Air Quality in Megacities Around the World
An overview of the air quality issues, trends, current initiatives, and potential path forward for improving air quality in five current or potential megacities around the world: São Paulo, Brazil; Cairo, Egypt; Tehran, Iran; Delhi, India; and Beijing, China.
by Prakash Doraiswamy, Golam Sarwar, and Ali Farnoud
Megacities typically refer to urban agglomerations with a population of more than 10 million people. The world's population was estimated to be around 7.3 billion in 2015 and is growing at a nearly linear rate of approximately 80 million people per year. Likewise, around 36 urban agglomerations are projected to exceed 10 million in population by 2020, meeting the definition of a megacity.
Rapid urbanization is accompanied by challenges in transportation, energy demand, and industrialization that lead to a concomitant rise in air pollution in the absence of proper planning.
In this issue, we have five articles presenting the air pollution challenges faced in five current or potential megacities around the world: São Paulo, Brazil; Cairo, Egypt; Tehran, Iran; Delhi, India; and Beijing, China.