Smog is caused when oxygen combines with nitrogen oxides from internal combustion engines or power plants in the presence of sunlight. Smog is fog or haze intensified by smoke or other atmospheric pollutants.

Photochemical smog, which is also known as “Los Angeles smog,” occurs most prominently in urban areas that have large numbers of automobiles. It requires neither smoke nor fog.

Sulfurous smog, which is also called “London smog,” results from a high concentration of sulfur oxides in the air and is caused by the use of sulfur-bearing fossil fuels, particularly coal. This type of smog is aggravated by dampness and…

Sulfurous smog, also known as “London smog,” is caused by a high concentration of sulphur oxides in the air, which is caused by the use of sulfur-containing fossil fuels, particularly coal. Photochemical smog, also known as “Los Angeles smog,” is most prevalent in urban areas with a high concentration of automobiles.