Major Primary Pollutants

Sulphur Oxides (SO_x)

• SO₂ is produced by volcanoes and in various industrial processes. Since coaland petroleum often contain sulphur compounds, their combustion generates sulphur dioxide.
• Further oxidation of SO₂, usually in the presence of a catalyst such as NO₂, forms H₂SO₄, and thus acid rain.
• This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.
• Effects: Respiratory problems, severe headache, reduced productivity of plants, yellowing and reduced storage time for paper, yellowing and damage to limestone and marble, damage to leather, increased rate of corrosion of iron, steel, zinc and aluminium.

Nitrogen Oxides ....