4.11 Gas Pollution

4.11 Understand the biological consequences of pollution of air by sulphur dioxide and by carbon monoxide.


Sulphur Dioxide. (SO₂)
Comes from the combustion of fossil fuels, and combustion of petrols in vehicles.
In the atmosphere Sulphur dioxide combines with water vapour in clouds and forms Sulphuric Acid! this is what is known as acid rain,

SO₂ + H2O = H₂SO₄

acid rain has many effects on plants and animals:

1. Trees and plants are often damaged by the sulphuric acid
2. Sulphuric acid in the soil causes Calcium and Magnesium Ions to become leached* out of the soil, so the plant can't grow.
3. Acid rain in lakes reduces the pH to make them acidic, this causes a release of Aluminium Ions, which causes a thickening of the mucus that lines the gills, and reduces the ability to take Oxygen from water (the fish suffocates)

Leach - Make (a soluble chemical or mineral) drain away from soil, ash, or similar material by the action of percolating liquid, esp. rainwater

• - the nutrient is quickly leached away

Carbon Monoxide (CO)

Fossil fuels i.e. Coal/gas are burned with insufficient (not enough) Oxygen

Carbon monoxide combines with Haemoglobin inside red blood cells and forms Carbaminohaemoglobin which blocks the haemoglobin  from carrying Oxygen, therefore reducing Oxygen circulation and too much can be fatal.