I have not been to LA for a while, but I can tell you that the air is considerably cleaner in recent years than it was in the 1970s. More people, more cars and the air is cleaner. I believe there is less real industry and the cars are cleaner. The Bay Area never has had a smog problem as they export theirs to the central valley (yes, this is true). The natural breezes blow the Bay Area smog over the Altamont pass and down the valley where it settles in Bakersfield...