Professor Victoria “Tori” Barber is part of a multidisciplinary team at UCLA who are working with the L.A. County Fire Department to isolate the contaminants on the clothing of firefighters and assessing their effects on human cells. The study will help determine if personal protective equipment (PPE) contributes to firefighters’ cancer risk.
Barber joined the UCLA faculty as Assistant Professor of chemistry and biochemistry in July 2023. She conducted her undergraduate studies at Swarthmore College, where she majored in chemistry, with a minor in educational studies. Barber worked for a short time in the emission controls industry as a process development technician, before returning to school to complete her Ph.D. at the University of Pennsylvania, where she was the Miller fellow in physical chemistry. There, she worked with Professor Marsha Lester, using laser spectroscopy to study the chemistry of atmospheric reactive intermediates. After completing her Ph.D., Barber moved to MIT, where she joined the Department of Civil and Environmental Engineering as a postdoctoral researcher. There, she broadened her focus toward a more applied understanding of organic chemistry in the Earth’s atmosphere.
At UCLA, Barber’s team employs various techniques in physical and atmospheric chemistry to understand the physical and chemical processes that govern the evolution of organic molecules in air. Their work enables improved predictions of atmospheric composition, climate, and indoor and outdoor air quality.
From UCLA Newsroom (by Mary-Rose Abraham):
UCLA researchers team up with L.A. County Fire Department to investigate possible source of cancer risk
Key takeaways
- In cooperation with the Los Angeles County Fire Department, a multidisciplinary team at UCLA will isolate the contaminants on firefighter jackets and assess their effects on human cells.
- Firefighters at one station will wear the jackets in rotation for two months, then send them back to researchers, unwashed and coated with debris from their firefights.
- Once the chemists isolate the gases and PM from the jackets, Gomperts will test their effects on human cells.
Every night around 8, the air quality sensor inside Los Angeles County Fire Station 3 registered an alarming spike.
The late evening timing provided a major clue: firefighters were craving their after-dinner snack of popcorn. Popcorn burning on the stove would trigger the air quality monitor. Cooking can release harmful gases, particles and chemicals, a major source of indoor air pollution.
Firefighters are already exposed to smoke and other toxins during a firefight. They may inhale, ingest or touch known and suspected carcinogens such as benzene, phenols and heavy metals. The effects on their health include a 9% higher risk of a cancer diagnosis and a 14% higher risk of dying from cancer compared with the general population.
But less is known about the hazards inside the fire station. Cooking is likely not the only one. Fire trucks emit diesel fumes. At Fire Station 3, traffic exhaust can seep in from two overhead freeways.
It was the station’s captain, Jeffrey Kimura of LACoFD, who directed researchers’ attention to another possible source: turnout gear, the personal protective equipment that keeps them safe on the job.
The heavy-duty jackets and pants must be washed in specialty machines that are typically off-site, so they are worn multiple times before laundering. The dirt and debris from firefights accumulate on the clothing. The gear is stored in the station between calls, adjacent to living quarters, and may be a significant source of toxicity.
In cooperation with LACoFD, a multidisciplinary team at UCLA, led by Dr. Brigitte Gomperts and Kimura, will isolate the contaminants on the clothing and assess their effects on human cells. The study will help determine if PPE contributes to firefighters’ cancer risk.
The concept is similar to thirdhand smoke, the residue that settles on surfaces after a cigarette is extinguished, continuing the exposure to hazardous chemicals.
“Nobody’s ever tracked firefighter gear serially over the course of a year,” said Gomperts, associate director of translational research at the UCLA Broad Stem Cell Research Center and co-director of cancer stem cell biology at the UCLA Health Jonsson Comprehensive Cancer Center.
“We hypothesize that PPE carcinogens will induce changes in cells that are probably not good for cell health, and this could influence cancer risk in firefighters.”
The group is one of eight across the University of California awarded state funding from the California Firefighter Cancer Prevention and Research Program.
Extracting chemicals
The UCLA team will purchase five new firefighter jackets. Before sending them out to the station, they will perform baseline testing. The material of the PPE may itself be carcinogenic. Its textiles contain PFAS, known as “forever chemicals,” which are linked to cancer.
Firefighters at Station 3 will wear the jackets in rotation for two months, then send them back to researchers, unwashed and coated with debris from their firefights.
“Materials and surfaces act like sponges for chemicals that slowly get re-released into the air, and we think the same is going to be true for PPE,” said Dr. Victoria Barber, an assistant professor in the department of chemistry and biochemistry who studies indoor air. “There’s a potential that things are evaporating from that gear over long timescales and resulting in exposures for the firefighters.”
Barber will use a technique called “off-gassing” to analyze what’s on the jackets. A sealed, heated container encourages evaporation. She will then use a mass spectrometer to determine the composition and concentration of what’s in the air.
Barber theorized what she might find on the jackets: most likely semi-volatile organic compounds that deposit on surfaces and are also found in fire retardants. She believed that off-gassing could also reveal volatile organic compounds, including the highly toxic BTEX (benzene, toluene, ethyl, xylene) compounds formed in fires.
But gases are not the only contaminants likely to be found on the jackets. Particulate matter (PM) refers to mixtures of solids and liquids made up of hundreds of different chemicals. They are large enough to be seen (smoke, soot) or tiny (30 times smaller than a human hair). When the microscopic PM is inhaled, it can lodge deep in the lungs and cause serious health problems.
The research team includes Dr. David Gonzalez, an atmospheric chemist and postdoctoral fellow with expertise in particulate matter. He has studied what happens post-inhalation, including how PM generates free radicals — unstable, chemically reactive molecules — in the lung and lung fluid, leading to toxicity.
“Particulates can settle and get stuck onto PPE,” said Gonzalez. “It’s not necessarily just inhalation that leads to exposure. Dermal exposure — if any of this is touching their skin, or maybe they’re touching their eyes, their mouth — can deliver a variety of carcinogenic compounds.”
Effects on human cells
Once the chemists isolate the gases and PM from the jackets, Gomperts will test their effects on human cells. This is done in her laboratory where mini airway systems — replicas of human lungs — nestle in Petri dishes. These three-dimensional organoids are grown from human stem cells and mimic the architecture of human lungs down to its different cell types. They include the tiny, hair-like cilia that line the airways of the lungs and beat to draw mucus, debris and pathogens out of the respiratory system.
The solids and liquids isolated from the jackets can be applied directly to the cells. But it will take a bit of engineering to expose the gases. Barber will place the jackets in an incubator, heat them up and use a pump to draw that air over the mini lungs. It’s “a pretty good proxy for what inhalation looks like,” she said.
“We think it’s a really novel approach,” Barber said. “As far as we know, it’s never been done before.”
Gomperts will then examine the cells for any changes that may reflect a reaction to toxicity: “Do they divide more? Do they die more? Do they make more mucus? Do the cilia beat or not beat?”
The final step of the study is to examine what changes inside the organoid cells at a molecular level.
Dr. Mehdi Bouhaddou uses mass spectrometry-based phosphoproteomics to study phosphorylation, a small chemical modification that gets added to proteins. This can alter how proteins communicate with each other and could result in dysregulation of biochemical signaling pathways, which is tied to the development of cancer.
Penny Jennings, UCLA Department of Chemistry & Biochemistry, penjen@g.ucla.edu.
