Question

Photochemical smog found mainly in 

• A. Industrial area
• B. Marshy place
• C. Hilly area of Himachal
• D. Cold humid climate

Answer 1

The Correct Option is A

• Photochemical smog is a type of air pollution that forms when sunlight reacts with pollutants such as nitrogen oxides (NO_x) and volatile organic compounds (VOCs), which are primarily emitted by vehicles, factories, and industrial processes.
• It is characterized by the presence of secondary pollutants like ozone (O₃), peroxyacetyl nitrate (PAN), and aldehydes, which are harmful to both human health and the environment.
• Industrial areas often have higher emissions of NO_x and VOCs due to:
  • Combustion of fossil fuels in power plants and factories.
  • Heavy vehicular traffic.
  • Emissions from chemical and manufacturing processes. 

Why Industrial Areas Are Prone:

Industrial areas have the necessary conditions for photochemical smog formation, including:

• High levels of precursor pollutants (NO_x and VOCs).
• Strong sunlight, which triggers photochemical reactions.
• Temperature inversions, which trap pollutants close to the ground.

Conclusion:

Photochemical smog is primarily found in industrial areas due to the significant emissions of pollutants from vehicles and factories.

Answer 2

Photochemical smog is most likely to be found in sunny desert areas. This is because photochemical smog is formed due to the reaction of nitrogen oxides and volatile organic compounds in the presence of sunlight. Sunny and warm climates with high levels of automobile traffic and industrial activity tend to have higher levels of nitrogen oxides and volatile organic compounds, which can contribute to the formation of photochemical smog. Desert areas with high levels of traffic and industrial activity are particularly susceptible to photochemical smog because they receive high levels of sunlight and have stagnant air conditions that trap pollutants.