Urban Air Pollution

• Impacts: carbon monoxide causes heart problems/headaches; enhanced greenhouse effect; nitrous oxides cause respiratory problems and acid rain.
• Smog: in a basin, warm anticyclonic air traps cooler air and the pollution from the city forming smog.
• Smog - occurs when smoke particulates and sulpher dioxide from burning coal mix with fog.
• Photochemical smog - caused by sunlight reacting chemically with industrial and vehicle emissions to form secondary gases.
• Anticyclones - area of high pressure (eg in a basin), then descending air piles up/collects on the surface. They are infrequent and last for days/weeks.
• ULEZ - ultra low emission zone in london.
• UK air quality targets are set by 'department for environment, food, and rural affairs'. (DEFRA)
• Vehicle restrictions - pedestrianise city center.
• Technology means factories can use filters to reduce harmful emmissions.
• Clean Air Act was in 1956.
• Mongolia's Capital Ulaanbaatar: in winter coal stoves and power plants release diesel fumes. Cause limited visibility, acrid smell and respiratory problems. 2019 - schools closed for 2 months.
• Ulaanbaatar: rapid and unplanned growth. People stay inside - mental/physical impact on children. Lack of water/electric infrastructure. Mainly migrants are living in small tents heated with coal.
• Ulaanbaatar: mountains trapp pollution. 24 times the acceptable level for pollution.
• Condensation nuclei - dust/pollution acts as condensation nuclei, which attracts moisture and forms clouds. (so cities have more cloud cover).
• London are managing air pollution with: Congestion Charge, Low Emmission Zone, Santandar bikes and hybrid buses.
• London Congestion Charge: 15 pound daily, in certain times. Discounts for greenest cars and taxis/buses.
• Benefits of congestion charge: traffic has reduced; bus passenger and cyclists increased, decreased emissions.
• Santander Bikes: continually growing in amount of hires year on year. Low cost and are quicker than public transport. Intended for short journets. Have helped reduce emmissions.
• Hybrid Buses: diesel and electric. Reduced emissions in london. Are quieter and more Fuel efficiant.
• Mexico City: in a basin. Half of cars are allowed in on certain days, the other half on other days. Operated via number plates.