1. Pollution and Degradation
…of the Lithosphere, Hydrosphere and Atmosphere

2. Our farming practices have changed:
This is what farming used to look like and this is what it looks like today. Can anyone think of factors that have changed that might be bad for the lithosphere in the context of agriculture?

3. Impact of Intensive agriculture on soils:
Gigantic fields vulnerable to wind erosion in dry periods.
Fertilizers and pesticides threaten Biodiversity and kill microorganisms that help maintain soil balance.
Use of heavy machines:
compacting of soil, less oxygen available for microorganisms
Rain water does not sink it but runs off the surface carrying away soil and nutrients  water erosion
Reduce
soil fertility
Heavy machines compact soil  less oxygen, bad for miroorganisms  less humus production

4. Soil depletion is the loss of soil fertility

5. Contamination is the abnormal presence of a harmful substance in the environment
Hydrocarbons from oil spills and and leaky gas station tanks
Heavy metals from leaky land fills and industrial pollution
Acidic waste from mining

6. Contamination from the atmosphere
Sulfur dioxide (SO2) and Nitrogen oxides (NOx) from combustion of fossil fuels and other industry
carried by wind
Gases dissolve in rain
 Acid rain
What happens when acid rain hits the ground?

7. Effect of acid rain on lithosphere
Leaching of soil  minerals are dissolved and carried away with the water (washed out).
Mobilization of aluminum minerals  aluminum toxic for living organisms (particularly for plants)
Acidification of soil  upsetting of vegetation (some species prefer acidic soil and others can’t tolerate it  change in vegetation will occur)

8. Impact of acid rain depends on soil
A soil’s BUFFERING CAPACITY is its ability to resist changes in pH when acidic or alkaline products are added.
Soils with low buffering capacity more vulnerable to effects of acid rain
Sandy soil has a low buffering capacity
Silt and clay soils have a higher buffering capacity

9. Summary: Degradation / Pollution of the lithosphere
Soil depletion because of intensive farming:
large fields  more wind erosion
Use of pesticides and fertilizer  reduce biodiversity
Heavy machines  soil compacting, less oxygen, water erosion
Contamination by
hydrocarbons (gas stations, cars)
Heavy metals (leaky land fills)
Acid waste (from mining)
Contaminants from atmosphere (acid rain)
Work book page 104 # 3 and 4  soil depletion, contamination, buffering

10. Pollution and Contamination of water
Point sources
Pollution can be traced to well defined site.
Non point sources
Difficult to locate exact origin of pollution

11. Sources of Pollution and Contamination of water
Rain /
Acid rain:
acidifies water  some species more sensitive
Dissolves aluminum from aluminum minerals and transports it into rivers and lakes.  Aluminum toxic
Farming:
Run off water carries fertilizer and pesticides into water
Talked about itensive farming and the effects it has on our soil we had mentioned
Domestic and industrial sewage:
Organic and chemical pollutants
heat

12. Pollution and Contamination of water
Heat:
Solubility of Oxygen decreases with in-creasing temperature
Bad for animals and microorganisms.

13. Sources of Pollution and Contamination of water
Rain /
Acid rain:
acidifies water  some species more sensitive
Dissolves aluminum from aluminum minerals and transports it into rivers and lakes.  Aluminum toxic
Farming:
Run off water carries fertilizer and pesticides into water
Talked about itensive farming and the effects it has on our soil we had mentioned
Domestic and industrial sewage:
Organic and chemical pollutants
heat

14. Eutrophication
Process by which natural waters lose their oxygen because of an excessive accumulation of of organic matter and nutrients

15. Over time sediment accumulates in lake  Water becomes shallower.
Time: Centuries
Over time sediment accumulates in lake
 Water becomes shallower.
 More plant growth, more production of organic material.
 Bacteria decompose plant material, consuming large amounts of oxygen.

16.  High production of organic material
sediment
sediment
Time: Decades
Fertilizers form agriculture (particularly Phosphorus) and warming of water promote rapid growth of algae:
 High production of organic material
 Bacteria decomposing organic matter consume a lot of oxygen
warm water less oxygen than cold water

17. Effect of pollutants depends on:
Their concentration
Their nature (toxicity)
How long they will remain in the environment
 how quickly is water exchanged/ renewed
Which one will be affected more easily?
creek
Intro to slide: Aquatic ecosystems have ability to degrade and tolerate some contaminants. When system gets out of balance we say it is polluted
pond

18. Contamination of oceans with oil
Through:
Pumping of oil from under the ocean
Some leaks
Oil tankers clean out on open sea
accidents

19. Pollution and contamination of water
Point source vs. non point source
Contamination through:
Acid rain
Pesticides, fertilizer and manure from farming
Sewage, either domestic or industrial
Heat
Hydrocarbons, oil (in particular oceans)
Heat and fertilizer cause Eutrophication of lakes
Note taking sheet page109 questions Page 110

20. Notes on contamination of hydrosphere
Bill Ny clip herbicides and frogs
Clip herbicides and frogs

21. Contamination of the atmosphere
Green house gases
“acid rain” gases
( Clean rain pH ,7, acid rain pH 3-5.)
Heavy metals (mercury (Hg), arsenic (As), lead (Pb))
 from combustion of oil, coal, waste incineration
Chlorofluorocarbons (CFCs) – destroy Ozone
Smog
– CO2, H2O, N2O, CH4
– SO2 and NO, NO

22. Waste incineration, oil / coal combustion
Release Heavy metals into the atmosphere: (mercury (Hg), arsenic (As), lead (Pb))
toxic
Lead replaces other metals in enzymes but not functionally, in humans in particular enzymes involved in hemeproduction -> anemia

23. Where: In Stratosphere
Ozone layer
Ozone = O3; Chemical filter, absorbs UV…
… when created:
… when destroyed:
Where: In Stratosphere O2
Why do we have a hole in the ozone layer O3

24. CFCs destroy the Ozone layer
Chlorofluorocarbons
Look for:
Used in:
insulation foam
refrigeration and air
conditioning systems
in aerosols

25. How do CFCs act: 1 2 3 1. Release chlorine atoms
2. chlorine atoms destroy ozone 2
3. ClO catches oxygen atom and reproduces chlorine atom. 3

26. In 1987 …
Montréal Protocol to gradually phase out use of CFCs until 2010.
Prediction: Ozone layer will recover by the middle of this century (2050).

27. Smog
Thick mixture of fog (water vapor), smoke (particles) and atmospheric pollutants atmospheric pollutants: ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2)  can cause asthma. forms when high pressure system prevents gases from rising ozone very reactive molecule  harmful to our health when it enters our lungs
Notes on page 124

28. Note taking page 124 Homework: P. 110 all P. 126 # 4 P. 104 # 3, 4
Work book page 102 # ,5 page 104 # 3 and 4  soil depletion, contamination, buffering
Page 109 notes on hydrosphere contamination, page 110 questions,