Particulate Pollutants


 
 
Concept Explanation
 

Particulate Pollutants

A pollutant is a substance or energy introduced into the environment that has  undesired effects, or adversely affects the usefulness of a resource.There are basically two types of pollutants :-

Primary pollutants :-

Pollutants that are formed and emitted directly from particular sources.The source can be either a natural process such as sandstorms and volcanic eruptions or anthropogenic such as industrial and vehicle emissions. Examples are carbon monoxide, nitrogen oxide and sulfur oxide.

Secondary pollutants :-

Secondary pollutants are defined as pollutants in our environment that are formed when other primary pollutants interact with the atmosphere. Unlike primary pollutants, which are air, water or soil pollutants that are emitted directly from a particular source, secondary pollutants pollute our environment indirectly and are not emitted from source, but are activated or synthesized by other pollutants as they are emitted. Secondary pollutants include ground-level ozone, acid rain and nutrient enrichment compounds

Particulate Pollutants

These are the pollutants that are in the form of minute particles. It may be solid (like dust, sand, tobacco and smoke) or liquid (as water droplets, mist, fog). The particulate matter remains suspended in the atmosphere and are therefore, termed as Suspended Particulate Matter (SPM). The suspended particulate matter in air is also known as Aerosol.

These tiny particles are also produced by automobiles. These are fine particles of carbon. Very fine SPM enter our lungs with the air we breathe in. They are the major cause of lung diseases. SPM settles on plants and interferes with photosynthesis. SPM reduce visibility, especially during winters. The presence of SPM is also visible in such areas where factories are located.

Sources of SPM includes construction sites, unpaved roads, smokestacks or fires. Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles.

Particulate pollution comes in all shapes and sizes, but is generally grouped into three categories : coarse, fine and ultra fine. Particles that are 10 micrometers(mu m) in diameter or smaller pose the greatest problems.These smaller particles generally pass through the nose and throat and enter the lungs. PM 2.5 and PM 10 are minute particles present in the air and exposure to it is very harmful for health. When the level of these particles increases and penetrate deeply in to the lungs and causes different health issues.

Sample Questions
(More Questions for each concept available in Login)
Question : 1

What is the size range of particulate matter which causes the most harm ?

Right Option : C
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Question : 2

Ozone layer in upper atmosphere ( stratosphere ) is destroyed by ______________________

Right Option : C
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Explanation
Question : 3

Pollutants that are formed and emitted directly from particular sources is called __________________ .

Right Option : B
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Explanation
 
 


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