0 a fog caused by light from the sun shining on chemicals in the air produced by traffic and industry --
They have an effect also on photochemical smog.
The same problem occurs with photochemical smog, except that in country areas the precursors would probably be widely dispersed before it developed.
It may be asked what exactly photochemical smog is.
Photochemical smog is one of the greatest environmental hazards faced by the capital city.
There is equal worry about photochemical smog, especially in cities, as a result of diesel emissions.
Finally, there are the unburnt hydrocarbons, which, in combination with nitrogen oxides, have been identified as a major cause of acid rain and photochemical smog.
Of greater importance is the reduction, which they cause, in visibility and the formation of photochemical smog.
Substitutes also include propane and butane, which may contribute to photochemical smog in a very small way.
