Three times more likely to cause premature deaths, researchers find

Key Takeaways
- Smoke fromwildland-urban interface (WUI) firesis significantly more harmful to human health than smoke from wildfires in remote areas.
- A new study finds that emissions from WUI fires arethree times more likely to cause premature deathsdue to their proximity to populated areas.
- Scientists usedadvanced computer modeling and real-world datato analyze fire emissions and their health effects across different continents.
Risk to human health
A new study has revealed that fires burning through thewildland-urban interface (WUI)where wildland vegetation meets developed areaspose afar greater risk to human healththan wildfires in remote locations. Researchers found that emissions from WUI fires arethree times more likely to lead to premature deaths due to their proximity to densely populated areas.
The research, published inScience Advances, was led by scientists from theU.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR). Itanalyzed global WUI fire emissions using an advanced atmospheric chemistry model.
Their findings highlight the growing public health risks associated withincreasing WUI fires, particularly as urban expansion continues to push into fire-prone regions.
Even though the emissions of WUI fires are relatively small globally, the health impacts are proportionately large because theyre closer to human populations, said lead authorWenfu Tang, an NSF NCAR scientist.
The Growing Threat of WUI Fires
Thewildland-urban interfacenow makes up5% of the worlds land area(excluding Antarctica) and continues to expand across all populated continents. With this expansion has come a surge in devastating fires that have resulted in widespread destruction and loss of life.
Some of the deadliest WUI fires in recent history include:
- 2009 Black Saturday bushfires (Australia)173 deaths
- 2018 Attica fires (Greece)104 deaths
- 2023 Lahaina Fire (Hawaii)100 deaths
- 2025 Southern California Fires Destroyed16,000 structures, with estimated financial losses of$250 billionor more.
Previous research led by Tang showed that the percentage of wildfires occurring in WUI areas hasincreased significantly in the 21st century. The latest study builds on this by assessing thelong-term health effects of WUI fire smoke, beyond the immediate casualties of the fires themselves.
Why is WUI smoke more dangerous?
WUI fires are particularly harmful because they produce large amounts offine particulate matter and ozone precursors, which severely impactcardiovascular and respiratory health. Unlike wildfires in remote areas, the smoke from WUI fires affects large numbers of people,leading to more premature deaths.
Using theMulti-Scale Infrastructure for Chemistry and Aerosols (MUSICA)computer model, researchers simulated fire emissions and their impact on air quality. Their findings revealed that whileWUI fires made up just 3.1% of global fire emissions in 2020, they accounted for8.8% of all premature deaths linked to fire smoke exposure.
The impact varied across continents:
- North America: WUI fires represented6% of total fire emissions, but caused9.3% of premature deaths.
- Europe: WUI fires made up11.4% of total emissionsbut were responsible for13.7% of premature deaths.
Future research implications
A crucial next step in this research is examining thedifferences in emissionsfrom burning wildland vegetation versus burning man-made structures. Buildings containtoxic materialssuch as plastics, treated wood, and synthetic insulation, which may releasehighly hazardous pollutantswhen burned.
It is very important to have an emission inventory that explicitly accounts for the burning of structures, Tang emphasized. We need to know what is being burned in order to determine what is going up in smoke.
As WUI fires continue to rise due toclimate change and urban expansion, the studys findings highlight theneed for stricter building regulations, better fire prevention measures, and enhanced air quality monitoringin high-risk areas.
Posted: 2025-03-14 22:13:45