Wildfires can unlock cancer-causing chemicals from the soil, new research finds

[...]

“In the complex mixture of gasses and particles that wildfires spew out as smoke and leave behind as dust, heavy metals such as chromium have largely been overlooked,” Scott Fendorf, co-author of the study and professor at the Stanford Doerr School of Sustainability, said in a press release.

Chromium is common in soils across the western United States, Australia, Brazil, Europe, Indonesia and South Africa.

Certain natural chemical processes can trigger a transformation of the metal from a benign form, called chromium 3, into a carcinogen called hexavalent chromium, or chromium 6. The toxin — which became infamous through the 2000 film “Erin Brockovich” — can cause cancer, organ damage and other health issues.

[...]

Fendorf said much of the health risk typically wanes after the first big rainfall washes the metals away. But it could take weeks or months for rain to arrive after a fire, especially as climate change increases the likelihood and frequency of drought.

[...]