Bowden collecting water samples from a stream.

Mackenzie Bowden is shining a light on water hazards in the aftermath of wildfires.

“When people think about fire, water isn’t the first thing they consider, but when you look at events like the 2021 Marshall Fire and the 2025 fires in Los Angeles, there are all these synthetic compounds that get introduced to the water supply in runoff from burned homes,” Bowden said. “We want to know what that does for people downstream who drink that water.”

Three Minute Thesis

An environmental engineering student at the University of Colorado Boulder, Bowden has already earned accolades for her work, earning second place at the campus Three Minute Thesis Competition.

The event challenges graduate students to craft a three-minute elevator pitch for their complex—and sometimes difficult to make sense of—research in a way that even an everyday person could understand. Bowden was one of 11 presenters to take part in the competition last month.

“It’s very rare to have a dedicated audience listening to you talk about your research,” she said. “You spend all your time in the lab or writing papers, talking only to the niche audience in your field. This is about seeing how well I can discuss what I’m doing with other people.”

Fire Aftermath

Bowden came to CU Boulder in the aftermath of the Marshall Fire, which destroyed over 1,000 homes. With a background in analytical chemistry, she began analyzing the complex compounds that result from fires at the wildland-urban interface.

“Risk assessment tends to look at specific chemicals in isolation, but chemicals don’t appear in isolation, they’re in mixtures. If you look for lead, that’s important, but what if the lead binds with things you aren’t looking for,” she said.

The ash and remnants of wildfires in forests and grasslands are comprised primarily of well-understood organic materials. With wildfires increasingly spreading to towns and cities, there is potential for more problematic pollution.

To effectively monitor those situations, Bowden has conducted hands-on research of the materials that comprise modern homes.

“I go buy construction materials like PVC pipes, fiberglass insulation, roofing materials, and burn them under controlled conditions so I can measure the organic and inorganic content of the ash as well as its toxicological potential,” she said.

Chemical Analysis

The analysis combines chromatography, mass spectrometry, and biological assays to identify resulting compounds, determine their quantities, and evaluate biological response.

“Samples contaminated by burnt PVC pipes were always more toxic than anything else, but when that burnt PVC was present with burnt wood, that toxicity was masked. It’s a prime example of how mixture interactions would have been completely misinterpreted by single chemical tests,” Bowden said.

Bowden will defend her dissertation next month. After graduation, she is seeking postdoctoral fellowships with an eye toward becoming a university professor.

“Environmental engineering is a very multidisciplinary field,” she said. “It pulls in environmental science, chemistry, biology, and ecology. It’s all these different puzzle pieces being fit together. I want to keep contributing and advancing the field.”

 

Bowden speaking at Three Minute Thesis