Other Contemporary Urban Issues

• In Shenzen, China, three-quarters of the complaints about pollution are about noise pollution rather than air or water pollution
• Atmospheric Pollution

  • Caused by release of particles and noxious gases
  • In 2014, WHO found air pollution was 2.5 times higher than recommended in a majority of urban areas
  • Air pollution accounts for an estimated 4.2 million deaths due to stroke, heart disease etc.
  • Around 91% of the world's population lives in places where air pollution exceeds WHO limits
  • An estimated 3800 people in London died prematurely from air pollutants
• Managing Air Pollution

  • Ensuring houses are energy efficient
  • Urban development well served by public transport
  • Street design safe and appealing for pedestrians and cyclists
  • Waste well managed
• London's 8.3 million trees provide £95 million worth of air filtration every year in terms of health costs avoided
• In LICs there is a lack of finance and legislation to tackle pollution. Over 90% of air pollution is attributed to vehicle emissions due to the high number or poor vehicle maintenance and fuel quality
• Water pollution is the contamination of water sources including rivers, lakes and aquifers. Occurs when pollutants are discharged into water without adequate treatment
• The high concentration of impermeable surfaces in urban areas increases run-off from roads and can carry numerous pollutatnts such as oils and heavy metals into waterways
• Causes of Urban Water Pollution

  • Surface run-off from streets carrying oil, heavy metals and other contaminants
  • Industrial waste
  • Untreated or poorly treated sewage which is low in dissolved oxygen and high in pollutants such as nitrates
  • Rubbish dumps, toxic waste, chemicals and fuel storage
  • Dumping of hazardous substances
• Consequences of water pollution

  • Heavy metals from industrial processes can slow development and result in birth defects
  • Industrial waste often contains toxic compounds that damage the health of aquatic life and those who eat them
  • Microbial pollutants from sewage result in diseases such as cholera and typhoid
  • Organic matter and nutrients can cause an increase in aerobic algae and deplete oxygen
  • Suspended particles in freshwater reduce the quality of drinking water
• In HICs, water quality improvement focuses on:

  1. the construction of water treatment facilities and wastewater plants
  2. regulations aimed at 'point source' polluters such as industries which discharge water pollution into sewer systems that flow into treatment plants
• The most difficult water quality challenge is dealing with non point-source pollution which is the result of precipitation run off from a wide range of sources
• Low Impact Development

  • Helps reduce stormwater run-off
  • Done through the use of vegetation and permeable surfaces to allow infiltration of water into the ground
  • Permeable streets and pavements allow water to infiltrate the soils rather than flow directly into sewers
  • This process has been shown to reduce organic pollutants by over 90%
• Legislation, regulation and enforcement

  • Many different anti-pollution laws and agreements in operations
  • Some cities off incentive-based approaches, charging polluters
  • Charges start low but increase if pollution continues
  • Regulation allows limited amounts of discharged pollutants, and this decreases each year
• Education and awareness

  • The more people know about the causes and effects of pollution, the more likely they are to avoid the problem
  • 2014 Wessex Water used mobile billboards in hotspot areas encouraging people to bin wet wipes, not flush them
• Appropriate Technology

  • e.g the Janicki omniprocessor which aims to provide clean water in LICs
  • First boils raw 'sewer sludge' during which the water evaporated separates from the solids
  • Solids are put into a fire to generate electricity
  • Water is cleaned to drink
• The Thames Tideway Tunnel

  • Most of London served by combined sewage system including housing sewage and rainwater runoff as created by Joseph Bazalgette
  • During periods of heavy rain, the sewers discharge raw sewage into the river Thames
  • In 2013, 55 million tons of raw sewage was washed into the river
  • Thames Tideway Tunnel is a tunnel 7 metres in diameter with a concrete wall which will take sewage to the Becton sewage treatment in Essex
• Dereliction = the state of having been abandoned and become dilapidated
• In urban areas, derelict buildings are often associated with former industrial sites or run-down housing estates, in the UK, deindustrialisation led to many people leaving to inner city and industrial buildings being abandoned
• Dereliction has a negative impact on the surrounding area, crime and vandalism rates tend to be higher and price houses fall and out-migration of residents takes place
• High costs involved in urban renewal often discourage authorities from renovating or rebuilding, and the presence of listed building can increase investment needed due to required planning regulation
• Derelict land can pose a risk to human health. In Glasgow, research has linked proximity to contaminated derelicit sites with health problems such as heart disease and low birth weight infants
• One of the most common strategies for tackling urban dereliction is through regeneration schemes. UK government led schemes such as urban development corporations and city challenge have has varying levels of success in tackling derelict areas
• The government focus on using brownfield sites for new building developments rather than greenfield sites, but this doesn't always work. The proportion of homes being built on the green belt doubled from 2 to 4% between 2016 and 2017, whilst the amount built on brownfield fell from 61 to 56%
• Brownfield Sites = Land previously used for industrial purposes or some commercial uses
• Greenfield site = Area of undeveloped land
• Advantages of building on brownfield sites

  • Improves physical environments
  • Revives older communities
  • Existing infrastructure can reduce costs and encourage occupancy
  • Reduces urban sprawl
  • Preserves green space
• Disadvantages of building on brownfield sites

  • Greater cost of clearing contaminated land
  • Have higher levels of traffic congestion
  • Noise pollution
• Land Remediation

  • Removal of pollution or contaminants from the ground
  • In preparation for the 2012 London Olympics, a 350 hectare area of East London was 'cleaned up' and is now the largest urban park in Europe
  • Over 2.2 million square metres of soil was excavated, treated by soil washing, chemical stabilisation and bioremediation
• Community Action

  • At the heart of Detroit's recent strategy to tackle derelict land
  • Population fell from nearly 2 million in 1950s to less than 1 million now
  • City has 40,000 vacant and derelict lots, comprising 1/3 of its area
  • Detroit community groups are using areas for community based activities such as farming, bu 2010, they had converted over 7 hectares of unused land into over 40 community gardens and microfarms producing honey, eggs, milk etc.