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Ozone

Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth's upper atmosphere and at ground level. Ozone can be good or bad, depending on where it is found:

• Good Ozone. Ozone occurs naturally in the Earth's upper atmosphere-6 to 30 miles above the Earth's surface-where it forms a protective layer that shields us from the sun's harmful ultraviolet rays. This beneficial ozone is gradually being destroyed by manmade chemicals. An area where the protective "ozone layer" has been significantly depleted-for example, over the North or South pole-is sometimes called "the ozone hole."

• Bad Ozone. In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone at ground level is a harmful air pollutant.

The Ozone considered for discussion in this website is Ground Level Ozone. For additional information about Good Ozone, you may wish to search “ozone depletion” on the internet or see the EPA's website.

Good Up High, Bad Nearby

Chief Causes for Concern

What is it? Where does it come from?

Health and Environmental Impacts

Sources of Air Pollution

• State
• North Central Texas Council of Governments

What is the DFW Region’s Air Quality Problem?

TECQ - State Implementation Plan (SIP)

North Central Texas Council of Government - DFW State Implementation Plan (SIP)

Air Quality Color Heatlh Guide

Air Quality Index (AQI) and Health Guide

Air Pollution Watch & Warning

Subscribe to Air Pollution Notifications

Do Your Share

• Citizens
• Employers
• Organizations

Ozone Tips

City of Dallas Ozone Plan Update (Adobe pdf)