Clean air is critical to our health, economy, and quality of life. By failing to meet the federal standards for clean air, our regional economy could lose millions of dollars each year, and your health is at serious risk.
AirNow Interactive Map of Air Quality
What is ozone?
You can’t see it or smell it. Ozone is formed through chemical variations between natural and man-made emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs). Sunlight is also needed to form ozone.
Stratospheric Ozone ("good ozone")
Stratospheric ozone forms high in the atmosphere when intense sunlight causes oxygen molecules (O2) to break up and re-form as ozone molecules (O3). These ozone molecules form the ozone layer and are commonly referred to as "good ozone."
Ground-Level Ozone ("bad ozone")
Ground-level ozone forms just above the earth’s surface and impacts human, plant, and animal respiration. Ground-level ozone is an irritant and is bad for your health. Arizona’s weather plays a big role in forming ground-level ozone.