The two types of smog are sulfurous and photochemical. Smog is defined as community-wide polluted air. The name was derived from the words smoke and fog.
Sulfurous smog is also known as "London smog." This type of smog is the result of a high volume of sulfur oxides found in the air. Sulfurous smog is the result of burning sulfur-bearing fossil fuels. An example of this type of fossil fuel is coal.
Photochemical smog is also called "Los Angeles smog." This type of smog is a result of the nitrogen oxides and hydrocarbon vapors exiting vehicles. Photochemical smog can reduce visibility and cause eye irritation and respiratory distress.