big yikes

Houston lands on the wrong end of national pollution report

Houston ranks as the 15th most polluted city in the U.S. No other Texas city appears in the ranking. Photo via Getty Images

Houston just made a list that no one wants it to be on.

Data compiled by the National Public Utilities Council ranks Houston as the 15th most polluted city in the U.S. No other Texas city appears in the ranking. Three California cities — Bakersfield, Visalia, and Fresno — took the top three spots.

The ranking considers a city’s average volume of fine particulate matter in the air per year. Fine particulate matter (formally known as PM2.5) includes soot, soil dust, and sulphates.

The council based its ranking on the average annual concentration of PM2.5 as measured in micrograms per cubic meter of air, known as µg/m3. The ranking lists Houston’s average annual µg/m3 as 11.4. The World Health Organization (WHO) recommends a top µg/m3 of 5, while the American Lung Association sets 9 µg/m as an average annual guideline.

A report released in 2024 by Smart Survey found that the Houston area had just 38 days of good air quality the previous year.

“Most of Houston’s air pollution comes from industrial sources and diesel engines, although sources as diverse as school buses and meat cooking also contribute to … the problem,” the nonprofit Air Alliance Houston says.

The U.S. Environmental Protection Agency says PM2.5 poses “the greatest risk to health” of any particulate matter. Among other health issues, fine particulate matter contributes to cardiovascular disease, lung cancer, and chronic pulmonary disease.

Among the sources of PM2.5 are wildfires, wood-burning stoves, and coal-fired plants, according to the American Lung Association.

The WHO says air pollution causes 7 million deaths annually and may cost the global economy $18 trillion to 25 trillion by 2060. With 70 percent of the population expected to live in urban centers by mid-century, cities are at the forefront of efforts to reduce pollution, according to National Public Utilities Council.

Trending News

A View From HETI

A rendering of a Quaise Energy geothermal plant. Rendering via quaise.com

Houston-based Quaise Energy, a producer of utility-scale geothermal power, raised $134 million in a Series B round to advance its “superhot” geothermal power plant.

Climate-focused San Francisco-based investment firm Prelude Ventures led the round, with participation from JERA Co., Japan’s largest power generation company, and Idemitsu Kosan, one of Japan’s largest energy companies. Nearly all existing investors, including cleantech-focused investment firm Safar Partners, participated in the round.

“We have backed Quaise since the beginning because we believed accessing superhot rock would unlock geothermal energy at a scale the world has never seen,” Mark Cupta, managing director at Prelude Ventures, said in a press release.

The startup expects more equity and debt deals to close “imminently.” Quaise has raised $230 million since its founding in 2018.

Quaise says some of the fresh funding will go toward building the world’s first commercial-scale “superhot” geothermal power plant —Project Obsidian in central Oregon. In addition, Quaise is earmarking money for continued development and commercialization of its millimeter-wave drilling system toward depths exceeding 5 kilometers (about 16,400 feet).

Quaise uses a millimeter-wave drilling system developed at the Massachusetts Institute of Technology to remove rock at depths and temperatures that aren’t economically feasible with conventional drilling. With this technology, Quaise can reach rock at temperatures of around 570 degrees to 930 degrees in most places worldwide, enabling construction of geothermal systems that rival fossil fuels and nuclear energy in power density and that rival renewables in cost.

“Our ambition is to power civilization with Earth's most compelling energy source. This round takes us from field-proven technology to first commercial revenues,” Carlos Araque, co-founder, president and CEO of Quaise, added in the release.

Quaise has demonstrated the capability of its millimeter-wave drilling system at its Central Texas test site, drilling more than about 330 feet through granite in 2025—the first time the technology penetrated basement rock at full scale in the field. The company is approaching a depth of about 3,300 feet at the same site.

Construction of Project Obsidian is underway at Oregon’s Deschutes National Forest. The project, which has the potential to generate gigawatt-scale power, is slated to deliver electricity to the Pacific Northwest grid by 2030.

Trending News