IB Environmental Systems and Societies

1. Topic 5
Pollution Management
5.3 Approaches to pollution management

2. Causes of Pollution
• Non-anthropogenic
– Volcanic activity
• Anthropogenic
– Agricultural runoff
– Industrial effluents and
solid wastes
– Sewage effluent
– Combustion of fossil
fuels
– Landfill leachates
– Pesticides

3. Pollution Management Strategies
• Education and changing attitudes
– e.g. Prevention of pollution through increased use of
renewable resources and recycling
• Regulation
– e.g. Government or regulatory bodies may require
removal of pollutants at the source of emission –
desulphurisation of flue gases at power stations
• Cleaning up
– e.g. Cleaning of coastline and animals after oil spills
– Expensive, time-consuming and labour intensive
• Integration of policies
– A combination of all of the above approaches

5. Human Factors
• The choice of pollution management strategy
depends on other factors such as:
– Economic resources
– Cultural values
– Political systems
http://www.youtube.com/watch?v=wT-zABFlrE0
http://www.youtube.com/watch?v=p9VEj-cmb6w

6. Case Study: DDT
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Dichlorodiphenyltrichloroethane
An organochlorine insecticide
Very non-polar
Similar in structure to oestrogen and therefore has
´feminising’ effects on animals
In birds it weakens egg shells so that the parents
break them as they try to incubate the eggs
The birds at highest risk are those close to the top
of the food chain
It was banned in most developed countries in the
1970s and 1980s
It is now known to cause birth defects, damage to
the nervous system and cancers
It is still used in many poorer countries to control
insect problems – why?
http://edroness.blogspot.mx/2013/10/biomagnification.html
http://edroness.blogspot.mx/2013/10/the-story-of-ddt.html

7. ‘Silent Spring’
• Silent Spring is a book first published
in 1962 by marine biologist Rachel
Carson
• It was largely about the effects on
top predator bird populations (such
as eagles) which she claimed were
being affected by the indiscriminate
use of DDT
• It was so influential she effectively
kick-started the modern
environmental movement

8. Questions
1. Outline 3 possible strategies for reducing
pollution
2. Outline human factors that affect pollution
management
3. Describe the variations in the concentration
of DDT at different levels in the food chain
4. Outline the main uses and the risks of using
DDT as an insecticide