Page 141 - Science Course 1 (Book 2)

Mo9-L6a: What is Air Pollution?

Natural sources of sulfur dioxide include volcanoes Key Concept
and marshes.
What is Air Pollution?
The most common sources of sulfur dioxide and
nitrogen oxides are automobile exhausts and factory How do humans impact air quality?
and power plant smoke.

Photochemical smog is air pollution that forms from
the interaction between chemicals in the air and
sunlight.

Smog forms when nitrogen dioxide, released in
gasoline engine exhaust, reacts with sunlight.

A series of chemical reactions produces ozone and
other compounds that form smog.

Ground-level ozone is the main component of smog.

SUMMARY
What is Air Pollution?

Air pollution comes from point sources, such
as factories, and nonpoint sources, such as
automobiles.

Photochemical smog contains ozone, which
can damage tissues in plants and animals.

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