Fighting air pollution is not only good for our lungs, but also good for the health of Arizona's economy. Reduced idling, increased testing are key.

Volkswagen will have to stand trial in Arizona over the sale of diesel vehicles that were sold to state residents as emitting less pollution. In an order made public Wednesday, Maricopa County ...

It’s a crisp winter morning in Phoenix. The sky is clear, the sun is shining and it finally is below 100 degrees. As you walk, a pickup truck sits idling at the curb, its tailpipe coughing a thick ...