In a collaborative project between Stanford University and the Canadian Light Source at the University of Saskatchewan, researchers are exploring the link between wildfires, toxic metals, and the soil’s seemingly built-in repair system.
Dr. Derek Peak from the College of Agriculture and Bioresources says naturally occurring metals that are embedded in our soil are generally harmless, but when heated to temperatures between 800 and 1200 degrees Celsius, usually by a wildfire, these metals can turn toxic.
For example, when heated, chromium turns into deadly Chromium VI. He says they that around 10 per cent of the soil’s total chromium converts to chromium VI when heated at between 600-and 800-degree temperatures, and as the temperature increases, so does that per centage.
However, another metal is standing by in the dirt with it, silently doing damage control.
“Fires make Chromium VI, and they also make Iron II and Iron III minerals, and then those minerals react with the Chromium VI, and they return it to Chromium III.”
Peak says the findings suggest it may be important to monitor the soil’s iron content following a wildfire, to ensure everything is able to return to normal.
He adds that the relationship between chromium and iron have been well documented and understood, but the interaction between the metal’s cycles in relation to wildfires is a fairly novel breakthrough.
Peak has also been sharing these rather novel findings to university students in his class: Soils in a Changing World.




















