Summary Notes on Air Pollution

  • Atmosphere: Gaseous envelope surrounding Earth; composed of a mixture of gases essential for life.
  • Atmospheric Pollution: Presence of harmful substances in air that damage health, vegetation, and property; includes dust, smoke, and gases like CO, SO, and NO in undesirable concentrations.
  • Composition of Air:
    • Pure air: 20.946% Nitrogen, 78.084% Oxygen, 0.934% Argon; trace gases include Neon, Helium, etc.
    • Variable components: Water vapor (0-5%), CO2 (0.01-0.1%), Ozone (0-0.01%).
  • Sources of Pollution: Combustion of fossil fuels, waste treatment, natural sources like volcanoes; specific pollutants include SO2, CO2, NO.
  • Atmospheric Zones:
    • Troposphere: Contains 99% of atmospheric gases, temperature from 15°C to -56°C.
    • Stratosphere: Contains ozone layer; protects against UV radiation.
    • Mesosphere: Significant temperature drop.
    • Thermosphere: Very high temperatures with low density.
  • Meteorological Influences: Factors such as temperature, wind, humidity, and atmospheric pressure affect pollutant dispersion and deposition.
  • Historical Pollution Events:
    • Meuse Valley (1930): Toxicity due to pollutants in fog, resulted in deaths.
    • Donora (1948): Fog and pollution led to health issues for large population.
    • London (1952 & 1962): Serious smogs causing many deaths and health complications.
    • Bhopal (1984): Toxic gas leak leading to widespread illnesses and fatalities.
  • Classification of Air Pollutants:
    • By source, physical/chemical characteristics, and effects on health.
  • Health Effects of Air Pollution:
    • Affects animals and humans, causing respiratory issues, growth retardation, and ecosystem damage.
    • Specific pollutants like CO cause reduced oxygen levels, affecting health.
  • Control Measures: Improve sanitation, use of vacuums, proper ventilation, air filters, and laminar air flow systems to minimize pollutants risk in environments.