1. POLLUTION

2. Air Pollution Naturally occurring – dust, pollen, volcanic eruptions
Human caused - Industrial burning, automobile exhaust
Two types of air pollution:
Primary: put directly into the atmosphere
(ex: volcano, vehicles & coal burning)
Secondary: forms in the atmosphere through chemical reactions
(ex: ozone, smog)

3. Industrial Air Pollution
Many industries and power plants burn fossil fuels to generate energy
(creates sulfur dioxide, carbon dioxide, soot & carbon monoxide in atmosphere)

4. Smog Depends on: - local climate - Fuels used - Population density - Open fires

5. Natural Dilution
Convection currents usually carry pollutants away from ground.
Air close to ground is usually warmer than air at higher altitudes
less pressure at high altitudes
less particles
therefore lower temperature

6. Natural Dilution
- When temperature inversions occur, pollution is trapped near the surface
- When air movement is low – disrupts convection
currents (at night, during a cold day, in a valley)
- Cool air settles close to ground, warm air forms a
blanket above it

7. Thermal Inversions

8. Indoor Air Pollution Sources: industrial chemicals, insulation,
carpets,
paint, radon,
carbon
monoxide,
asbestos
A “high risk health problem”

9. Indoor Air Pollution Can be reduced by:
Modifying building codes to prevent radon
Requiring exhaust hoods for applicances
Set emissions standards for building materials
Use office machinery in ventilated areas

10. Radon Gas - Produced by decay of uranium found in Earth’s crust.
- Seeps through small openings in buildings & sticks to dust particles

11. Radon Gas - Dust is inhaled by inhabitants & damages lung tissue
- Many houses with basements have radon detectors

12. Asbestos
- Silicate mineral - forms fibers that are heat-resistant, thin, strong, and flexible
- Used for insulation and fire resistance in building materials
- Found to be dangerous when inhaled and banned in 1970s

13. Asbestos
- Exposure to asbestos particles cause severe damage to lung tissue
- Causes difficulty breathing and possible heart failure

14. Acid Precipitation
- Rain, sleet, or snow containing a high concentration of acids due to air pollution
- Sulfur dioxide and nitrogen oxides combine with water vapor
to produce sulfuric acid
and nitric acid
- A regional problem

15. Acid Precipitation Flows into lakes, rivers, and streams.
Can kill/harm organisms

16. Acid Precipitation - Normal precipitation is slightly acidic
carbon dioxide forms carbonic acid
- Acid precipitation has pH of <5.6
- Typical rain in Eastern US is 4.6

17. Acid Precip. Damage
- Causes a drop in pH of soil and water (acidification) that results in loss of soil nutrients & plant root damage

18. Acid Precip. Damage - Can kill aquatic plants and animals.
- Causes aluminum to leach out of soil surrounding a lake.
accumulates in gills
fish suffocate

19. Acid Precip. Damage
- Acid shock - runoff of very acidic water into lakes and streams
- Decreases number of eggs produced at a time
many eggs do not hatch
birth defects common

20. Acid Precip. Damage - Bodily harm to humans - Economic impact
Toxic metals released soil can be absorbed by crops, water, and fish
- Economic impact
Decreases in numbers of fish
Damaged trees
- Aesthetic impact
harm to buildings

21. Acid Precip. Damage Statue on a German castle built in 1702
Photograph from Photograph from 1968

22. Chlorofluorocarbons Nontoxic
Used in air conditioners, aerosol spray cans, sterilants at hospitals and cleaners for computer chips.
Take years to reach stratosphere.
Greatest contributor = air conditioners

23. Review…
Carbon dioxide
Ozone
Layers of atmosphere

24. Who is affected? Infants Elderly
People with heart and respiratory disease
Pregnant women

25. Water Pollution Two main causes of water pollution:
1. Industrialization
2. Rapid human population growth

26. Water Pollution Comes from two types of sources: 1. Point sources
2. Nonpoint sources

27. Point-Source Pollution
Comes from a specific site

28. Nonpoint-Source Pollution
Comes from multiple sources

29. Wastewater - Contains wastes from homes or industry
- Wastewater treatment plants filter and treat water

30. Wastewater Treatment Process

31. Sewage Sludge - Byproduct of wastewater treatment
- Large volume of sludge is created each year
- If toxic
incinerated, and ash is buried in a secure landfill
- Low toxicity
used as fertilizer
combined with clay to make bricks

32. Eutrophication
Is accelerated when nutrients (P, N) enter water from fertilizer runoff, sewage, detergent.

33. Eutrophication - Decreases dissolved O2 in water
- Due to build up of organic matter
- Can convert body of water into swamp or marsh.

34. Thermal Pollution
- Temperature increase in a body of water caused by human activity
- Result of industrial use

35. Thermal Pollution - Decreased levels of oxygen
- Death of aquatic organisms (suffocation)
- Destruction of entire habitat

36. Groundwater Pollution
- Common pollutants:
Pesticides
Artificial fertilizers
Landfills
Industrial waste
Leaking septic/waste tanks

37. Cleaning Up Groundwater Pollution
- Big problem
- Length of time to recycle ground water
- Pollution can remain after water is recycled

38. Ocean Pollution - Dumping
Wastewater
Garbage
- Most (85%) ocean pollution come from coastal land
- Coral reefs exist near coasts and are deeply impacted

39. Oil Spills - Cause 5% of pollution in oceans
- Mostly from cities and towns

40. Water Pollution in Ecosystems
U.S. states limit amount of fish consumed from certain bodies of water

41. Water Pollution in Ecosystems
Biomagnification - accumulation of pollutants at successive levels of food chain.

42. Cleaning Up Water Pollution
- The Clean Water Act (1972) designed to restore and maintain clean water in US
- Goal: make surface water clean enough for fishing and swimming by 1983
Missed goal
Resulted in stricter water-quality standards nation-wide

43. Cleaning Up Water Pollution
- Marine, Protection, Research, and Sanctuaries Act (1972)
Prevent ocean dumping
- Oil Pollution Act (1990)
All oil tankers traveling in U.S. waters must have double hulls by 2015