Hello and welcome to another week of Cancer Briefing! Today, I was reading a paper in Nature Communications Earth & Environment relating to toxin exposure from the LA fires last year. Nature released this paper last month, though it’s technically not yet published and is an unedited manuscript.
The major finding of this paper is that the investigators discovered hexavalent chromium in airborne ashes produced by the LA fires in 2025. This is a known human carcinogen and can cause cancer by directly mutating cells. What’s concerning about this research is not only the implication that chromium-6 is produced in urban fires, but also that computational models suggest the toxin may be persisting in the environment at elevated levels.
“Residents living adjacent to wildfire cleanup zones should take steps to reduce hexavalent chromium exposure by using indoor air filters and limiting outdoor exercise in the fire zones until conditions return to safe levels,” the investigators write in their discussion.
For me, this underscores that there’s actually quite a large gap in our knowledge around what the long-term health risks of wildfires are, and how the contaminants from these fires behave over time. It’s something that we do need to understand better, I think, considering that wildfires are only becoming a greater risk to us all.
