How can Sulphur Dioxide and Nitrogen Oxides be Released into the Atmosphere?

-This is can be as a result of Burning Fossil Fuels -Sulphur comes from the Impurities in the Fossil Fuels -Nitrogen Oxides comes from the Reaction of Nitrogen and Oxygen in the Air, in which the Heat from the Combusting of Fossil Fuels also Helps. [In the Engines]