Wildfire Smoke: A Growing Health Crisis for Vulnerable Populations
Recent catastrophic wildfires in Australia (2019-2020) and Los Angeles (2025) have sparked urgent research into the short-term and long-term health effects of smoke exposure. The findings are particularly concerning for vulnerable groups: pregnant women, children, and urban residents.
The Black Summer Bushfires: Australia, 2019-2020
Hundreds of fires burned millions of hectares, affecting over two-thirds of Australians. In Canberra, air pollution readings exceeded 5,000—far surpassing the hazardous threshold of 300.
"The exposures in utero... can have consequences for many years — the rest of their lives."
— Sotiris Vardoulakis, University of Canberra
One pregnant woman, Anneke French, experienced a placental abruption. Her daughter Margot was born prematurely and underweight, later developing asthma and eczema. The attending obstetrician reported visible smoke in the operating room.
Los Angeles Wildfires: January 2025
The Eaton Fire destroyed approximately 9,000 buildings and killed 19 people. The Palisades Fire impacted roughly 20 million people across the region.
Irene Farr and her family evacuated with their 11-month-old daughter Azul. They did not return home for over a year due to concerns about lingering toxins from burned structures and infrastructure.
What Makes Urban Wildfire Smoke So Dangerous?
Analyses reveal that smoke from Los Angeles urban wildfires was particularly hazardous due to the burning of both vegetation and man-made materials: plastics, car batteries, and asbestos tiles.
- Official air quality monitors registered elevated levels of lead and arsenic miles from the fire sites.
- UCLA researchers measured high levels of benzene, a carcinogen, outdoors while fires were active.
- After fires stopped, outdoor benzene levels fell—but other hazardous gases, including toluene and carbon tetrachloride, increased inside homes weeks later. This suggests homes can absorb and re-release gases from drywall and furniture.
- Another research team identified hexavalent chromium, a carcinogen, in the air around cleanup sites weeks after the fires.
- Lead and other heavy metals remained high in some homes and soil after initial cleanup efforts.
"If something gets burned that's not a traditional wildfire compound, if you don't specifically look for it, you're not going to find it."
— Yifang Zhu, UCLA air pollution researcher
"We are facing an entirely new challenge when wildfires burn into major cities."
— Mike Kleeman, UC Davis
Health Impacts: What the Data Shows
General Population (Los Angeles)
Research using data from the Cedars-Sinai emergency room—located near the Palisades fire—revealed dramatic health impacts in the 90 days following the fires:
- 24% increase in respiratory issues
- 47% increase in heart attacks
- Over 100% increase in abnormal blood tests**, including unexpected blood sugar readings, disrupted immune system indicators, and altered metabolic profiles
Researchers anticipate longer-term health problems, including heart issues and mental health stress. Ongoing studies include a UCLA-led project tracking health changes in over 4,000 individuals, as well as studies focused on firefighters and first responders.
Pregnant Women and Children
General air pollution is already linked to preterm birth, low birth weight, and chronic diseases. Early studies suggest wildfire smoke carries similar risks, with some research showing associations with asthma in babies and autism diagnoses.
However, evidence remains limited due to a lack of standardized research methods and funding. Australian government funding for bushfire health research was limited to just $5 million. Biological samples from pregnant women during the Black Summer fires were not systematically collected or studied.
"I don't think we're any better prepared to deal with an environmental catastrophe like this than we were the last time around."
— Stephen Robson, obstetrician
Critical Gaps in Research and Infrastructure
Researchers have identified several systemic failures:
- Air monitoring systems are not equipped to capture all pollutants from urban wildfires
- No standardized global protocols exist for studying wildfire health impacts
- Funding uncertainty for long-term studies, with private philanthropy filling gaps left by shifts in federal research priorities
- Lack of standardized testing protocols and coordinated guidance for post-fire cleanup
"We need a universal scientific protocol to harmonize datasets across countries."
— Christopher Nolan, endocrinologist
How to Protect Yourself from Future Fires
Recommendations from experts:
- Wear N95 masks or respirators when outdoors
- Use HEPA-rated and carbon filters indoors and in car air-handling systems
- Thoroughly clean dust and ash from living spaces
- Consider low-cost air monitors for tracking indoor air quality