I grew up in LA (although I live in San Diego now), and all of these answers are correct. LA actually has much better air than when I lived there and the effects of smog on your body are relatively small if you follow the following: 1) Don't live inland (especially East of Downtown), 2) Try to live within 5 miles of the coast or somewhere that's got good wind circulation and is not "backed up" against the mountains (these are the worse areas), 3) Remember than falls/winters/springs have almost no air problems. It is summer (like now) when these issues can pop up. Here's some communities that would fit the bill: Marina Del Rey, Santa Monica, Westchester, Mar Vista, Brentwood, Redondo Beach, Hermosa Beach, Playa Del Rey, Venice, Torrance, Palos Verdes, Manhatten Beach...BUT thesee are going to be a bit more expensive than their "inland" counterparts. Hope this helps!