Which of the following are likely to be present in photochemical smog?
1. Tropospheric ozone
2. Peroxyacetyl nitrates
3. Aldehydes
Select the correct option from the codes given below:

Answer: [D] 1, 2 & 3

Photochemical smog was first described in the 1950s. It is the chemical reaction of sunlight, nitrogen oxides and volatile organic compounds in the atmosphere, which leaves airborne particles and ground· level ozone. This noxious mixture of air pollutants can include the following:

  1. Aldehydes
  2. Nitrogen oxides, such as nitrogen dioxide
  3. Peroxyacyl nitrates
  4. Tropospheric ozone
  5. Volatile organic compounds

All of these harsh chemicals are usually highly reactive and oxidizing. Photochemical smog is therefore considered to be a problem of modern industrialization. It is present in all modern cities, but it is more common in cities with sunny. warm, dry climates and a large number of motor vehicles. Because it travels with the wind, it can affect sparsely populated areas as well.

This question is a part of GKToday's Integrated IAS General Studies Module