollu on — Sources of Water Pollu on — Effects of Water Pollu on
— Preven on and Control of Water Pollu on — Potable Water
An undesirable change in the physical, constant percentage of different gases in it, the
chemical or biological characteris cs of air, air is said to be polluted and this phenomenon
water or land is called pollu on. Pollu on can is referred to as atmospheric or air pollu on.
be natural or man-made. The agents or Sources of Air Pollu on
substances that cause such changes are called
There are several sources of air pollu on which
pollutants. Pollu on is perhaps the greatest
can be broadly categorised into:
threat of our modern and advanced world. The
harmful effects of pollu on have become a v Natural Sources
ma er of great concern which should be v Man-made Sources
tackled immediately and sincerely. In this Natural Sources : Whenever we talk about the
chapter, you will study about the causes, sources of air pollu on, we generally think
consequences and control of air and water about man-made sources. But natural sources
pollu on. are also responsible for air pollu on.
AIR POLLUTION v Ash and smoke released by volcanic
Air pollu on is the presence of foreign erup on cause air pollu on. Se ling
substances in the atmosphere that may harm volcanic ash can kill vegeta on of surroun-
living organisms directly or indirectly. So, when ding areas.
due to some natural processes or human v Powerful wind or storm puts dust par cles
ac vi es, the amount of solid wastes or into the air and pollute the air.
concentra on of gases other than oxygen
v Forest fires also release smoke and carbon
increases in the air which normally has
par cles causing air pollu on.
204 Science-8
