https://www.newsweek.com/millions-california-warned-exercising-outdoors-2005086
Of course any big city or industrial area can still get occasionally smoggy.
The LA City Hall was once the tallest building in California, now it's just like another stump building.
https://www.newsweek.com/millions-california-warned-exercising-outdoors-2005086#slideshow/2550275
