With 47 100-degree days, it’s no surprise to North Texans that this year’s summer was the fourth-hottest on record.
But the region also experienced the worst air quality season since 2012, with the Texas Commission on Environmental Quality issuing 61 warnings in 2022 about potentially unsafe ozone conditions. The TCEQ counted 48 days where ozone concentrations exceeded safe ozone levels, the highest number in a decade.
“Increased heat can cause high ozone levels, considered a sign of poor air quality,” said Estella Wieser, a media relations specialist for the TCEQ.
Ozone is more readily formed during higher temperatures – on sunny, warm days when air is stagnant, according to the EPA. In the DFW area, the ozone-forecast season lasts from March 1 to Oct. 31, when the region is likely to experience higher levels of ozone, according to the TCEQ.
The TCEQ declares “ozone action days,” or a public notification to residents, when meteorologists forecast conditions that are conducive to producing higher levels of ozone that could reach the orange category, or higher, on the EPA’s air quality index scale, Wieser said.
The EPA’s air quality index scale is divided into color-coded categories. Each category is identified by a simple descriptor. The orange category is described as “unhealthy for sensitive groups.”
In 2015, the EPA strengthened the National Ambient Air Quality Standards for ground-level ozone to 70 parts per billion (ppb), revising the 2008 standard of 75 ppb.
Earlier this year, the EPA announced its intention to downgrade Dallas-Fort Worth’s air quality status and list the region as a “severe violator” of those 2008 ozone standards, which declared that cities must reduce their ozone levels to beneath 75 ppb. As of Oct. 20, ozone concentrations in North Texas averaged over 70 ppb over a period of 48 days.
EPA “severe violator” consequences
Penalties for not meeting the Clean Air Act Standards consist of revising state implementation plans and stricter pollution control, according to previous Fort Worth Report coverage. A region that is classified as a “severe violator” can impose $5,000 per ton penalties on major sources if the area does not meet required reductions.
With the exception of 2019, 2020 and the current data from 2022, the number of days that ozone levels exceeded healthy air quality standards outnumbered the number of ozone warnings issued by the TCEQ.
That discrepancy could be caused by real world conditions, such as wind speed and direction, rain, temperature, clouds, and emissions that measure differently than the forecast, which could cause an ozone exceedance day to occur when it was not previously expected, Wieser said.
Ground-level ozone forms when emissions from transportation, industrial and commercial operations, and natural sources such as vegetation emit nitrogen oxides and/or volatile organic compounds. These pollutants react in the presence of sunlight and heat to create ozone, according to The North Central Texas Council of Governments.
About 67% of nitrogen oxide emissions in North Texas come from transportation with 38% of that stemming from on-road mobile vehicles such as cars and trucks, according to 2020 data collected by the council of governments.
“Our main focus is continuing to reduce the emissions from transportation, which is all the trucks in the cars that are driving around in the region on a regular basis,” said Chris Klaus, senior program manager at the council of governments. “Internal combustion engines predominantly generate a lot of the nitrogen oxides – if you can reduce all the man-made nitrogen oxide emissions, then that should lower the ability to form ozone.”
Industrial emissions are also a large source of emissions, said Jim Schermbeck, director of Downwinders At Risk, an environmental activism group based in Dallas. All of the blame for higher ozone levels is being placed on cars when the state should take action on other emission sources as well, he said.
This year’s hot summer weather and increasing levels of ground level-ozone are cause for concern, Schermbeck added.
“It’s a nightmare scenario statistically,” he said. “When you have higher ozone levels, you increase hospital admissions, you increase doctor visits, you increase asthma attacks, you increase heart attacks and strokes. There’s all kinds of damage done.”
Izzy Acheson is a reporting fellow for the Fort Worth Report. Contact her at firstname.lastname@example.org. At the Fort Worth Report, news decisions are made independently of our board members and financial supporters. Read more about our editorial independence policy here.