Pollution and Degradation of the Lithosphere, Hydrosphere and
Atmosphere
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Our farming practices have changed:
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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
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Soil depletion is the loss of soil fertility
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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
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Contamination from the atmosphere Sulfur dioxide (SO 2 ) and
Nitrogen oxides (NO x ) from combustion of fossil fuels and other
industry carried by wind Gases dissolve in rain Acid rain
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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 cant
tolerate it change in vegetation will occur)
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Impact of acid rain depends on soil A soils BUFFERING CAPACITY
is its ability to resist changes in pH when acidic or alkaline
products are added. Sandy soil has a low buffering capacity Silt
and clay soils have a higher buffering capacity Soils with low
buffering capacity more vulnerable to effects of acid rain
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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)
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Point sources Pollution can be traced to well defined site. Non
point sources Difficult to locate exact origin of pollution
Pollution and Contamination of water
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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 Domestic and industrial sewage: Organic and
chemical pollutants heat
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Heat: Solubility of Oxygen decreases with in- creasing
temperature Bad for animals and microorganisms. Pollution and
Contamination of water
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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 Domestic and industrial sewage: Organic and
chemical pollutants heat
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EUTROPHICATION Process by which natural waters lose their
oxygen because of an excessive accumulation of of organic matter
and nutrients
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sediment 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.
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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
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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? pond creek
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Contamination of oceans with OIL Through: Pumping of oil from
under the ocean Some leaks Oil tankers clean out on open sea
accidents
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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
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Notes on contamination of hydrosphere Clip herbicides and
frogs
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Contamination of the atmosphere Green house gases acid rain
gases ( Clean rain pH 5.5 -5,7, 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 CO 2, H 2 O, N 2 O, CH 4 SO 2 and NO, NO
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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
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Ozone layer Ozone = O 3 ; Chemical filter, absorbs UV when
created: when destroyed: Where: In Stratosphere O2O2 O3O3
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CFCs destroy the Ozone layer CFCs = Chlorofluorocarbons Used
in: insulation foam refrigeration and air conditioning systems in
aerosols Look for:
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How do CFCs act: 1 1. Release chlorine atoms 2. chlorine atoms
destroy ozone 2 3. ClO catches oxygen atom and reproduces chlorine
atom. 3
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In 1987 Montral Protocol to gradually phase out use of CFCs
until 2010. Prediction: Ozone layer will recover by the middle of
this century (2050).
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Smog Thick mixture of fog (water vapor), smoke (particles) and
atmospheric pollutants atmospheric pollutants: ozone (O 3 ),
nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ) 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
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Note taking page 124 Homework: P. 110 all P. 126 # 4 P. 104 #
3, 4 http://www.youtube.com/watch?v=kdDSRRCKMiI