Summary of topic 5.3

Topic 5Pollution Management

5.3 Approaches to pollution management

Causes of Pollution

• Non-anthropogenic– Volcanic activity

• Anthropogenic– Agricultural runoff– Industrial effluents and

solid wastes – Sewage effluent– Combustion of fossil

fuels– Landfill leachates– Pesticides

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

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-zABFlrE0http://www.youtube.com/watch?v=p9VEj-cmb6w

Case Study: DDT• 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.htmlhttp://edroness.blogspot.mx/2013/10/the-story-of-ddt.html

‘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

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