The Link Between Wildfires and Cancer-Causing Metal Toxins

The severity of wildfires and the geology of the affected areas play a significant role in the production of toxic hexavalent chromium (Cr(VI)) in particulates during and after fires. Soils derived from metal-rich geologies, such as ultramafic and mafic rocks, have higher concentrations of Cr(VI) compared to other soils. The concentration of Cr(VI) is significantly higher in severely burned areas compared to unburned soil. The surficial soil-ash layer, which is prone to wind erosion, contains elevated levels of Cr(VI) that persist even months after the fire. These findings highlight the potential respiratory exposure risk and long-term health concerns associated with metal toxins in wildfire smoke and dust.