3. What Causes Air Pollution?
Primary and Secondary Pollutants
History of Air Pollution
Motor Vehicle Emissions
Industrial Air Pollution

4. What Causes Air Pollution?
Air pollution is the contamination of the atmosphere by wastes from sources such as
industrial burning
automobile exhausts.
Can be solid, liquid, or gas
Most air pollution is the results from human activities

5. What Causes Air Pollution?
Some air pollution is natural
Dust
Pollen
Spores
Sulfur dioxide from volcanic eruptions

6. Primary and Secondary Pollutants
Primary Pollutant:
One that is put into the air by human activity.
Ex: soot from smoke

7. Secondary Pollutant:
Results from a chemical reaction when a primary pollutant contacts either another one or a naturally occurring substance.
Ex:
ground level ozone =
car exhaust + UV rays from sun

9. Sources of Primary Air Pollutants
Primary Pollutant Sources:
Household products
Power plants
Motor vehicles
Primary pollutants:
Carbon monoxide
Nitrogen oxide
Sulfur dioxide
Volatile Organic Compounds (VOC’s)

10. Sources of Primary Air Pollutants
Particulate matter can also pollute the air
Divided into fine and coarse particles.
Fine particles enter the air from fuel burned by vehicles and coal-burning power plants.

11. Sources of course particles
cement plants
mining operations
incinerators
wood-burning fireplaces
fields and roads

14. Motor Vehicle Emissions
1/3 of air pollution
Controlling Vehicle Emissions:
EPA = Environmental Protection Agency
Clean Air Act in 1970
Catalytic converters: clean exhaust gases
Removed lead from gasoline
Zero emission vehicles

15. Catalytic Converter

16. Catalytic Converter

17. Industrial Air Pollution
VOC’s - Volatile Organic Compounds
form toxic fumes
Sources:
oil refineries
furniture refinishers
auto repair shops
dry cleaning

18. Industrial air pollution is regulated:
Clean Air Act
requires many industries to use scrubbers or other pollution-control devices
Scrubbers remove some of the more harmful substances that would otherwise pollute the air.

19. Smog is hanging air pollution that reduces visibility.

20. UV rays + exhaust + ozone
Smog
UV rays + exhaust + ozone

22. Temperature Inversions trap pollution near the earth’s surface.

26. 12.1 Review What is air pollution?
What is the cause of most air pollution?
What is the difference between a primary and secondary pollutant?
List two examples of primary pollutants.
What are the two examples of particulate air matter?
What are VOC’s? Give 3 sources of VOC’s.
What is smog?
Explain how a temperature inversion occurs.
List regulations of the Clean Air Act that have a direct impact on your air quality.

27. Activity
Section Review: page 308 #1-4
Write the questions & answers.