DEFINITIONS TOPICS 5, 6, 7
Topic 5 Pollution Management
1. pollution – contamination of the Earth and atmosphere to such an extent that
normal environmental processes are adversely affected.
IB DEFINITION –
the addition to an environment of a substance/an agent (e.g. heat)
by human activity;
at a rate greater than that at which it can be rendered harmless
by the environment;
and which has an appreciable effect on the organisms within it;
2. point source pollution - source of contaminants that can be represented by
a single point on the map and the source can be tracked. Example : Industrial
plants the discharge pollutants into a river. You know exactly where the source
and can track it. Easier to manage.
3. non-point source pollution – more dispersed and difficult to track. Example :
air pollution in general. Difficult to track exact place it occurs; could be cars,
buses, buildings etc. More difficult to manage. Example RUNOFF – pesticides
and other pollution that gets into the run off water cycle. Difficult to determine
where it came from.
4. Eutrophication – due to increase of N or P in water causes increase of
nutrients in water especially for plants. This causes too much plant growth than
normal causing algae blooms ( large masses of plant and alga growth). Although
plants will produce O2 during the day via photosynthesis plants also “ RESPIRE”
– absorb O2 at night via photorespiration. This will decrease overall DO. Too
much plant growth on surface of lakes etc. will also block sunlight getting to
bottom of lakes reducing photosynthesis.
Eutrophication = HIGH BOD ( biochemical oxygen demand) = ORGANIC
POLLUTION
5. BOD – Biochemical oxygen demand. Basically the demand for oxygen in a
river by aerobic organisms. Does not measure O2 produced by photosynthesis.
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6. Biotic index – index that show pollution based on diversity of species present.
As pollution increases, diversity decreases.
7. Direct method of monitoring pollution – measuring a specific substance
that directly indicates pollution. Example: air pollution - : sulfur dioxide, nitrogen
oxides, ozone, particulate matter.
8.Indirect method – measuring organisms that indirectly relate to pollution.
Example BOD and Tubifex worms.
9. DO – Dissolved Oxygen
as salinity, temp. increases, DO decreases. Salt “ dehydrates “ water and
removes DO. Higher temp. increases kinetic energy and causes O2 to move
around more and may evaporate so overall conc. of DO goes down.
Atmospheric pressure above water affects DO. As press. Above water increases
it “ pushes O2 into water and increases DO. At higher elevations there is less atm
press. so less DO in general.
pH – decreases or increase of pH away from neutral 7.0 generally lowers DO
due to acid base reactions.
Photosynthesis by plants etc. increases DO and respiration by organisms in
water decreases DO.
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10. Pollution Management
What you need to know from this section is the following flow chart and examples
of each :
11. Explain bioaccumulation and biomagnification.
Bioaccumulation – retention and build up of non-biodegradable chemicals in the
body.
Biomagnification – concentration of a chemical increases at each trophic level.
Top predators may have concentrations of a chemical several million times
higher than the primary producer.
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12. Clean up strategies. List the main clean up methods.
IB Qs – Clean up and Eutrophication
1. Describe and evaluate management strategies to restore a eutrophic lake.
Describe:




add aerators to the lake (to maintain survival of species)
remove aquatic plants during their growing period
dredge the mud from the bottom of the lake to remove nutrients
introduce species of fish which consume algae;
Evaluate:




aerators are expensive to operate
aerators do not reduce the pollution problem, so must be
used continuously;
aquatic plants which have been removed from the lake transfer
the nutrient overload to another ecosystem;
mud pumped from the lake transfers nutrient overload to
another ecosystem;
2. Development of a tourist resort near a lake is proposed. Outline strategies for
determining the environmental impact of the development on the lake.




