Air Quality Control - Ozone Explained

What is Ozone?

Ozone is a gas that is formed in the atmosphere when three atoms of oxygen combine. Naturally occurring ozone is found high in the stratosphere surrounding the earth and in ground-level ambient air.

How does it occur?

Ozone pollution is a key component of smog. It is mainly a daytime problem during the summer months. Strong sunlight and hot weather causes ground level ozone to form in harmful concentrations in the air. Ozone is formed as a consequence of chemical reactions in the atmosphere where the reactants are nitrogen oxides and volatile organic compounds in the presence of light.

Ozone is not emitted directly into the air. Instead it is formed in sunlight, which initiates a series of complex atmospheric chemical reactions. These reactions primarily involve nitrogen oxide (NOx) and volatile organic compound (VOC) emissions, called precursors.

At ground level, ozone can harm plants and other materials through a process called oxidation. For these reasons, ozone is called a photochemical oxidant.

The concentration of ozone in the air is determined not only by the amounts of ozone precursor chemicals, but also by weather and climate factors. Intense sunlight, warm temperatures, stagnant high-pressure weather systems, and low wind speeds cause ozone to accumulate in harmful amounts.

Effects of high concentrations of ozone and who will suffer

(EFFECTS) Shortness of breath, coughing or wheezing, headaches, nausea, throat and lung irritation.

(WHO) Children, people with lung disease, and active adults Click to learn more

Click on the links below to see current ozone levels in the Houston Area. There is also a link to sign up for notifications when ozone levels in our area are high.