On USC’s University Park campus, 226 acres of untouched red brick located almost directly between the Eaton and Palisades fires that devastated Los Angeles, the air seems fine.
The first few days of the blazes left a fine coating of soot outdoors and sent air quality index numbers past 500, but now that the winds have blown that away, there’s little evidence of the nearly 50,000 acres burned or currently burning just miles away. If you squint, the landscape in the distance looks a little hazy. Maybe the night sky is slightly lighter than usual.
What you can’t see, however, is the dangerous particulate matter in the air.
“What is burning is actually buildings and building structures, and that produces a nasty, toxic mixing of the atmosphere. One that, in addition to all of these carcinogenic organic substances, contains asbestos,” said Constantinos Sioutas, co-director of the Southern California Particle Center.
The January wildfires, most notably the Eaton and Palisades fires in the Altadena and Pacific Palisades neighborhoods, are some of the deadliest blazes in L.A. history. They ignited on January 7, and are not yet fully contained. CalFire has reported 28 deaths and more than 15,000 structures destroyed as of January 25, but the true toll will remain unknown before more extensive damage assessments can occur.
USC and its surrounding neighborhood, located roughly 20 miles southwest of the Eaton fire and 20 miles southeast of the Palisades fire, is not in any immediate danger of burning. However, the entirety of the Los Angeles greater area is impacted by the smoke.
“In addition to the inherent toxicity of what they’re producing, it’s also the scale, the magnitude, it’s the area they’re affecting,” Sioutas, who is also a professor of civil and environmental engineering at USC, said. “The whole basin right now is just polluted.”
The L.A. basin is already one of the most polluted areas in the country. The American Lung Association ranks L.A. the worst city in the U.S. for ozone pollution and in the top 10 worst cities for year-round particle pollution. Average air quality in the city sits in the moderate category of the air quality index (AQI), between 51 and 100, which can be unhealthy for sensitive groups.
Although L.A.’s air quality is still poor in comparison with other cities, it has improved dramatically since the 1970s due to amendments to the Clean Air Act and reductions in vehicle and factory emissions.
“L.A. is really a success story in terms of air quality,” Dr. Sarah Van Orman, USC’s Chief Student Health Officer, said recently. “There’s a lot that has been done to improve air quality in Los Angeles, but… it’s important for people to realize that even without wildfires, there are days where Los Angeles has air quality that in particular may be unhealthy for people who are at risk.”
Now, on top of a baseline of poor air, the Eaton and Palisades fires have rapidly released unknown particulates into the atmosphere. But what makes this pollution different from L.A.’s usual smog, or the average wildfire?
Woodsmoke from wildfires releases hazardous chemicals including formaldehyde into the air, which can cause or exacerbate health conditions such as heart failure and asthma if inhaled, according to the Environmental Protection Agency (EPA). What makes the L.A. wildfire smoke more alarming is the amount of buildings burning in highly urban areas.
“[It’s] not only building materials, but then what’s inside that house. What if they had a bunch of gasoline stored in there? All that’s getting combusted, and that’s making its way into the air,” said Dick Sun, the deputy director of the USC Office of Environmental Health & Safety.
The New York Times reported dramatic spikes of lead and chlorine in L.A.’s air after fires erupted, likely caused by paint and pipes in old homes and plastic combusting. Asbestos from homes built before the 1980s has also been found in the air, which can cause mesothelioma, lung cancer and asbestosis.
Van Orman says those coming into direct contact with the wildfire material, like first responders or people re-entering burnt homes, should take the most precautions. People with preexisting lung conditions and chronic diseases, such as asthma, should also be cautious even without coming into direct contact with affected areas.
“If you can smell smoke or you can see ash or dust, you need to take precautions, and those will include limiting your time in that environment, wearing an N95 or higher grade respirator, considering wearing eye protection, wearing clothing that covers exposed surfaces, and then removing that clothing,” she said.
For those keeping close to USC campus, it’s harder to tell how safe the air is. The AQI ranged from 10 to 81 between January 16 and 21, but this doesn’t account for all the ash in the atmosphere.
Sioutas recommends wearing a protective face mask such as an N95 through the end of January, or for at least one week after the wildfires are fully extinguished. Van Orman and Sun suggest avoiding strenuous activity outdoors, wiping down indoor surfaces for dust and monitoring the AQI regularly. All three experts encouraged Angelenos to purchase air purifiers, which are an inexpensive and convenient way to keep pollutants out of the home.
AQI, while an incredibly useful tool that should be checked frequently in cities with poor air quality such as L.A., doesn’t capture all the impacts of the wildfires on the air. Ash, dust and other particulate matter blown in the strong winds may not be accurately reported by the AQI, the experts said.
There is no definitive answer on when air quality will return to normal, as it largely depends on meteorology and the longevity of the fires. While strong Santa Ana winds are still a danger, rain is forecast in L.A. this weekend, which can improve air quality and aid firefighting efforts.
When the dust clears, though, the air quality issue in L.A. will not disappear. Low-income populations are disproportionately affected by harmful air quality and pollution, and this tends to be worse in cities, according to the EPA.
“There’s still a lot of environmental injustice out there, unfortunately, in our underserved areas, where there’s just not enough resources or education to get people to really understand what all of this air quality really means for them, health-wise,” Sun said.
On top of this, California’s wildfires continue to increase in frequency and size with climate change. The state has 58 more annual “fire days,” or days with conditions that increase wildfire dangers, than it did 50 years ago according to CalMatters. Low rainfall, hot and dry conditions and strong winds all amplify these risks.
“These events are just going to become more common, and so there are a lot of parts that go to climate resiliency,” Van Orman said. “There’s public policy, there’s infrastructure, there’s emergency response, and those are things we know are really prominent in the public dialogue… But then there’s also individual preparedness.”
Students should continue to monitor AQI and invest in air purifiers and masks. Van Orman emphasizes personal accountability, as there is no immediate action the city can take to improve air quality beyond firefighting efforts. USC has various resources for wildfire and air quality education, including a wildfire FAQ page, a campus-specific AQI tool and an air quality FAQ page.