Once known as the Smog Capital of the World, Los Angeles has changed "air you can see " into "air you can breathe ." While the fight to eliminate pollution in the city continues, modern smog is not the thick, oppressive, silver-blue haze that drove people to move out of Los Angeles altogether during the mid-twentieth century. Professor Arie Haagen-Smit became a key leader in the fight against smog after making a crucial discovery—what caused it.

Join author Carl R. Oliver as he delves into the sixty-year battle to clear the air in Los Angeles.