1. Any harmful substances that can buildup in the air to unhealthy levels
Air Pollution
Any harmful substances that can buildup in the air to unhealthy levels

2. Sources of Pollution Primary Pollutant Secondary Pollutant
- Pollutant put directly into the air by human activity.
-Ex: soot from smoke.
Secondary Pollutant
- Primary pollutant reacts with other primary pollutants or with naturally occurring substances.
-Ex: ground level ozone (emissions react with oxygen)

3. Primary vs. Secondary Pollutants

4. Temperature Inversion
Temp. Inversion = when the air above is warmer than the air below it.
A temperature inversion can trap pollutants near the Earth’s surface b/c the warm air above doesn’t allow the cooler air to move upward.
Cities in a valley are more likely to experience temp. inversions (Ex: LA)

5. Air Pollution
What is the most common source of primary air pollutant in the US daily?
Which pollutant is released the most?

6. Types of Pollutants Carbon Monoxide - from car emissions
Sulfur Dioxide – from burning coal & oil

7. Carbon Monoxide - Motor Vehicle Emissions
Almost 1/3 of our air pollution comes from gasoline burned by vehicles.
Regulation - The Clean Air Act (1970) gives EPA the authority to regulate vehicle emissions in the US.
Eliminated lead in gasoline (unleaded)
Catalytic converters required that clean exhaust gases before exiting the tailpipe

8. Sulfur Dioxide - Industrial Air Pollution
Many industries, including power plants, burn fuel to produce energy.
Burning fossil fuels releases, sulfur dioxide, nitrogen oxides, & carbon dioxide into the air.
Regulation - Clean Air Act requires many industries to use scrubbers or other pollution-control devices.
Scrubbers remove some of the more harmful substances from emissions
Electrostatic precipitators remove dust particles from smokestacks.

9. Environmental Effect ~ Smog
Air pollution that hangs over urban areas and reduces visibility.
It results from chemical reactions that involve sunlight, air, auto exhaust, and ozone.
Caused mainly by auto and industrial exhaust

10. Effects of Smog Effects on Humans Effects on Plants
Respiratory problems like: - asthma emphysema chronic bronchitis
Eye irritations
Reduced resistance to colds and lung infections.
Effects on Plants
Inhibits plant growth
Damages crops

12. 1. Fossil fuels are burned,
Environmental Effect ~Acid Precipitation precipitation that contains high concentrations of acid.
1. Fossil fuels are burned,
releasing sulfur &
nitrogen oxides
2. These oxides combine
with water in the
atmosphere, forming
sulfuric acid & nitric acid
3. Acid precipitation falls
into lakes, rivers, &
streams; killing
organisms that live there

13. How Acidic Is It? pH is a measure of how acidic a substance is.
The lower the pH number is, the more acidic a substance is.
Pure water has a pH of 7.0 (neutral)
Normal precipitation is slightly acidic (pH 5.6)
Acid precipitation has a pH of less than 5.0
pH of eastern US & Canada ranges from

14. Effects of Acid Precipitation
Effects on Soil
Drop pH of soil
Nutrients decrease
Releases aluminum & other toxic metals
Effects on Plants
Soil changes cause root damage
Clogged openings on the surfaces of plants.

15. Effects of Acid Precipitation
Effects on Aquatic Ecosystems
Acid can kill fish & other aquatic animals. Aluminum builds up in the gills, suffocating them.
Effects on Humans
Toxic metals can find their way into crops, water, and fish
May increase respiratory problems
Dissolves calcium carbonate in concrete, marble, limestone, & monuments (ancient pyramids, Lincoln Memorial, etc.)

16. Problems with Acid Precipitation Control
Pollutants are often released in an area far away from the area where acid precipitation falls.
Ex: acid rain in SE Canada is a result of pollutants produced in NE United States.

17. Effects of Acid Precipitation – Ex: The Adirondack Mountains
A tree is weakened over time by acid rain, leaving it more susceptible to factors that would otherwise be harmless. Spruce and fir trees are so stressed by the acid pollution that they have succumbed to severe cold, drought, insect infestations or diseases. According to the U.S. Forest Service, death rates for many tree species have doubled or tripled in the last decade in the Adirondack Mountains.

18. Where is the acid rain?
Circle the areas with the most significant acid rain.
Draw an arrow to the sources of the sulfur dioxide.