Correct Answer - Option 2 : 1952
The correct answer is 1952.
The London smog was observed in the year 1952.
The London smog
- Great Smog of London, lethal smog that covered the city of London for five days (December 5–9) in 1952.
- It was caused by a combination of industrial pollution and high-pressure weather conditions.
- This combination of smoke and fog brought the city to a near standstill and resulted in thousands of deaths.
- Itis is also known as classical smog.
- Physician Harold Des Veaux coined the word smog in 1905 to describe natural fog contaminated by smoke: smoke + fog yielded smog.
Photochemical smog or Los angels smog
- This type of smog is prevalent in dry and sunny areas of the world.
- Automobiles emit smoke which contains hydrocarbons and nitrogen dioxide, these compounds under the action of sunlight become the major component of photochemical smog.
- This smog contains a high concentration of oxidizing agent hence it is also known as oxidizing smog.
- It was first observed in Los angels, USA, in 1943.