Fires and agricultural soils can rival cars and factories in emitting chemicals that lead to ozone, making it hard to meet air quality standards.

The Phoenix area's long-standing ozone pollution issues could have serious impacts on local economic competitiveness and ...

The Valley has seen decades of big business deals and population growth. A yearslong fight over air pollution could now endanger its future.

The EPA says Phoenix-area air quality has worsened to “serious” levels, a designation that would trigger growth restrictions, ...

a different type of air pollution. On Wednesday, he publicly asked Kelly to send over a catalog of requests for his agency — a list that is almost certain to include pausing the ozone ...