Learning Objectives

To make the students aware of history of air pollution; definition of air pollution and various types of sources and classification of air pollutants.

Lecture 1 Lecture 2 Lecture 3

Air Pollution
Transfer of harmful and/or of Natural/Synthetic materials into the atmosphere as a direct/indirect consequences of human activity (OECD).

Air Pollution Definition Based on System Approach


Types of Air Pollution

  • Personal air exposure
    -It refers to exposure to dust, fumes and gases to which an individual exposes himself when he indulge himself in smoking

  • Occupational air exposure
    -It represents the type of exposure of individuals to potentially harmful concentration of aerosols, vapors, and gases in their working environment.

  • Community air exposure
    -This is most serious, complex, consists of varieties of assortment of pollution sources, meteorological factors, and wide variety of adverse social, economical, and health effects.

The Earth’s Great Spheres


Lithosphere- The lithosphere contains all of the cold, hard solid land of the planet's crust (surface), the semi-solid land underneath the crust, and the liquid land near the center of the planet
Hydrosphere- The hydrosphere contains all the solid, liquid, and gaseous water of the plane
Biosphere- The biosphere contains all the planet's living things. This sphere includes all of the microorganisms, plants, and animals of Ear
Atmosphere- The atmosphere contains all the air in Earth's system


  • It is a mixture of gases that forms a layer of about 250 miles thick around the earth.
    - Bottom 10-12 miles (Troposphere) is most important part in terms of
    • Weather
    • Other aspects of Biogeochemical cycle
  • - The lowest 600 meters of Troposphere: Air Quality Studies
  • Composition of Air - 78% nitrogen, 21% oxygen, 1% carbon dioxide, water, other gases
  • Divided into four zones:
    - Troposphere
    - Stratosphere
    - Mesosphere
    - Thermosphere

Source of Air Pollution
  • Natural Sources –Volcano, forest fire, dust storms, oceans, plants and trees
  • Anthropogenic Sources - created by human beings
    -Stationary sources
    • Point sources (Industrial processing, power plants, fuels combustion etc.)
    • Area sources (Residential heating coal gas oil, on site incineration, open burning etc.)
    - Mobile sources
    • Line sources (Highway vehicles, railroad locomotives, channel vessels etc.)


Air Pollutants

Any substance occurring in the atmosphere that may have adverse effects on humans, animals, plant life, and/or inanimate materials. Air pollutants have known or suspected harmful effects on human health and tironment.

Criteria Air Pollutants
  • Based on health effects with measured air quality levels that violate the National Ambient Air Quality Standards (NAAQS)
  • (NAAQS)

Hazardous Air Pollutants

  • Predecessor: National Emission Standards for Hazardous Air Pollutants (NESHAPs)
  • Clean Air Act Amendments of 1990 directed EPA to establish emission controls for 189 chemicals listed in the Act.
    -NOT based on health criteria
    -Based on Maximum Achievable Control Technology (MACT)

Non-Criteria Pollutants

  • In essence, all pollutants not included in the NAAQS and HAP lists
  • Examples: