But what is smog? What were the pieces that made up this chemical puzzle? And how did Los Angeles free itself from this toxic nuisance and bring back “sunny California”? The term “smog” is a ...

When the smog finally lifted ... and ammonia comes from fertilizer use and automobiles. Again, the right chemical processes have to interplay for the deadly haze to occur in China.

It's a method that's largely unproven, but Thailand's government is willing to try anything after air pollution in the ...

Residents and visitors are on alert after Hawaii's Kīlauea volcano entered its fifth eruptive episode since December on Wednesday.