Environmental Pollution


3.2  Environmental Pollution
1. Types and sources of environmental pollution
Type of environmental pollution Sources of environmental pollution
Air pollution
  • Natural air pollution
    • volcanic eruptions
    • forest fires
    • dust storms 
    • decaying organic waste
  • Man-made air pollution
    • exhaust gases from motorised equipment or vehicles
    • blast furnaces
    • thermal power stations
    • industries and garbage disposal sites
Water pollution
  • Waste 
    • wastewater
    • domestic waste such as detergents and sewage 
    • solid waste such as rubbish
    • industrial waste such as grease
  • Chemical substances used in agriculture such as chemical fertilisers and pesticides 
  • Oil spills
Land pollution
  • Excessive use of fertilisers and pesticides
  • Inappropriate management of solid waste
  • Acid rain
  • Nuclear waste 
  • Electronic waste
Thermal pollution
  • Deforestation 
  • Industrial activities
  • Fuel combustion in vehicles or machines

2. Level of water pollution from domestic waste

  • Air pollutant index (API): air pollution parameter which is measured to determine air pollution level 
  • Biochemical Oxygen Demand (BOD):
    • the water pollution parameter which is measured to determine water pollution level
    • the amount of dissolved oxygen needed by microorganisms
    • the higher the BOD of a water sample, the more microorganisms can be found in it