It's Not As Hot, So Why Is Houston Under Ozone Watch?

An ozone watch is in effect in Harris County today. People with respiratory problems — children and the elderly should limit their time outside.

The ozone season in the Houston area runs from March 1st to November 1st.

Dr. Latrice Babin is the environmental toxicologist with Harris County's Pollution Control department. She says the public often associates high ozone with heat, but the temperature doesn't have much to do with it.

"It's not really a factor of how hot it is, it's the presence of the sunlight and the lack of wind to move and circulate and move those emissions around. So when they're stagnant and not a lot of movement, then you have the probability of having an ozone issue."

Conditions are just right for elevated ozone levels, although rain in the forecast could help clear out the pollutants later this week.

In the meantime, Dr. Babin says although the cooler weather is tempting, it's not the best time to be outside.

"Those that are considered most at risk are the young and the elderly. Also those that have respiratory issues like asthma, bronchitis, those that may have pneumonia, those folks are immuno-compromised and so their lungs get taxed when it's high ozone exceedance days."

Babin says if ozone levels get high enough, even healthy adults may experience tightness in the chest or difficulty breathing.
The Texas Commission on Environmental Quality reports there have been 30 days this year with Level Orange Ozone in the Houston area. That's compared to 36 days last year during the same time period.

Bio photo of Laurie Johnson

Laurie Johnson

Local Host, All Things Considered

Laurie Johnson is the Houston host for All Things Considered at KUHF NPR for Houston. Before taking the anchor chair, she worked as a general assignments reporter at KUHF, starting there as an intern in 2002...