2019 Case Studies in Urban Air Quality

December 11, 2019

Report highlights:


  • In March, 2019 the National Green Tribunal issued a ban on the use of coal gasification in the ceramic units of Morbi-Wankaner area and ordered to close down all the coal gasifiers
  • The existing natural gas distribution infrastructure enabled an immediate switch to natural gas, which in turn produced dramatic environmental and air quality improvements. 
  • The region’s air quality readings saw a 75% reduction in PM2.5 levels, 72% reduction in PM10, and an 85% reduction in SO2.


  • LONDON saw a gradual improvement in its air quality, since the first introduction of its 1956 Clean Air Act
  • It introduced measures that dramatically reduced the use of coal inside homes, which was replaced largely by natural gas and electricity.
  • As a result, SO2 concentrations generated from household dropped from more than 400 µg/mto less than 50 µg/m3.
  • Most recently, the introduction of the Carbon Price Support program caused coal power generation to drop by 73% between 2013 and 2017, with the associated benefits in the reduction of air pollutants.


  • BOGOTA has been on an overall positive trend in management of its air pollution, showing up in reduced levels of PM10 and PM2.5 in recent years.
  • One large contributor to the improvement has been the city’s bus rapid transport system (BRT) helped resolve the growing issues of traffic congestions resulting in drops of both emissions and air pollution
  • At present, the city of Bogotá and Transmilenio are taking further action to reduce city pollution and renewing 70% of their bus fleet, with 53% of the new vehicles to be fueled by compressed natural gas (CNG).

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