A new study reveals that wildfires and prescribed burns release about 21% more organic compounds into the atmosphere than previously estimated, contributing significantly to air pollution. These emissions, particularly intermediate- and semi-volatile organic compounds, can form harmful fine particles that linger in the air. The findings highlight overlaps with human-made pollution in regions like Southeast Asia, complicating efforts to improve air quality.
Wildfires have long been known to release a mix of gases and particles, but researchers now argue that the scale of this pollution has been underestimated. Published in Environmental Science & Technology, the study by a team led by Shuxiao Wang analyzed global data on burned land from forests, grasslands, and peatlands between 1997 and 2023. By incorporating volatile organic compounds (VOCs), intermediate-volatility organic compounds (IVOCs), and semi-volatile organic compounds (SVOCs)—often overlooked in prior assessments—the scientists calculated annual emissions at 143 million tons of organic compounds worldwide.
"Our new estimates increase the organic compound emissions from wildland fires by about 21%," said Lyuyin Huang, the study's lead author. She added that this updated inventory could support better air-quality modeling, health-risk assessments, and climate policy decisions.
The research drew from a global database of fire-affected areas and supplemented missing field data with laboratory experiments on burning vegetation. While human activities generate more total airborne compounds overall, wildfires match them in IVOC and SVOC outputs. This parity is most evident in emission hotspots such as Equatorial Asia, Northern Hemisphere Africa, and Southeast Asia, where fire-related and anthropogenic pollution intersect, posing unique challenges for mitigation.
These insights underscore the health risks of wildfire smoke, which can transform into breathable fine particles dangerous to inhale. As fires intensify with climate change, the study suggests a need for integrated strategies to address both natural and human sources of pollution.
