1. IB3.24.3 Pollution © Oxford University Press 2011 Pollution

2. IB3.24.3 Pollution © Oxford University Press 2011 Pollution can affect land, air, and water. Can you give examples of each?

3. IB3.24.3 Pollution © Oxford University Press 2011 Air can be polluted by smoke and gases such as sulfur dioxide.

4. IB3.24.3 Pollution © Oxford University Press 2011 Land can be polluted by waste going to landfill sites.

5. IB3.24.3 Pollution © Oxford University Press 2011 Water can be polluted by sewage, pesticides, and other human activities.

6. IB3.24.3 Pollution © Oxford University Press 2011 PollutantSourceEffect on environment Untreated sewage Sewage works FertilisersFarms Pesticides and herbicides Farms Toxic chemicals Factories and mining DetergentsDomestic use OilTankers and pipelines Water Pollution

7. IB3.24.3 Pollution © Oxford University Press 2011 PollutantSourceEffect on environment Untreated sewage Sewage worksBacteria can cause disease, e.g typhoid and cholera. Nitrates in the water lead to the death of fish by a process called eutrophication. FertilisersFarmsNitrates in the water (as above). Pesticides and herbicides FarmsThese chemicals are washed into waterways and may build up in food chains to toxic levels. Toxic chemicals Factories and mining Poison organisms directly, or may build up in food chains to toxic levels. DetergentsDomestic useKill valuable microbes. OilTankers and pipelines Kills birds and fish. Pollutes the sea bed. Water Pollution