What Every Angeleno Should Know after the L.A. fires

Published on Medium.com on January 18, 2025

Aftermath of January 2025 urban fire in Los Angeles; photo by ABC7

While the Los Angeles cataclysmic fires were raging, just about everyone uploaded the Watch Duty app on their phones as debates erupted about fault or management.

But now as evacuees started returning to check on their properties, cautions concerning toxic conditions were being expressed by environmental experts. In the last few days, two seminars addressed the issues presented by the urban wildfires that local authorities should be considering.

The LA Wildfire Impacts: Air Quality & Human Health with Experts seminar was presented by Argos Scientific, which installed BTEX and methane monitors in the Porter Ranch area in 2022 as part of a consent decree resulting from the 2015 Aliso Canyon blowout. The panel featured Michael Jerrett, professor of environmental science at UCLA, who’s a principal investigator on the team conducting research into the health effects from the Aliso disaster. Another professor discussing the Los Angeles fires was Jochen Stutz of the UCLA Department of Atmospheric and Oceanic Sciences, who designed the Porter Ranch monitoring system. A third member of the panel was Eric Stevenson, who had been the Director of Meteorology and Measurement at the Bay Area Air Quality Management District and is currently working at Argos as the Strategic Director.

Dr. Jerrett discussed the concerns about the public health aftermath of the Los Angeles fires. The first concern regarded the trauma and post-traumatic stress disorder (PTSD) caused for evacuees, including heightened levels of anxiety and depression. He mentioned studies conducted after the 2016 Fort McMurray fire in Canada which showed that these issues can continue for years after such a disaster.

The second concern was the “release of very complex and poorly understood air pollutant mixtures” that would have an effect, especially for those who were closer to the burning structures. Jerrett said there was a lot of confusion for many who saw their PurpleAir monitors or the AirNow site showing that the air quality levels were now okay, pointing out that these monitors don’t measure the secondary formation of particles that can be highly toxic. He said there could be a wide array of health effects from these particles ranging from respiratory distress to cancer formation in the longer term, adding that there aren’t any good studies that look at the impacts of repeated wildfire exposure, especially as they are becoming “the new normal” in every region in the state. He mentioned sustained exposure to particulate material, ozone, nitrogen oxide and some organic compounds could cause serious diseases such as heart attacks, asthma, COPD, and diabetes.

Slide from Air Quality and Human Health seminar

The professor also discussed the possibility of mental health problems. He said the particles can be very small so they can enter through our lungs and bloodstream. Once they’re part of the circulatory system, they can deliver toxins right to the brain. He also mentioned there is growing, but not yet conclusive, evidence of dementia, referring to a recent study regarding wildfire smoke’s effects on seniors.

He brought up a finding released in 2024 regarding pregnant women and exposure to toxic chemicals in the study looking into the short and long-term health effects from the Aliso blowout.

He would like to see a study involving those who had to evacuate, including the collection of baseline biological samples and bloodwork, as well as from those near the fires who didn’t evacuate.

He next turned to the remediation period that will be part of the recovery from the fires, bringing up “a critical concern” as there will be homes that survived the fire but have been heavily penetrated by smoke. He said there are guidelines by the Industrial Hygiene Association of America, but warned there could be many companies that will say they will provide cleaning for homes but have questionable methods.

He mentioned research his department did last year that gave them an estimate of approximately 54,000 people in an eleven-year period between 2009 and 2019 that had likely died as a result of wildfire smoke exposure with an estimated economic impact of more than $430 billion. He said that telling homeowners to create defensive space, harden up their home’s structure and change their roofs isn’t enough. “You need to give them subsidies,” adding that there needs to be more help akin to programs that incentivize solar power and electric vehicles.

The CEO of Argos Scientific, Don Gamiles, asked Jerrett about the air quality index when it comes to urban wildfires. Jerrett said that during a wildfire, the AQI will be driven by the particulate matter. But “when we look at the air quality index, the concern with the wildfire smoke is that there are many substances, poly aromatic hydrocarbons, the volatile organize compounds that can adhere to the particles so you’re supercharging the toxicity.” He said the AQI may say the particles are low but they are really ten times more toxic than they are normally.

As for another concern, Jerrett talked about the formation of formaldehyde, a group one carcinogen and a serious respiratory irritant, that is not measured by the air quality index. That chemical and other harmful compounds can affect every organ system in the body, including interfering with the delivery of oxygen to the bloodstream, arteriosclerosis, increased blood pressure, and diabetes.

Regarding the use of N95 masks and whether they would provide adequate protection for those returning to the affected areas, Jerrett said, “If someone is going back into their homes with a lot of VOCs, this mask isn’t going to protect them.” He recommended using masks that protect against vapor intrusion.

Eric Stevenson talked about lessons learned from the 2020 Santa Rosa fire that wiped out a large section of that city. He said they saw additional impacts specifically during clean up. When “the debris was collected and thrown away, there were additional pollutants that were re-entrained into the air. He said that after some homeowners cleaned up their houses when other neighbors then cleaned up their homes, there was contamination with the re-entraining of the pollutants, impacting their homes. He said “There has to be some sort of strategy” to prevent this further contamination while clean-up occurs in fire areas.

