Page 112 - ICSE Chemistry 6

• Ac vi es like mining which release dust and chemicals in the atmosphere are responsible for air
pollu on.
• Use of radioac ve substances and explosives like atomic bombs, TNT, etc. during wars also causes
air pollu on.
• Volcanoes and forest fi res are examples of natural pollu on source.

Effects of Air Pollution

• Health problems: Air pollu on is known to cause irrita on in the eyes, nose and throat, and upper
respiratory infec ons such as bronchi s and pneumonia. Other problems include headache,
nausea and allergic reac ons. Long-term health eff ects can include chronic respiratory disease,
lung cancer, heart disease, and even damage to the brain, nerves, liver, or kidneys.
• Global warming: The atmosphere plays a very important role in regula ng the temperature on
the surface of the earth. Some of the gases present in the atmosphere trap heat energy from the
sun and thus help in reducing the temperature extremes between day and night. The gases that
trap heat energy of the sun are methane, carbon dioxide and water vapour. These gases are called
greenhouse gases. The trapping of the heat energy of the sun by greenhouse gases present in the
earth’s atmosphere is called greenhouse eff ect. Without the natural greenhouse eff ect, the sun’s
heat would escape into the space. This would make the earth a much colder place and then life
would not be possible on this planet. But due to human ac vi es, the concentra on of these gases
is increasing in the atmosphere. As a result, more heat is trapped which increases the average
temperature of the earth’s atmosphere. The sustained increase in the average temperature of the
earth’s atmosphere is known as global warming.
• Acid rain: Burning of fossil fuels results in the release of harmful gases like nitrogen oxides and
sulphur oxides. These gases combine with water droplets in the atmosphere, making them acidic
which fall on the ground in the form of acid rain. Acid rain results in reduc on in fer lity of soil,
destruc on of forests, aqua c plants and animals, damage to stone and marble buildings and
metals, etc.
• Eff ect on vegeta on: Air pollu on can damage crops and/or aff ect their growth.

• Smog forma on: When smoke, dust par cles, etc., mix with fog, it is known as smog and this
results in reduced visibility. This is responsible for road and rail accidents.
• Deple on of ozone layer: Ozone layer present in the earth’s stratosphere is responsible for
protec ng us from harmful ultraviolet (UV) rays. Air pollutants like chlorofl uorocarbons a ack the
ozone layer and are reducing its thickness. As this con nues, ultra-violet-rays reach the earth and
cause skin-related and eye-related problems.

Measures for Reducing Air Pollution
• Plan ng more trees is the best solu on to air pollu on. Plants maintain a balance between oxygen
and carbon dioxide present in the atmosphere and cause rainfall.

• Factories and industries should be situated far away from residen al areas. The smoke released by
them should be treated before releasing to the atmosphere.
• Public mode of transporta on should be used whenever possible. Car pooling is also a good way
of reducing vehicular exhaust.

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