Primary air pollutants include carbon monoxide from the burning of
organic materials, hydrocarbons from automobile exhaust, particulates from
industrial plants, sulfur dioxide from electric generation facilities using
high sulfur fuels, and oxides of nitrogen from internal combustion engine
exhaust.
The 6 criteria air pollutants and their primary sources are:
carbon monoxide—burning of fossil fuels (Automobiles are the primary source.);
nitrogen dioxide—secondary air pollutant formed from nitrogen monoxide released
from automobiles;
sulfur dioxide—burning of sulfur-containing fossil fuels, primarily coal in
power plants;
volatile organic compounds (hydrocarbons)—evaporation or incomplete burning
of hydrocarbons, primarily automobiles;
ozone—a secondary air pollutant formed by the interaction of volatile organic
carbons and nitrogen oxides released from cars;
lead—primary sources today are industrial processes (Formerly, leaded gasoline
was a primary source.).
Secondary air pollutants are compounds that result from the interaction
of various primary air pollutants. Photochemical smog forms when hydrocarbons
and oxides of nitrogen are trapped by thermal inversion and react with ultraviolet
light.
Health effects of air pollution include bronchial inflammation, allergic
reactions, irritation of the mucous membranes of the eyes and nose, and
asthmatic problems.
Increased pollution in industrialized urban areas is due to the large
number of industrial plants, the large concentration of automobile traffic
in these areas, and temperature inversions that cause large amounts of pollution
to accumulate.
Photochemical smog is a secondary pollutant caused by the interaction
of nitrogen oxide, nitrogen dioxide, and hydrocarbons with ultraviolet light.
It is caused by exhaust from internal combustion engines and is intensified
in valleys that produce temperature inversions.
Air pollution can be controlled by building taller smokestacks, installing
emission control devises in automobiles, and legislating to control or eliminate
open burning.
Acid rain is the deposition of wet acidic solutions or dry acidic
particles from air. Detrimental consequences include abnormal bone development
in fish, damage to limestone structures and monuments, damage to metal surfaces,
and death of many kinds of trees and other vegetation.
Although carbon dioxide is a naturally occurring substance, much larger
quantities are put into the atmosphere as a waste product of energy production.
This increased amount allows light and heat to pass through the atmosphere
to the earth’s surface but hinders its reradiation back into space.
If the ozone layer was destroyed, more ultraviolet light would reach
the earth’s surface, causing increased skin cancers and cataracts in humans
and increased mutations in all organisms.
Since most air pollution results from the burning of fossil fuels,
energy conservation would decrease the amount of fossil fuels burned and
reduce the amounts of carbon monoxide, HC, sulfur dioxide, and other pollutants
in the atmosphere.
