Since 2017, the UC Davis Environmental Health Sciences Center has been researching the impact of wildfires on communities across the state. Dr. Keith Bein developed a Rapid Response Mobile Research Unit for analyzing components of wildfire smoke and their potential effects on health.
JB: What are you doing to build on the wildfire research you’ve done over the past few years?
Dr. Bein: We have funding from the UC Davis Environmental Health Sciences Center and the Western Center for Agricultural Health and Safety to finally look at both chemical composition as well as toxicity of all of these PM (particulate matter) wildfire samples I’ve been collecting over the years. I have a big archive now. We’ll be looking for associations between emissions, chemicals and the biological response, trying to pick out specific compounds or group of compounds that are more or less bioactive than others.
At the same time, we’ll be looking at differences between fires at the wildland-urban interface that have consumed large parts of the built environment or structures and fairly remote wildland fires—your typical forest fires. We’ll be looking at the correlation with the composition of a toxicity and the differential between types of wildfires, then compare to other well-known sources of emissions like vehicles or agriculture. We’ll get a differential toxicity and compositional profile of all these different samples so that we have systems in place to protect people.
JB: Who are you collaborating with?
Dr. Bein: I’m working with Tom Young. Tom is in Civil and Environmental Engineering and he’ll be doing all the chemistry for me. He does high-resolution mass spectrometry, both liquid and gas chromatography. So, rather than analyze the samples looking for very specific compounds we think we should look for, we go in and just show everything that's there. Whether or not we know what it is, we can see that it's a feature and that maybe that feature is causing the toxicological problems. That gives us the impetus to go in and find out what that particular feature and may be, what that particular compound really is. We can do more targeted toxicological studies and maybe understand where it's coming from, what things are combusting that are producing this particular compound.
On the toxicological side, I have a Cristoph Vogel, who is at the Center for Health and Environment and in Environmental Toxicology. He specializes in in doing toxicity testing on cell cultures. He’ll introduce the pollutant into a cell culture and watch how cells react, which gives clues about different types of inflammation or oxidative stress or cell death and what's happening in human biology.
It's big study with a lot of data and statistical analysis to try to pinpoint what the chemical compounds of most concern are in these wildfire emissions. Our hope is to develop targeted ways to try to reduce exposure or protect ourselves from particular compounds.
JB: You’re casting the net wide then narrowing down because there's an unknown quantity of potential toxicants in the air with these urban wildfires. Were you able to start with a more refined list based on your previous research or do you have to start fresh with each wildfire?
Dr. Bein: We know the typical suspects of concern when it comes to combustion in general. Like polycyclic aromatic hydrocarbons (PAHS), which have dioxin-like effects in human biology. Toxic metals that come from combusting paint, melting metal or other things that have metal additives. Halogen containing bromated or chlorinated compounds are very concerning. We have a list of things.
We have a web of knowledge to catch these unknowns. We’ll do targeted analysis. We’ll look for things we already know about. But we’ll also look for things we’ve never seen before and there will be a lot of them. Hopefully we have enough knowledge already that we can catch these new things and put them in their correct groups and identify what they are.
"We have a web of knowledge to catch these unknowns. We’ll do targeted analysis. We’ll look for things we already know about. But we’ll also look for things we’ve never seen before and there will be a lot of them."
JB: Explain the process in a little more detail when you come across a chemical compound you haven’t seen before. How do you separate out the threads to figure out what things have come together to create that new molecule?
Dr. Bein: We use mass spectrometry. This has been around for decades and decades, so there are large databases of individual chemicals that provide a kind of fingerprint in the mass spectrometer. The databases are large, so we already have a good starting point. We know what the peaks say about the molecule, they may signify that this particular fragment is this particular fragment. We can also use pure chemical compounds to run through the mass spec, to match and get signatures that way. When it comes down to the wire and we try to identify things that we don't know, we have to re-evaluate what all our tools are.
JB: Speaking of tools, I’m wondering about the Rapid Response Mobile Research Unit. Will you be going into the field with it this year or making any updates to it beforehand?
