Tracking dirty air in Texas' largest city

EDF is expanding its air quality mapping program to Houston

After EDF and our partners could see just how much air pollution varied within city blocks in Oakland, EDF decided to take our project to a new location—one that is much larger, with a more diverse mix of pollutants and a well-known comingling of commercial and industrial activity with residential areas: Houston.

Once considered the nation's smog capital, Houston has significantly reduced air pollution over the past two decades. But the eight-county region’s air quality still does not meet health-based federal standards for ground-level ozone, or smog.

Google Street View car in Texas

For this project, two Google Street View cars drove around neighborhoods in Houston equipped with air monitoring equipment.

Ozone is a persistent problem for Houston because of the region’s dense network of petrochemical facilities, busy ship channel, sprawling highways, car-dependent culture and climate. On many days, its air also contains vehicle exhaust and harmful pollution from oil refining and petrochemical facilities – all common in Houston.

The people living along the heavily industrial Houston Ship Channel face higher exposure to air pollution than the region at large. Even then, smog knows no boundaries. Some of the worst places for ozone in the Houston area are in leafy suburbs miles away from the Ship Channel.

New city, new methods, new pollutants and new questions

For this project, EDF partnered with researchers from Rice University, Google Earth Outreach and Sonoma Technology, and drove two Google Street View cars outfitted with a suite of air monitoring equipment in neighborhoods across Houston from July 2017 through March 2018. We drove the cars from early in the morning until late at night during the work week and on weekends, down every street in the selected areas to create detailed pictures of air pollution patterns across the city.

We chose neighborhoods based on their proximity to facilities that are common sources of resident complaints, areas with higher prevalence of asthma, as well as parts of towns with high truck traffic. The cars drove census tracts that are both socioeconomically and racially diverse, which should help researchers better understand the link between air pollution, race or ethnicity, income status and health in Houston.

Our scientists are now busy analyzing the more than 53.7 million valid data points and are already honing in on some key questions that driving in Houston has raised, including:

  • How does weather impact measurement? Unlike Oakland, which has relatively stable weather patterns, Houston experiences excessive heat, massive downpours and frontal systems that can roll in quickly.
  • How can we use air quality measurements taken at road level to better understand emissions from cars and trucks?
  • Do the lessons we learned in Oakland hold true for a city that's completely different? Are we seeing hot spots in the same way?

We're also working closely with other members of Houston's One Breath Partnership, so once we have results in hand, we can help equip community members with new evidence that will help them as they advocate for improved air quality.