Here's an incentive for you: Look up into the brown clouds and take a DEEP, DEEP BREATH.....
Actually, when I was in the Marines in 1984 I went to a Raging Waters water park which was set into a little valley somewhere in SoCal. The "smog" had settled into the park and the act of MERELY taking a deep breath caused me to cough. It was awful, and my first indication that "smog is bad bad bad news."