Environmental Impact Assessment/EIA/baseline study must
occur before any development begins
select biological (species diversity) biotic index to test abundance of
species in relation to pollution. Tubifex worms, may flies, carp fish (
low DO) and trout fish ( high DO). Compare DO and BOD.
Select chemical (nutrient status) indicators to test : nitrates,
phosphates.
monitoring of the environment must continue at regular intervals
during and after development
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13. Types of solid domestic waste - Know the following table
Material type
Examples
Organic material
garden waste, food/kitchen waste, wood
Paper
newspaper, writing paper, packaging,
cardboard, milk cartons
Plastics
soft drink bottles, plastic bags, plastic containers
Glass
jars, bottles, plate glass
Metals
steel cans, aluminium packaging and
cans, copper pipes
Household hazardous
paint, dry cell batteries, car batteries, fluorescent
light bulbs
Miscellaneous
ceramics (bricks, tiles etc.) rock, ash, soil
14. Pollution Management Strategies
There are a number of methods of dealing with solid domestic waste. The most
common ones include recycling, reuse, reduce, composting, landfill, and
incineration
15. Composting
1. Define composting – aerobic decomposition of BIODEGRADABLE
material.
2. How does it help in terms of recycling? It recycles organic household
waste into humus-like soil. It returns valuable nutrients to the soil.
16. Depletion of Stratospheric Ozone
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IB Qs OZONE : True or False : mark T or F . If false rewrite statement to make
it true:
1.
Ozone gas is increasing in the upper atmosphere through the action of CFCs –
F ; decreasing
2.
Ozone gas is increasing in the upper atmosphere because of global warming –
F ; decreasing
3.
Ozone gas is decreasing in the upper atmosphere because of the increase in the
amount of nitrogen oxides produced by the combustion of fossil fuels – T see
text p. 246
4.
The formation of ozone involves the absorption of ultra-violet radiation – T
see text p. 243 : UV radiation breaks down oxygen atoms to combine with O2
resulting in O3 = ozone.
5.
The type of ultra-violet radiation absorbed by the ozone layer does not affect
living organisms – F does affect
6.
Chlorofluorocarbons in the stratosphere are rapidly broken down allowing
them to escape into the outer atmosphere – F p. 244 : rapidly broken down by
UV radiation in stratosphere allowing them to release Halogen atoms ( Cl, F
and Br).
17. Urban Air Pollution –VOCs, Nitrogen Oxides,
1. What are the common names for the troposphere and stratosphere?
Lower atmosphere , upper atmosphere
2. What is the difference between ozone found in the troposphere versus
that found in the stratosphere? ( include how each is formed in your
explanation)
Ozone in troposphere is a pollutant and forms as a result of pollution by volatile
organic compounds ( VOC’s) , hydrocarbons and nitrogen oxides ( NOx )
Ozone in stratosphere is considered a protective layer against UV radiation. It is
formed by sunlight ( UV radiation) splitting oxygen molecules into atoms which
regroup to form ozone.
3. What does VOC stand for? How do they react? List some examples.
volatile organic compounds – evaporate into gases and take part in
photochemical reactions. Methane, ethane and alcohol
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4. Nitrogen Oxides : remember that these can also deplete ozone ( ODS –
ozone depleting substances) in the stratosphere ( upper atmosphere) although
they help form the ozone in the troposphere ( lower atmosphere).
5. Use the following to explain the reaction that causes urban haze commonly
known as smog: fossil fuel, nitrogen monoxide, oxygen, and nitrogen dioxide.
Fossil fuels burn and produce nitrogen monoxide. Nitrogen monoxide reacts with
oxygen in the air to produce nitrogen dioxide a brown gas that contributes to
urban haze – smog.
6. List damage done by tropospheric ozone on crops and humans: damages
crops, irritates eyes, causes breathing difficulties, susceptibility to infection. It is
highly reactive and can attack fabrics and rubber materials. Can cause up to 15%
reduction in lung capacity in children born and raised in areas of high level of
ozone.
18. Photochemical Smog
Photochemical smog is a mixture of pollutants that are produced when nitrous
oxide, tropospheric ozone and VOC’s react with SUNLIGHT ( thus , the name
photochemical). The frequency and severity of photochemical smog depend on
local topography, climate, population density, fossil fuel use and traffic. Low wind
speed and thermal inversion can trap the smog in valleys ( for example Los
Angeles, Mexico City, Rio de Janeiro , Sao Paulo and Beijing) and
concentrations of air pollutants can build to harmful and even lethal levels.
Thermal inversion – when the temperature at the surface is colder than above.
The air becomes more dense and tends to trap the photochemical smog.
19. Know the Following:
Major Green house gases : water vapor, CO2 , nitrous oxide, methane, CFCs
and ozone.
ODS ( Ozone depleting substances) : halogenated organic gases ( examples :
CFCs – chlorofluorocarbons, HFCs – hydrofluorocarbons) , nitrous oxides,
Freon – CFC found in refrigerators.
Acid rain : caused by sulfur dioxide and nitrous oxide
NOTE: Nitrous oxide is not a halogenated gas ( halogen = Cl, F, Br and I) but
does deplete ozone and is considered and ODS.
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20. Know the following table:
Sulphur
dioxide
Halogenated
gases
Methane
Carbon
dioxide
increases the
greenhouse effect
No
Yes
Yes
Yes
depletes
stratospheric ozone
No
Yes
No
No
increases acidity
of rain
Yes
No
No
No
21. Acid Deposition - Acid Rain
22. In general, leaching is the extraction of certain materials from a carrier into a liquid (usually, but not
always a solvent). Specifically, it may refer to:


Leaching (agriculture), the loss of water-soluble plant nutrients from the
soil
Acid rain leaches calcium and other nutrients - minerals form the soil
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Topic 6 Global Warming
23. Major Green house gases : water vapor, CO2 , nitrous oxide, methane,
CFCs and ozone.
24. Effects of Global Warming 






trapping of heat in the lower atmosphere, by preventing long wave
radiation escaping
thermal expansion of the oceans
melting of ice-caps (e.g. Greenland/Antarctica)
retreat of valley glaciers (Alps, New Zealand)
long-term rise in sea-level/flooding of lowland areas/low islands
change in the distribution of world biomes
extreme weather phenomena
25. Albedo – amount of radiation that is reflected by the earth’s surface back into the
atmosphere ( mainly due to polar ice caps).
26. Carbon Taxes and Trading
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27. Feedback Mechanisms
Example: Of what is the diagram below an example? B
ice-caps melt
global warming
less energy refected
increased global temperature
A.
Negative feedback
B.
Positive feedback
C.
Steady-state equilibrium
D.
Static equilibrium
Topic 7 Environmental Value Systems
28. Environmental Value Systems –
issues.
29. Ecocentric view point – nature centered and do not trust technology.
30. Technocentric view point – technology will provide solutions to
environmental problems.
31. Anthropocentric view point – in the middle and include both technocentric
and ecocentric viewpoints.
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