1. Chapter 12
Air

2. 12-1 Causes of Air Pollution
Clean air = mostly nitrogen and oxygen gases
Air pollution is harmful substances in the form of liquids, solids or gases
Primary pollutants are put into the air by human activity
Secondary pollutants are formed when primary pollutants react with normal air components such as water vapor

4. Sources Carbon Monoxide: vehicles
Nitrogen Oxide: vehicles, power plants
Sulfur Dioxide: burning of coal/oil
Volatile organic compounds: vehicles, gas station spillage, household products
Particulates:
Fine: vehicles, power plants
Coarse: cement, mining, wood-burning, fields, roads

5. Although air pollution is worse today because of modern industry, it has been a problem for thousands of years

6. Clean Air Act of 1970
EPA has the authority to regulate vehicle emissions in the US
90% of lead pollution reduced when gasoline became unleaded
Catalytic converters filter pollutants
Industries must use air scrubbers (pg. 307)
Electrostatic precipitators clean smoke stacks

7. Motor Vehicle Emissions
1/3 of all air pollution is from vehicles
1990 California Air Resources Board established the zero emission vehicle (ZEV) program
By % of vehicles in California must be ZEVs
Electric, advanced battery, hydrogen fuel vehicles will qualify
Hybrids are partial ZEVs

8. Industrial Air Pollution
Power plants burn fossil fuels releasing:
2/3 of all sulfur dioxide
1/3 of all nitrogen oxides
VOCs
Other industries producing VOCs:
Dry cleaning
Oil refineries
Chemical manufacturing plants
Auto repair shops
Furniture refinishers

9. Smog
Pollution hanging over urban areas that mixes with sunlight and ozone

10. Temperature Inversions
Air above is cooler than air below which traps pollutants that are normally circulated out

11. 12-2 Air, Noise & Light Pollution

12. Short Term Effects Headache Nausea Eye, nose, throat irritation
Coughing
Upper respiratory infections
Pneumonia
Aggravates Asthma/Emphysema

13. Long Term Effects
Emphysema
Lung cancer
Heart disease

14. Indoor Air Pollution
Sick-building syndrome – Buildings with very poor air quality due to:
Plastics
Paints
New carpeting/furniture
Building materials
Common in tightly sealed buildings

15. Radon Colorless, tasteless, odorless Produced by the decay of uranium
Seeps through the foundations of homes
2nd leading cause of lung cancer in the US

16. Asbestos Used as insulator/fire retardant Banned in the early 70’s
Asbestos fibers can cut and scar the lungs
Causes serious illness and death

17. Noise Pollution May cause health problems too!
Hearing loss
High blood pressure
Stress
Decibels (dB) – measures sound intensity
See chart on page 312

18. Light Pollution Doesn’t pose health threat
Negatively affects the environment
Diminishes view of night sky
Energy waste

19. 12-3 Acid Precipitation

20. Causes
Sulfur oxides and nitrogen oxides are released from the burning of fossil fuels
These combine with water in the atmosphere which falls as acid rain
Adversely affects ecosystems

21. pH Scale that determines how acidic or basic a substance is
See page 314
7 is neutral
Lower numbers (below 7) are higher acidity
Higher numbers (above 7) are higher basicity

22. Affects on Soil/Plants
Increase soil acidity
Decreases nutrients
Increases toxic metals that are absorbed into roots
Clogs surface openings on plants

23. Affects on Aquatic Ecosystems
Acid shock may be fatal for fish and other organisms
Affects reproduction
Acidified lakes are treated with limestone to raise the pH

24. Affects on Humans Toxic metals from soil into food chain
Increase in respiratory problems
Dissolves building materials

25. International
Pollutants released in one area fall as acid precipitation in another area
International agreements are needed to control the problem