Polluting the Atmosphere

Burning fossil fuels in engines and power stations releases several pollutants into the atmosphere.Carbon monoxide comes from incomplete combustion. It is toxic because it binds to haemoglobin in the blood and stops it carrying oxygen.Nitrogen oxides (NO_x) form in engines, where the high temperature allows nitrogen and oxygen from the air to react: N₂ + O₂ → 2NO. NO_x causes acid rain and photochemical smog.Sulfur dioxide forms when sulfur impurities in the fuel burn. SO₂ dissolves in water in the atmosphere to form acid rain, which damages buildings, plants and aquatic life.Unburnt hydrocarbons and carbon particulates (soot) are also released. Unburnt hydrocarbons contribute to photochemical smog and particulates can cause breathing problems and lung disease.