Secondary Pollutants

Secondary pollutants form in the atmosphere when primary pollutants from sources like vehicles or power plants react with other atmospheric compounds.

Secondary Pollutants
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Secondary Pollutants Latest News

Secondary pollutants, particularly ammonium sulphate, are responsible for nearly one-third of India’s fine particulate matter (PM2.5) pollution, said a study from the Centre for Research on Energy and Clean Air (CREA).

About Secondary Pollutants

  • Secondary pollutants are pollutants which form in the atmosphere. 
  • These pollutants are not emitted directly from a source (like vehicles or power plants).
    • Pollutants that are emitted into the environment from a source are called primary pollutants.
  • Secondary pollutants form as a result of the pollutants emitted from these sources reacting with molecules in the atmosphere to form a new pollutant. 
  • Examples of secondary pollutants are ozone and secondary organic aerosol (haze).
  • Secondary pollutants are harder to control because they have different ways of synthesizing, and the formation is not well understood. 
  • They form naturally in the environment and cause problems like photochemical smog.
    • The phenomenon of photochemical smog is a result of the interactions of primary pollutants with other molecules in the air, such as molecular oxygen, water, and hydrocarbons.
    • These combine to form yellow clouds that are harmful to humans.

Source: TH

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Secondary Pollutants FAQs

Q1. What distinguishes secondary pollutants from primary pollutants?+

Q2. Why are secondary pollutants harder to control compared to primary pollutants?+

Q3. What is an example of a secondary pollutant?+

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