Energy and Environment Reporting for Texas

Houston’s Ozone Mystery: Pockets of Pollution Unlike Other Cities

Air pollution monitoring station at Croix Memorial Park in Manvel

Dave Fehling / StateImpact

Air pollution monitoring station at Croix Memorial Park in Manvel

At the Texas Commission on Environmental Quality (TCEQ), they’re very familiar with a park in Manvel, a small town 15 miles south of downtown Houston. It’s a place where prairie land is quickly being turned into subdivisions but it still retains a rural appearance.

In Croix Memorial Park, between a soccer field and a playground, is one of the TCEQ’s air pollution monitoring stations, one of over 20 spread across the Houston area.

For some reason, the monitor in Manvel shows that ozone levels here are among the worst in the metro area. Consistently. And they haven’t come down as they have over the past decade at other monitoring sites, some of them near areas with far more sources of pollution from vehicles or industries.

“So the question is why, what’s different about that site,” said David Brymer, director of air quality at the TCEQ. “It’s south of town. Houston’s not really known for consistent north winds that would blow the urban core emissions towards that monitor. “

Brymer told StateImpact one explanation could be the weather: heat, humidity, wind. All could be factors. But the more that scientists study ozone, the more it seems they find there are no easy explanations.

Houston Does Ozone Differently

They’re learning that Houston stands out as unique in the United States when it comes to ozone. The metropolis is one of the most ozone-monitored regions in the country and does not meet federal clean air standards.

“There’s been so much focus on Houston for more than a decade,” said Anne Thompson, a research scientist with NASA’s Good Space Flight Center in Maryland.

“Houston is unique. Why it gets studied is you have a very concentrated petrochemical industry and of course, you have your tropical meteorology that kind of mixes up the hot, sunny conditions. So that’s unique,” said Thompson.

Thompson is working on NASA’s DISCOVER-AQ Mission. It’s goal is to find a way to use satellites to track air pollution. In Houston, satellite images might unravel the ozone mystery by tracing its sources.

“We find the ozone pollution in Houston is quite variable. So depending on what side of town versus the other, you can have very polluted conditions on one side of town and be perfectly clean on the other side of town,” said Jim Crawford,  NASA’s principal investigator for the DISCOVER-AQ Mission.

“Whereas on the East Coast and in California, you’ll often find a metropolitan area’s ozone goes up and down in concert. So you’ll have the whole area be polluted or the whole area be very clean but rarely have pockets of pollution like you find in Houston.”

Are the Pollution Monitors Broken?

Scientists working on NASA’s satellite project met last week at Rice University to update each other on data gathered for air pollution research. Among the presentations, one raised the role played by “background ozone” which is naturally occurring or originates elsewhere from Mexico or other countries but drifts into Houston. Knowing the background level is important because it’s considered by the EPA when setting clean air targets for cities.

Another presentation by an engineer with the American Petroleum Institute, Cathe Kalisz,  raised the possibility that the existing method for measuring ozone —- all those air monitors like in the park in Manvel — might be inaccurate. Kalisz said improved monitors are being tested in Houston.

Could that be an explanation for the consistently high ozone readings in Manvel: a faulty monitoring station?

“Anything’s possible,” said the TCEQ’s Brymer. But he told StateImpact that the Comssion has “really stringent quality assurance” for its monitoring equipment and what’s at Manvel is no different than those used at other sites.


  • jhvtex

    Gee, given that the prevailing wind in Manvel comes from the SSE almost all year (except a few days between October and April when ephemeral northers shift it 180 degrees for a short while), it couldn’t be due to the presence of atmospheric emissions from the Monsanto and Amoco chemical plants located ~20 miles SSE of the town, now could it?

  • “anything’s possible”… does that include going and replacing the sensor? Geez this is ridiculous

  • texasistoxic

    Thanks for the article. Unfortunately, the scientists apparently have forgotten the obvious … OK, API, NASA have vested interests in obfuscation, one for confusion and denial, the other to fund a space program rather than solve the problem.