Dr. Bein: Yes, we will be actively chasing fires as they as a pop up. Right now, everything is in storage from the Winter and Spring, so we'll be dragging it out and do our estimate calibrations and systems testing and getting everything up and ready so it's just a matter of pulling up a truck and hitching and going. We have some new samplers and instrumentation that I'll be taking with me, looking at both the PM and gases.
We want to stay vigilant and continue to collect samples from season-to-season for archival purposes, as well as to continue these studies. Right now, we're focusing on acute exposure, a one-time exposure to the cell line, or using an animal model. But we also want to look at chronic exposures, where it happens over and over and over again through the lifespan of an animal. We use the animal as a model for human biology.
Chronic exposure studies are harder to run for a confluence of factors. One approach is to use the samples I've been collecting (if we have enough of them) and re-aerosolize them. We take them off the filter, put them in a solution and back into the particle form to do an actual inhalation exposure. We can do that repeatedly over longer periods and watch how the animals react. We can also make our own combustion system that replicates what and how a forest fire burns in a controlled environment in a laboratory and use that as another way to study the long-term effects of continued exposure to wildfire emissions. That’s where research is heading. Those are the knowledge gaps that we have: The acute, what are the chemical compounds that are toxic, and the long-run, what's happening as people continue to be exposed summer after summer.
"Being mindful of the conditions primed for burning, being a little bit more cautious, preparing for PG&E emergency shut offs, being aware of red flag warnings and knowing the areas that are most susceptible are tools giving us an advantage to make this fire season not as bad as it could be."
How bad will it be this year and are you ready?
Dr. Bein: That's a great question. As everybody knows the conditions are primed with the drought and temperature, so really the X Factor is the ignition source. The ignition source is something that we have control over—human error or electrical lines. The things we can't guard against are like the anomaly of last year, the dry lightning siege, which doesn’t frequently happen in California. I don't expect that this year. In the absence of that, the real question is how bad is going to be if we've learned some lessons about how to be more mindful of how quickly a fire could be sparked, ignited and spread?
I'm hoping that we've learned some lessons and maybe this season won't be as bad as it potentially could be, but it remains to be seen. On a personal level—sparks from machinery, driving, rocks on the road (like the Carr Fire)—you can start a wildfire in a bunch of different ways, so being mindful of the conditions primed for burning, being a little bit more cautious, preparing for PG&E emergency shut offs, being aware of red flag warnings and knowing the areas that are most susceptible are tools giving us an advantage to make this fire season not as bad as it potentially could be. I'm hoping for the best.
JB: In past years, you had trouble getting permission to take air samples from wildfires as they were burning. Did you ever find a good contact in Cal Fire to help you collect data or is that still something that’s not been resolved fully?
Dr. Bein: That has not been resolved fully. There have been a lot of conversations and discussions going on, not only with Cal Fire but also local fire agencies, where I'm continuing to get the feedback that I just need to call whatever fire battalion is on patrol and that's the best way to get in. So rather than going from the top down, going from the bottom up. Another idea I have is recruiting firefighters to teach them how to use this particular device (the Rapid Response Mobile Research Unit) and having a collaboration with them. They could be responsible for following their fire crews. So there's a couple things on the table that I'm pursuing right now. We'll see if it works or not.
JB: Any concluding thoughts?
Dr. Bein: People have some control. You can be mindful of your activities, surroundings and what you're doing; if you're playing with fire, using fire for whatever reason or using machinery, you have some control. I just hope that we can be as safe as possible when doing what we do.
Definitely take precautions. Get air purifiers now before they sell out. Get masks—not the cloth mask we wear for COVID—the N95s (the cloth mask will not protect you from smoke). Get your Go Bag, sign up for text alerts from your county or the state. Be aware of Cal Fire's web page. Know to get out quickly, where evacuations, fires and winds might happen. Protect yourself and your family.
Jennifer Biddle is a digital strategist and science writer/producer. She produced the Emmy-nominated documentary Waking Up to Wildfires.