Wildfires

Fires release particulates and heavy metals into the air. Trees absorb heavy metals, but when homes and other man made structures burn, that's when the pollution is the worst.

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METAL TOXIN THREAT IN WILDLAND FIRES DETERMINED BY GEOLOGY AND FIRE SEVERITY

Accentuated by climate change, catastrophic wildfires are a growing, distributed global public health risk from inhalation of smoke and dust. Underrecognized, however, are the health threats arising from fire-altered toxic metals natural to soils and plants. Here, we demonstrate that high temperatures during California wildfires catalyzed widespread transformation of chromium to its carcinogenic form in soil and ash, as hexavalent chromium, particularly in areas with metal-rich geologies (e.g., serpentinite). In wildfire ash, we observed dangerous levels (327-13,100 µg kg−1) of reactive hexavalent chromium in wind-dispersible particulates.

Lopez, A.M., Pacheco, J.L. & Fendorf, S. Metal toxin threat in wildland fires determined by geology and fire severity. Nat Commun 14, 8007 (2023). https://doi.org/10.1038/s41467-023-43101-9

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BEYOND PARTICULATE MATTER MASS: HEIGHTENED LEVELS OF LEAD AND OTHER POLLUTANTS ASSOCIATED WITH DESTRUCTIVE FIRE EVENTS IN CALIFORNIA

This study finds elevated concentrations of metals mobilized by wildfires destroying infrastructure in California over the last decade, raising potential health concerns for downwind communities.

Boaggio, Katie et al. “Beyond Particulate Matter Mass: Heightened Levels of Lead and Other Pollutants Associated with Destructive Fire Events in California.” Environmental science & technology vol. 56,20 (2022): 14272-14283. doi:10.1021/acs.est.2c02099