Brief History of Air Pollution

First human produced air pollution begins when humans first use fire.
Early accounts of air pollution characterize it a "smoke problems"
In 1273, King Edward I Longshanks of England banned the use of sea coal because of the smoke it produced
- the first "Clean Air Act"
By 1850 the Industrial Revolution had started in Europe and North America
London became known for its "pea-soup" fog - not a true fog, but a mixture of fog and smoke
In 1873 one such fog killed 700 people
In 1911 another killed 1150 people
- at this time a London physician, Harold Des Voeux, coined the term "smog" - smoke and fog
In 1952 nearly 4000 people died in one of the killer smogs.

Clean Air Acts

Great Britian passes its first Clean Air Act in _____.
United States passes its first Clean Air Act in _____.

Air Pollution

What is air pollution?

Types and Sources of Air Pollutants

Carbon Monoxide - CO
A colorless, odorless, poisonous gas
Sources:
Dangerous because red blood cells will more readily carry CO than oxygen, O₂

Sulfur Dixide - SO₂
Colorless gas, produced by combustion of sulfur bearing fossil fuels (coal, oil)
Primary sources:
Natural sources:

Nitrogen Oxides - NO_x
Forms during high temperature combustion of fuel
Nitrogen dioxide - NO₂
Nitric oxide - NO
Nitrogen dioxide reacts with water to form Nitric Acid - HNO₃
Nitric acid is a main component of acid rain
Primary sources:
Natural source:

Hydrocarbons
Compounds composed dominantly hydrogen, H and carbon, C
Methane, CH₄ is a hydrocarbon
Benzene, formaldehyde and CFCs
Sources:
Many hydrocarbons are carcinogenic

Particles
Any solid or liquid particle
Sources:

Temperature Inversions

Temperature inversions can trap smog and pollutants
Inversions occur when the temperature of an air mass increases with increasing altitude instead of decreasing as it normally does.
Convection occurs in an air mass because warm air rises.
In an inversion, the warm pollutants are unable to rise becuase itquickly reaches the temperature of the surrounding air.

Pollution Domes and Plumes

Pollution domes develop around sources of pollution (city or industrial complexes) when there is a stable air mass (no wind) - the pollutants remain over the source forming a dome of pollution.
Pollution plumes develop when wind carries the pollutants away from the source area.

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