Environmental Issues in Urban Areas

1. Environmental Issues in Urban Areas

2. Main Causes Vehicle exhausts Industrial emissions Emissions from power stations Domestic Homes Main Dangers Nitrous oxides - In bright sunshine this undergoes a chemical change to form a photochemical smog – and causes a serious health hazard to people, plants and animals – good examples are Ozone – This sensitises the body to irritants such as house dust or pollen – affecting breathing Carbon Monoxide – Caused by the incomplete combustion of fuel – effects are headaches, fatigue, drowsiness and even death Sulphur Dioxide – Produced from cars – it irritates eyes and aggravates asthma and the respiratory system Suspended Particles such as dust, cement, pollen, organic compounds and petrol all affect the respiratory system Air Pollution

3. Case Study – Mexico City Reputed to be the worst polluted city in world Caused by Industrial, car and the choking dust blown across the city as well as mountains that surround it Plans to reduce pollution Build a new underground system To develop bus transport but lack of money is a problem Introducing ‘the no drive today policy which bans certain cars being used How successful? & Why? Not really due to the number of vehicles increasing and enforcement is difficult Solutions in other Areas Catalytic Converters Lead Free Petrol Sulphur free fuels All the strategies for reducing transport in cities including congestion charging, Park and Ride, Bus Lanes, etc Develop cleaner transport Electric Cars LPG powered cars/dual use e.g. Bristol Buses Tax cars with high emissions Answer Q1, 2 & 3 page 250 How can the strategies vary between MEDC’s & LEDC’s Give reasons for your answer

4. In MEDC’s – Britain In England & Wales in 1990, 89% of rivers and canals were of good water quality In 1991 there were 30,000 reported pollution incidents Main Causes Sewage disposal – Most sent to treatment works where waste products are removed – the effluent left should comprise of 95% waste water and is discharged into rivers. Also 25% of country still not served by sewage treatment works Agricultural run-off – Farm waste and slurry effluent are normally spread on farmland but due to heavy rain and accidents can lead to them reaching a river. Undiluted farm slurry is 100 times more polluting than raw sewage Silage effluent is 200 times more polluting Both use up large amounts of oxygen to break them down and results in damage to plants & animals Fertiliser-nitrates resulting in eutrophication Water Pollution

5. Water Pollution - Causes • Industrial Discharge – Some Industrial waste is discharged directly into the river – with some being very harmful especially in the case of chemicals – see video of Rhine for information. • Power Stations – Many power stations extract water for cooling purposes before returning it to the river. Although the water is not polluted, as it is considerably warmer than before it contains much less oxygen and therefore harmful to river life. • Landfill Sites – Pollutants from waste landfill sites can leach slowly into the rivers

6. Causes Answer Question 1 page 253 Using page 250 outline the main causes of water pollution in LEDC’s – how does this differ to MEDC’s Case Study – The Ganges Read the information on The Ganges from the separate sheet & page 253 Outline the main causes of pollution in the Ganges. What is the GAP and how is it trying to improve water quality in the Ganges. Water Pollution in LEDC’s