Page 196 - Chemistry ICSE Class IX

8 Atmospheric Pollution

Environment and Environmental Pollution
CONTENTS
Environmental chemistry is the branch of chemistry that deals with the
ͻ ŶǀŝƌŽŶŵĞŶƚ ĂŶĚ ĞŶǀŝƌŽŶŵĞŶƚĂů study of various chemical processes that take place in the various segments
ƉŽůůƵƟŽŶ of the environment. It is a multidisciplinary science that involves chemistry,
ͻ dŚĞ ĂƚŵŽƐƉŚĞƌĞ physics, life sciences, medical science, public health, chemical engineering
ͻ tŚĂƚ ĂƌĞ ƚŚĞ ŚĂƌŵĨƵů ĞīĞĐƚƐ ŽĨ
ĐĂƌďŽŶ ŵŽŶŽdžŝĚĞ and waste management.
ͻ Smog What is meant by environment
ͻ ĐŝĚ ƌĂŝŶ
ͻ 'ůŽďĂů ǁĂƌŵŝŶŐ The physical and biological world around us is called environment. It has
ͻ dŚĞ ŐƌĞĞŶŚŽƵƐĞ ĞīĞĐƚ three components. These are:
ͻ KnjŽŶĞ ĚĞƉůĞƟŽŶ ƒ Physical surroundings, such as soil, water bodies, and atmosphere
ƒ Living organisms, such as plants, animals, and human beings
ƒ Meteorological factors, such as sunlight, temperature, and rainfall.

What is meant by environmental pollution
Any substance that causes pollution is called a pollutant. A substance
becomes pollutant when its concentration increases beyond a certain
permissible limit in the environment.
The contamination of the environment with harmful toxic, poisonous
substances due to certain natural phenomenon and human activities is
called environmental pollution.
The mechanism from the generation of any pollutant to the damage
caused by it is called the pollution process.
What are the various types of environmental pollution

Environmental pollution can be categorised in the following types:
ƒ Atmospheric pollution (or Air pollution) ƒ Water pollution
ƒ Soil pollution (or land pollution) ƒ Thermal pollution
ƒ Noise pollution ƒ Radiation pollution
In this chapter, we will describe the atmospheric pollution (or air
pollution).
What are the various types of pollutants

Various types of pollutant are:
ƒ Biodegradable pollutants. The pollutants which can be degraded
into simpler, nontoxic substances by the action of microorganisms
are called biodegradable pollutants.
Examples: Agricultural waste, Animal dung, Cotton cloth/ bre,
Human excreta, Organic component of sewage, Dead and decaying
animals etc.
ƒ Primary pollutants. The pollutants which enter the environment
directly from various sources are called primary pollutants.