Transcript Pollution - Mrs. O` Hehir`s Biology Site

Ch 5 Human Impact on an
Ecosystem 1
Pollution
Need to know
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Define the term: Pollution.
State areas affected by pollution.
State mechanisms to control pollution.
Explain the difference between the
terms pollutant and pollution.
• Discuss the ecological impact of one
human activity.
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Human Impact on Ecosystems
We are going to look at 3 ways that
humans affect ecosystems:
1.Pollution
2.Conservation
3.Waste Management
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Pollution
• Pollution is the addition of harmful
substances to the environment.
• It is the most harmful human impact and
affects air, fresh water, sea, soil and land.
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Some Types of Pollution
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Domestic Pollution
Industrial/Air Pollution
River/Water Pollution
Agricultural Pollution – slurry, if it gets into
a river/pond
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Pollutants
are substances that cause harm to the
environment.
• CO2 from burning fossil fuels
• SO2 from factory chimney
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Pollutants
• Some pollutants are normally present in
an environment, e.g. CO2
• but levels are increased by human
activity.
• Other pollutants never exist in an
environment e.g. oil slick, CFCs
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Learning Check 1
1. Explain the term Pollution.
2. Name some Types of Pollution.
3. Explain the term Pollutant.
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Effect of one pollutant from one area
- Agricultural, Industrial or Domestic
Area
Pollutant
Source
Effects
Slurry &
Agricultural
Fertiliser
Washed or Formation of algal
leached
blooms and
from land eutrophication
Sulphur
dioxide
Burning
Forms ‘acid rain’
fossil fuels
Industrial
Domestic
Plastic bags Shopping
Non-biodegradable
Suffocate small
animals, Litter11
Eutrophication & Algal bloom
• Eutrophication: a condition where lakes
become over-enriched with nutrients, resulting
from excess artificial fertilisers washed into
rivers and lakes.
• There is a rapid increase in the growth of alga algal bloom as they use up the nutrients.
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Eutrophication & Algal bloom
• When all the nutrients are used up the algae
die and are broken down by bacteria, which
use up the oxygen in the water resulting in
the death of aquatic organisms such as fish.
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• Eutrophication animation
• Water Pollution
• Water pollution - Kate Bush
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Control of Pollutants
in the selected area - Agricultural, Industrial or Domestic
Area
Pollutant
Agricultura Slurry &
l
Fertiliser
Control Measures
Avoid spreading these:
• on wet, waterlogged, frozen or
steeply sloping land
• within 1.5m of any
watercourse.
Industrial
Sulphur
dioxide
Fit catalytic scrubbers in
factory chimneys
Domestic
Bag tax/levy.
Plastic bags
Reuse/Recycle bags
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Learning Check 2
1. Explain the term Eutrophication.
2. Explain the term Algal bloom.
3. Give an example of a method used to Control
Agricultural Pollutants.
4. Give an example of a method used to Control
Industrial Pollutants.
5. Give an example of a method used to Control
Domestic Pollutants.
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Ecological impact of one human
activity
–
Industrial Pollution
Burning Fossil Fuels
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Acid rain
• Burning of fossil fuels releases acidic oxides
into the air - Sulphur dioxide (SO2) and nitrogen
oxides.
• SO2 dissolves in rainwater to form sulphuric
acid (H2SO4)
• The resulting rain is very acidic – pH 4.0,
normal rain water - pH 5.5.
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• Video on Coal-Combustion-and-Acid-Rain
• Air pollution Facts
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From 1997 to 2006 the EU-27 recorded a 28 %
decline in weighted emissions of acidification gases.
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Effects of Acid Rain
1. Causes soil to become more acidic.
2. The lower pH causes minerals e.g. Al, K, Ca
and Mg, required for normal plant growth to
be washed (leached) from the soil into lakes
and water supplies.
3. Soil becomes impoverished and fish die in
highly mineralised water.
4. Inhibits chlorophyll formation.
5. Burns the leaves of plants.
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6. Erodes limestone buildings
7. Causes breathing difficulties – irritates the
delicate lining of the lungs
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• Effects of acid rain & global warning
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6. Erodes limestone buildings
7. Causes breathing difficulties – irritates the
delicate lining of the lungs
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Dealing with acid rain
1. Reducing the quantity of fossil fuels burned.
2. Using catalysts to treat chimney gases
(scrubbers are fitted to the insides of
chimneys).
3. Catalytic converters fitted to modern cars.
4. Developing alternative ‘clean’ energy sources.
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Learning Check 3
1. What is acid rain?
2. How is acid rain formed?
3. List some of the effects of acid rain.
4. How can the probloms dealing with acid
rain be controlled?
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END
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