After more than 50 years of fighting with smog, Los Angeles finally has a blue sky again.
Besides of cleaning up cars, LA County has done many projects to reduce air pollution.
In 2008, two California based journalists Chip Jacobs and William J. Kelly published a book called "Smogtown: The Lung-Burning History of Pollution in Los Angeles."
Let's figure out how do they tell the story of the war against smog in Los angeles.
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