Managing Pollution (AQA A Level Geography)

• Rapidly developing LDEs and EMEs have some of the highest rates of air pollution and reducing urban air pollution globally, is a challenge
• Strategies include:
  • Technical innovations
  • Vehicle restrictions
  • Government legislation
• Filters
  • Fitted to industrial gas and particulate exhausts, filters carbon out of the gases released during industrial processes
  • Any emitted gases are chemical and pollutant free when released back into the environment
  • Catalytic converters fitted to vehicle exhausts remove harmful pollutants before being released
• Photo-catalytic materials (smog eating material) 
  • Façades are retrofitted to the front of old buildings or new buildings are constructed with photocatalytic concrete
  • Special tiles are coated with titanium dioxide, which is a pigment that acts as a catalyst and is also used in sunscreen
  • When UV rays hit the tiles, a reaction occurs, converting mono-nitrogen oxides (smog producing substances) into less harmful calcium nitrate and water
  • Titanium dioxide within the tiles isn't altered and continues to work indefinitely
• Self-cleaning concrete - Tiocem
  • This is photocatalytic concrete that has titanium dioxide mixed in
  • Buildings will be able to break down nitric and nitrogen oxides when hit by sunlight
  • Can also be used for constructing paving, roofing tiles, roads, and in sound buffering walls on the sides of roads
    • Smog Eating Poem, - the University of Sheffield, UK, has dedicated one of its walls to a smog-eating  poem called In Praise of Air
    • The poem is printed on material infused with titanium dioxide that reduces air pollution
    • The banner removes the pollution of at least 20 cars every day
    • Following this, smog-eating advertising posters have begun appearing in other parts of the world, including a mural made of photocatalytic paint pigments in Warsaw, Poland 
• Greening the urban area
  • Improve air quality through planting trees and vegetation
  • Vertical gardens -  around concrete columns and on the sides of buildings
  • Roof gardens 
  • Urban agriculture using open and derelict spaces
• Air purification towers
  • Dutch designed “Smog Free Tower” which is an air purifying tower that sucks in pollution and expels clean air
  • The first tower was installed in Rotterdam, and cleans 3.5 million cubic metres of air per day
• Self-driving cars
  • Studies have estimated that self-driving vehicles could improve fuel efficiency by 15-40%, which would reduce local emissions of pollutants as well as global greenhouse gases
• Hydrogen fuel additives 
  • Additives improve fuel combustion and reduces emissions in existing vehicles
  • UK developed 'ezero1' technology feeds small amounts of hydrogen into the vehicle air intake, creating a more efficient burn
  • By increasing fuel efficiency, there is an overall reduction in nitrogen oxide (NOx), particulate matter (PM), hydrocarbon and carbon monoxide emissions
  • The technology can be retrofitted to existing vehicles and is available commercially in small numbers
• Alternative fuels
  • Electric 
    • Hybrid electric vehicles (HEVs)
    • Plug-in hybrids (PHEVs)
    • Fully electric (EVs)
  • LPG
    • Dual fuel or bi-fuel vehicles that can switch between LPG and petrol
    • LPG is a by-product of the crude oil refining process 
    • Contains a mix of hydrocarbon gases and considered having a relatively low environmental impact
    • LPG has many uses from cooking to heating, refrigeration to vehicle fuel
  • Synthetic “gas to liquid” (GTL)
    • Shell has developed a new GTL fuel as a replacement for diesel and the engine needs no modification
    • Testing of GTL in heavy vehicles (trucks, buses and ships etc.) and depending on the vehicle age, showed reduced nitrogen oxide (NOx) emissions of 5-37%, and particulate matter (PM) emissions of 10-38%, 
  • Natural gas can also be converted into dimethyl ether (DME) as another alternative to diesel
    • Although the engine needs modifying, using DME reduces NOx emissions by around 25% and PM emissions virtually eliminated
    • Car makers Ford and Volvo, are considering marketing vehicles already able to use DME as a fuel

• Congestion charge
  • Charges for using vehicles in certain places at certain times (e.g. London's congestion charge)
  • This reduces pollution through the reduction in road traffic (London's emissions dropped 15% in its first year)
  • However, it can increase fringe/outer zone traffic and emissions as people try and avoid the charge by using alternative routes
• Selective bans
  • Certain days and times are designated as no travel times for vehicles
  • Mexico City's air quality is among the worst in the world, according to the World Health Organization (WHO)
  • Over 5 million cars within a valley with a population of more than 21 million people
  • The city instituted a late start for schools 10am instead of 8am
  • No car day, where commuters are banned from using their car depending on the last digit of their number plate (e.g. on Mondays, plates ending in 5 or 6 cannot be used)
• Pedestrianisation
  • Vehicles are restricted from entering certain places at certain times
  • This reduces emission by reducing road traffic
  • Many urban areas have pedestrianised zones, however, it impacts retailers as restrictions on parking can discourage customers
• Park and ride 
  • Buses are laid on by local authorities at the urban fringe and charge a flat fee for all day parking and travel from the parking area to the urban centre
• Improvements to public transport
  • Improved bus services makes accessing areas cheaper, faster and more efficient
  • Many cities have brought in bus lanes, which keeps the buses moving in peak traffic times
  • Trams and light railway services run on lines that avoids congestion
  • Less polluting than buses and can be accessed at various points on the journey
  • Not always successful and can shift congestion issues to the urban fringe
  • Improvements can be very expensive and run over time and budget (e.g. HS2)
• Car sharing/pooling
  • Many urban centres have designated lanes for cars with two or more people in them
  • This keeps the flow of traffic moving and reduces journey times and emissions

• Legislation can be local or global
• However, according to the UN

One in three countries in the world lack any legally mandated standards for outdoor air quality - UNEP 2021

• Laws aim to reduce pollution by limiting emissions from industry, private and public facilities and vehicles
• Industries are are regulated under Integrated Pollution Prevention and Control (IPPC) set up under the Pollution Prevention and Control Act of 1999
  • Factories are not allowed to emit 'dark' smoke under the Clean Air Act of 1993, except in unavoidable circumstances (e.g. starting up)
  • The amount of dirt and dust emitted is also strictly monitored/controlled
  • Chimneys must have up-to date modern filters/scrubbers fitted
• In the UK, key air pollutants are regulated by the Air Quality Standards Regulations 2010
• Laws set air quality standards such as:
  • UK Clean Air Act of 1956 and 1968 reduced domestic pollution through the introduction of smoke free zones
  • Industrial pollution was reduced by introducing tall chimney thereby dispersing pollutants higher into the atmosphere
  • Introduction of the MOT emissions test by the Road Vehicles Regulations means all vehicles have to pass an emissions test to be allowed on the UK roads
  • In Scotland, roadside emissions tests are carried out and fines issued if the vehicle fails
  • Local authorities in the UK can issue fines to people leaving their engines running unnecessarily