Cynthia F. Isley, Mark Patrick Taylor
Year Published:

Cataloging Information

Fire Effects
Smoke & Air Quality
Smoke & Populations
Smoke Emissions

NRFSN number: 22439
FRAMES RCS number: 61855
Record updated: January 12, 2021

Globally, wildfires are increasing in frequency and severity, exposing populations to toxic trace elements stored within forests. Trace element and Pb isotope compositions in aerosols (n = 87) from four major wildfires near Sydney, Australia (1994-2004) were evaluated (Mood’s median test) to determine any significant differences in concentration before, during or after wildfires. The USEPA’s positive matrix factorization (PMF) model was used to distinguish a wildfire-related particulate source factor. Atmospheric concentrations of Cd and Mn were approximately 2.5 times higher during fire periods. PMF modelling distinguished a soil factor (Ca, Si, Ti and Zn) and an anthropogenically-sourced factor (Cd, Pb). The Cd, Pb anthropogenic factor was present at twice the concentration during wildfire periods (compared to before or after). Lead isotopes revealed that former leaded gasoline depositions were subject to remobilization during post-2000 wildfire periods. Trace element increases during wildfires are unlikely to exceed health-based criteria.

Wildfires release metal contaminants, Cd and Pb, from past anthropogenic emissions into the atmosphere. These were not found to be at a level of concern for health risk.


Isley, Cynthia F.; Taylor, Mark P. 2020. Atmospheric remobilization of natural and anthropogenic contaminants during wildfires. Environmental Pollution 267:115400.

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