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TRAX Helps With Utah's Air Quality, This Time Through Research

Garrett via Wikimedia Commons

People know they can help clear the Salt Lake Valley’s air by hopping onto TRAX trains.

What they might not know is how an air-quality monitor mounted on the roof of a train car is also helping solve the valley’s pollution puzzle.

As it crisscrosses the valley, the car gathers data about pollution trends, sometimes on the green line route, sometimes along the red line.



New research led by a University of Utah atmospheric scientist shows how the electric-powered trains have become a useful scientific tool.

The findings, published in the journal Atmospheric Environment, suggest Utah’s experiment with the TRAX monitors might be valuable to researchers elsewhere.

With a new way to look at air quality across the train’s routes, researchers can pinpoint pollution sources and trends, said Logan Mitchell, who led the study.

“You can show it to someone and see, ‘Oh, look! That’s what’s going on right there that’s causing ozone to go down and NO2 [nitrogen dioxide] to go up and, oh, it’s because of this emissions source’,” he said.

One insight from the data is how rail yards are a surprisingly big pollution source. Also, dust storms can pose health risks to kids playing outdoors on the western side of the valley — but not on the eastern side.

Mitchell said the official pollution monitor in the Salt Lake Valley is located downtown at Hawthorne Elementary, and it takes pollution and weather measurements just at that site. But the monitor-equipped TRAX trains have been gathering lots of data across the valley for more than three years. That’s given researchers important details about the valley’s pollution patterns that they couldn’t get from the Hawthorne model.

“We’re just now understanding what are these patterns,” Mitchell said. “And it’s going to help us understand what are cost-effective measures to reduce pollution.”

State lawmakers this year pledged to fund $100,000 annually to support the TRAX train research.

Commuter Carrie Kirkpatrick said she hadn’t known about the air monitors until she was asked about them by a reporter. But she was happy to hear the issue is being studied as Salt Lake’s air quality has been on her mind since her family moved to the area last year.

Credit Judy Fahys/KUER News
Carrie Kirkpatrick said she uses transit and rides a bike to reduce her contribution to the Salt Lake Valley's poor air quality. She favors research that leads to pollution solutions.

That’s one of the reasons she rides public transportation to work, she said after boarding the TRAX red-line train at the University Medical Center on the University of Utah campus.

“More data isn’t always better,” she said. “But, hopefully, the data they’re getting will be useful and will be able to help make some changes.”

Ashley Miller, executive director of the health advocacy group Breathe Utah, hopes so too. She said the data provides a foundation to build sound policy, but more research is needed to solve a complicated problem.

“When we can identify sources, when we can identify actual pollutants in the air,” she said, “that’s what’s going to be useful for policy makers and state regulators to step in and actually do something about it.”

Judy Fahys has reported in Utah for two decades, covering politics, government and business before taking on environmental issues. She loves covering Utah, where petroleum-pipeline spills, the nation’s radioactive legacy and other types of pollution provide endless fodder for stories. Previously, she worked for the Salt Lake Tribune in Utah, and reported on the nation’s capital for States News Service and the Scripps League newspaper chain. She is a longtime member of the Society of Environmental Journalists and Investigative Reporters and Editors. She also spent an academic year as a research fellow in the Knight Science Journalism program at the Massachusetts Institute of Technology. In her spare time, she enjoys being out in the environment, especially hiking, gardening and watercolor painting.
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