    Ozone is simple: Volatile Organic Compounds (VOCs) plus Nitrogen Oxides (NOx) landing on a surface, such as a Particulate (PM2.5s) with Ultraviolet makes Ozone. In Houston those come from different sources and combine far from the source downwind to make ozone.

    The readings from the monitors are real. The damage to the health of Houston has been proven and is apparent in the direct relationship between the 90% fatal out of care heart attacks, and the distribution of ozone and PM2.5s that are mapped with each other across Houston.

    “blow the urban core emissions” to Manvel is complete deception, and is a surprise to hear from TCEQ. OK, maybe not a surprise. Rather look to the emissions from the industrial point sources, the ship channel, Texas City, Sweeney, off shore rigs, Mt. Bellview, etc.

    Given the minute, or five minute data from each of those monitors high school juniors could chart the source of the individual components. Chart the components, VOCs, PM2.5, NOx are all poisonous. PM2.5s are called “invisible killers” for a reason.

    Some individuals, high school juniors, were sensitive enough to smell the onslaught of the front end of an ozone plume, cloud, and miasma. More children show the effects of breathing ozone with poor behavior, and performance in testing.

    Yes, ozone is formed downwind of those sources. The major sources of those VOCs, NOx, and PM2.5s are the industrial point sources.

    Industry always wants to point somewhere other than their own stacks and processing facilities. API members don’t publish actual emissions, so all of their comments are without merit. The API has never addressed the fact they have never reported actual emissions rather they use emission factors that have been shown to be 2 to 250 times too low. The most toxic carcinogenic emitting units, cokers, don’t even have emission factors–missing all those VOCs in the emission inventory is not an accident, it was hard lobbying by the API. The API would have backyard grills and lawn mowers legislated rather than their refineries.

    So the TCEQ gathers the emission data, but the data from the industrial point sources are misleading and outright fallacious.

    NASA might want to get the funding, don’t waste the money on them–they obviously didn’t read the 20 years of testing preceding. The Houston emissions are better monitored with LIDAR and DIAL sighting on the stacks, tanks, vents, and processing units of the industrial point sources that are emitting toxic, hazardous and poisonous elements and compounds rather than gross measures. Right very different than LA, because there isn’t a larger concentration of refining and petrochemical plants in the world, so make no comparison.

    Until industrial point sources are held accountable with board members, corporate management, supervisors directly breathing their emissions, they will be killing some and otherwise shortening lives by 12 year of all those downwind. Those downwinders include those in Conroe, Katy, Kingwood, Sugarland, Galveston — the ozone generated by the industrial point sources in the Gulf, on the Ship Channel, in Texas City, etc., travels with the diurnal winds and might get as far as Dallas.

    Best be advised to live, work out of the downwind path of PM2.5s, and Ozone.


    • sam

      I knew it!!! I saw the smog and asked can smog be here one day and gone the next? I live in conroe. I got very very sick with fibrimialgia. Almost wanted to off myself. I stoped eating processed food, and felt heald. So I knew it was chemicals in the food, and chemicals in the air because I still get sickish when there is smog. Everyone ses to agree we all feel bad on same days together as a town. It hasn’t stoped raining because tge earth is desperately trying to heal, but at some point it won’t be able to. This us reduculous tgat people would disrisrespect the earth that sgelters us and heals us. This is why we are sick or we know someone who is. Time to stand up. Each one of us together can make a difference. I’m on my journey to help and make a difference. When I went on a vowe to not eat processed foods I was shocked to find there was no such thing. Even organic read organic* like they can lie to us put what ever tgey please into our bodies as long as they put a * at the end. We don’t even have tge right to say we don’t want chemicals in our body. In our air. Just so the fat cat gets fater. And we all get sick and tgey push the world to the end. Lets stand up for our land and fight the good fight. Not the one for distruction but the one for peace on earth. And the healing powers of mother nature. They way God designed it for us. No process food!

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