Page 118 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

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Anthropogenic air pollution occurs mainly in urbanized regions, where it impacts human health. Photochemical smog produced by motor vehicle emissions is a major form of air pollution in cities. However, even in rural or isolated areas, air quality may be affected by pollution, such as
from coal-fired power plants. Industrial smog affects the immediate area, and can also be transported over long distances, especially when tall smokestacks emit pollutants high into the atmosphere. Adverse impacts, such as acid deposition, can thus occur far from the pollution source.
THE HUMAN-ATMOSPHERE-POLLUTION SYSTEM
Substances released by human activities interact with water and energy from solar radiation to produce different forms of air pollution.
INPUTS
Fossil fuel burning Transportation
Coal and oil plants Agriculture, fertilizers
Solar radiation Water
Air pollution from coal-burning industries, including electrical power generation, is known as industrial smog. Industrial pollution has high
OUTPUTS
Industrial smog Photochemical smog Acid deposition
ACTIONS
Chemical reactions
Sulfur oxides (SOx, SO2, SO3)
Colourless gas with irritating smell produced by combustion of sulfur-containing fuels
In the environment: Leads to acid deposition Health effects: Impairs breathing, causes human asthma, bronchitis, emphysema
This coal-fired power plant at
Barentsburg, Svalbard, lacks scrubbers to reduce stack emissions [Bobbe’ Christopherson.]
Nitrogen oxides NOx (NO, NO2)
Reddish-brown, choking gas given off by agricultural activities, fertilizers, and gasoline-powered vehicles
In the environment: Leads to acid deposition
3.1
INDUSTRIAL SMOG
concentrations of sulfur oxides, particulates, and carbon dioxide.
Health effects: Inflames respiratory system, destroys lung tissue
NO2 NO2
+ (nitrogen dioxide from combustion)
Particulate matter (PM)
Complex mixture of solids and aerosols, including dust, soot, salt, metals, and organic chemicals
In the environment: Dust, smoke, and haze affect visibility
Health effects: Causes bronchitis, impairs pulmonary function
SO2 +
O2
(oxygen)
+ H2O
(water)
H2SO4
(sulfuric acid)
H2O
(water)
CO Particulates 2
SO2
(sulfur dioxide)
Industrial smog
Acid deposition
Nitrogen from fertilizers
HNO3
(nitric acid)
Acid deposition
Analyze: Which pollutants could be reduced by switching to low-sulfur coal and installing scrubbers in smokestacks?
Visit the Study Area in MasteringGeographyTM to explore Geosystems in Action.
Visualize: Study a geosciences animation of air Assess: Demonstrate understanding of air pollution pollution. (if assigned by instructor).
geosystems in action 3AIR POLLUTION