One attendee, Assad Alnajjar, who’s a senior engineer with the City of Los Angeles and is on the Porter Ranch Neighborhood Council, talked about the importance of involving nonprofits and deputizing people who can be trained ahead of disasters so that they can help.

Dr. Jerrett discussed the lessons learned from the Aliso disaster. “We really don’t know what’s in the mixtures when we have these disasters that are relatively unprecedented”, he said, adding that it’s important to measure as much as possible so a baseline is established so that people would know what they’ve been exposed to. “With Aliso, one thing that tipped the tide in terms of getting Public Health on board was showing them it wasn’t just an outdoor air problem.” His team went into homes to do swab tests that showed there was a significantly elevated level of benzene that wasn’t from the gas itself but from the oil droplets that were emitted when the facility depressurized. He emphasized that it’s important to measure while the event is happening and shortly thereafter.

“Once you get to a year down the line, you’re into really complicated exposure reconstruction. There’s no substitute for having that baseline information. Ideally, we would want to be out there right now recruiting people to get them into health surveys,” Jerrett said. He said that exposomics research into identifying environmental factors that contribute to disease has “changed the way that we’re able to detect contaminants in people’s bloodstreams and saliva,” adding that examining the molecules would be a prognostic indicator for future health effects, but that kind of research needs to start immediately to get the baseline samples.

He mentioned a study conducted by one of his former students, Colleen Reid of the University of Colorado Boulder, that looked into symptoms experienced by residents whose homes survived the 2021 Marshall fire. Among the problems reported were headaches, sore throats, and strange tastes.

Another panelist, Stutz, did have to evacuate from the Palisades fire area. The others on the panel were in agreement that his home, which fortunately survived the fire, would be one location to test for toxic material.

The other webinar was hosted by the Coalition for Clean Air and was entitled “The Fires: Air Quality, Public Health & What to Do Next.” As with the other seminar, this one discussed many of the same topics that will be of importance to Angelenos.

Tim Dye, president of TD Enviro discussed the pollutants, PM 2.5, PM 10, CO, and ozone that will be found in the smoke during the fires, and the AQMD website that can be accessed to get information about current air quality measures. Story Schwantes, also from TD Enviro, explained the U.S. EPA’s websites airnow.gov and fire.airnow.gov, which measure PM 2.5, PM 10 and ozone. Dr. Joseph K. Lyou, the president and CEO of the Coalition for Clean Air, cautioned that not all the potential toxins are measured.

Jane Williams, Executive Director at California Communities Against Toxics, pointed out that the air quality index (AQI) doesn’t measure the contaminates and pollutants that are a major concern regarding the fires because of the cost involved. Anyone who returns to the affected communities, she said, should wear proper PPE as they could be breathing hydrogen cyanide, hydrogen fluoride, hydrogen chloride, polycyclic aromatic hydrocarbons (PAHS), dioxides and furans, volatile organic compounds (BTEX & formaldehyde), and metals. These compounds will absorb onto particulate matter along with materials that are burned in homes and cars, including lead-based paint, plastics, concrete, electronics, and asbestos.

Calling what’s happening in Los Angeles, a “disaster after the disaster,” she said there is a powerful psychological drive for evacuees to want to return home.

Dr. John Balmes described the association between smoke and respiratory health, with risks for exacerbation for asthma, COPD, and respiratory infections such as pneumonia and acute bronchitis. An added risk is that COVID is still present and in evacuation shelters may also pose a risk for evacuees. (A norovirus outbreak was reported in one shelter.)

Dr. Gina Solomon discussed the problems with contaminated water. “In areas with active fire, we’re most worried about the drinking water.” She talked about 15 homes that survived the 2017 Tubbs fire in Santa Rosa in which contaminated water was found. She added that with the 2018 Camp Fire in Paradise, microbial and VOC contamination were found. She advised that the water should not be used, even for showering, until the water lines have been checked, which may require the lines to be flushed repeatedly and may even need to be replaced.

Engineer Ed Avol talked about how exposure to these chemicals can affect the ability to focus as well as affect mental health. He warned that many of the particles may be too small to see but can easily get into one’s circulatory system and “can even get into the brain.” As for distance, if one can see ashes on their window sills or their vehicles, that would indicate that the winds have blown the toxic material in their direction.

He said that for children, as their lungs are growing, any long term exposure can affect them for the rest of their lives

Dr. Rania Sabty said that N95 masks may not be enough to protect from hazardous materials. She advised that to be safe during cleaning up a house after a fire one should make sure to have an up-to-date tetanus shot and make sure to avoid standing under equipment and objects that may fall. She also gave recommendations for protective clothing, gloves, and respirators.

Citing lessons learned from the 2023 Lahaina fire, Williams warned about PTSD and anxiety. She mentioned that in the past, disasters could be politicized. An example of this was after the 9/11 attack when the head of the EPA was pressured by then-president Bush to say that the air was safe. That messaging turned out to be wrong as the health impacts from the ash and smoke were significant and lasted years.

With the Lahaina disaster, there was much re-entraining of contaminants back into the environment while trying to excavate the massive amount of ash. Developers were pressuring residents to sell so she is concerned about similar pressures and rent gouging here in Los Angeles.

There are many articles concerning toxic materials released by the fires, including one by the AP that have been published since these webinars. Cal Tech researchers studied the amount of toxins, including lead, released by the Eaton fire. To be sure, more studies will be published in the months to come.