AIR POLLUTION

Natural Sources of Air Pollution:

  • Natural sources include volcanoes and sea spray contributing pollutants like sulfur dioxide (SO₂).

Criteria Pollutants:

  • Primary Pollutants: Directly released from sources such as sulfur dioxide (SO₂) and carbon monoxide (CO).

  • Secondary Pollutants: Formed through chemical reactions in the atmosphere (e.g., ozone).

  • Fugitive Emissions: Emissions that do not pass through a smokestack, such as dust.

Sulfur Dioxide (SO₂):

  • Major anthropogenic source includes fossil fuel combustion and smelting; also causes acid rain.

Nitrogen Oxides (NOx):

  • Produced during high-temperature combustion; contributes to smog and acid rain; significant human emissions.

Carbon Monoxide (CO):

  • Produced from incomplete combustion; prevalent in vehicle emissions; can interfere with oxygen transport in blood.

Ozone (O₃):

  • Beneficial in the stratosphere but harmful at ground level; a key component of photochemical smog.

Volatile Organic Compounds (VOCs):

  • Contribute to ozone formation in the presence of sunlight and nitrogen oxides.

Four-Cycle Internal Combustion Engine:

  • Typically generates emissions that include criteria pollutants, necessitating emissions control technology.

  • Catalytic Converter: A device used to reduce harmful emissions from internal combustion engines via chemical reactions.

Particulate Matter (PM10 and PM2.5):

  • Composed of various suspended particles; linked to respiratory problems; smaller particles (PM2.5) are especially harmful.

Industrial Smog:

  • Result from burning coal; characterized by the presence of sulfur dioxide and particulate matter.

Photochemical Smog:

  • Developed from reactions among nitrogen oxides and VOCs in sunlight; significant ozone formation.

Temperature Inversions:

  • A phenomenon where a layer of warm air traps pollutants close to the ground, leading to increased pollution levels.

Effects of Air Pollution:

  • Human Health: Air pollution is estimated to cause millions of premature deaths annually, linked particularly to PM2.5 exposure.

  • Environmental Impact: Acid rain damages forests, architecture, and reduces biodiversity.

Acid Rain:

  • Caused primarily by sulfur dioxide and nitrogen oxides; leads to soil and water body acidification.

Air Pollution Control Methods:

  • Techniques include emission reduction strategies, enhancing public transport, and implementing filtration processes.