Kenneth Encarnacion: This is Kenneth Encarnacion with 91.9 KVCR.
Rick Flagan: We did have the X-Ray fluorescence data which allowed us to trace the heavy metals. The one that caught everyone’s attention… was lead.
Kenneth Encarnacion: January 2025. Wildfires have ravaged the greater LA area, burning over 40,000 acres and more than 12,000 structures. The Eaton fire alone, consumed over 14,000 acres in suburban Altadena coming uncomfortably close to the California Institute of Technology or Caltech.
However, the fire’s damage might go deeper than what we can see. Invisible yet toxic materials in the air can do serious damage to our health and the health of our loved ones. I sat down with a well-recognized voice in air quality research to discuss the invisible effects of the fires, the history of this research, and the role the Inland Empire plays in all of this.
Rick Flagan: My name is Rick Flagan. I’m a professor of chemical engineering and environmental science and engineering at the California Institute of Technology, Caltech. Been involved in this study of particles in the air, what we call aerosols, and in particular looking at those related to air pollution.
Thing that really got us going on the fires is that a former student here whose now on the faculty at Georgia Tech, Sally Ng, has led an effort to build a national network to monitor what has become the standard measurement for particulate air quality which is the so-called PM 2.5. That is a measure of particles smaller than about two and a half microns. And the two and a half microns is a size cut that was selected as representative of the particles that can penetrate deep into the lungs even when you’re at rest and breathing through your nose. If you’re breathing through your mouth, bigger particles can get down there. Under relaxed conditions that’s a reasonable upper bound for that region.
But for the chemical information, it’s all based on PM 2.5. That includes measurements of the organic and volatile species in the aerosol. In addition, there is a monitor for looking at lead and other trace metals. So with those measurements it’s providing a continuous record of the PM 2.5 in the atmosphere and with the size distribution instruments, a continuous record of the size distribution.
Due to an instrument failure, the day before the event occurred, we did not have the organics data. We did have the X-Ray fluorescence data which allowed us to trace the heavy metals. The one that caught everyone’s attention… was lead.
And that concentration jumped up to quite high levels above what we typically see these days. Although, we have seen concentrations like that before. Twenty five years ago when there was a lot of use of leaded gasoline. We were exposed to similar lead levels every day.
There are a dozen stations that have been set up under this network. There are three in Southern California. There is one at Pico Rivera, in the Los Angeles basin, there’s one in Rubidoux, and then another in Joshua tree. The lead spike that we saw was occurring at Pico Rivera. It occurred when we had the winds coming out of the north and slightly to the west and was blowing down to the coast. It did not spread directly into the Inland Empire.
Kenneth Encarnacion: A huge relief for us in the IE. I asked Dr. Flagan about how Caltech seeded air quality research in the Inland Empire, and the role UC Riverside is playing through the Center for Environmental Research and Technology, commonly known as CE-CERT
Rick Flagan: Well… this starts out with some of the key people at CE-CERT. David Cocker did his Ph.D. here, working on our chamber experiments. He moved to CE-CERT. He had learned how to build a chamber, and he built a beautiful facility there that continues to provide absolutely critical data. He and others there use some of the instruments that have come out of my laboratory. It goes beyond just this region, just Southern California, these have had effects all over the world.
Kenneth Encarnacion: There was a lot more in my discussion with Dr. Flagan, but sadly we’re out of time for now. With new topics coming out every day, like the rise of resource-hungry AI, the debate over the costs and benefits of environmental policy, the discussion around air quality is as important as ever.
With 91.9 KVCR, this is Kenneth Encarnacion.
—
As an emerging chemical engineering researcher and science communicator, Kenneth will soon begin his Ph.D. driven by a passion for learning and teaching. Kenneth seeks to be a leader in science and religious education to train up a future generation of engineers and scientists that are responsible and excellent.