California’s polluted places: What has a landmark state law done to fix dirty air?

THE SOUTH STOCKTON classroom where Ashley Pearl Pana spent recess trapped indoors is still there, 16 years later. 

When the wind stirred up dust and soot, when the sun stewed smokestack and tailpipe exhaust into smog, when pollution squeezed her airways, Pana’s asthma forced her inside, behind the classroom’s closed door.