More-intense wildfires release more arsenic

When wildfires reach sites contaminated with arsenic, the extreme heat can release that arsenic to the wider environment. But just how much arsenic is emited during these wildfires remains tough to predict. In a new study , researchers led by Marek Tuhý at Charles University have determined at which temperatures certain minerals and compounds release their arsenic ( Appl. Geochem. 2025, DOI: 10.1016/j .apgeochem.2025.106318). The researchers say understanding these mechanisms is becoming more important as wildfires grow in size and intensity. To understand arsenic release, the researchers first selected arsenic-containing compounds and minerals that are commonly found in contaminated or naturally arsenic-rich soil, such as sulfides, sulfosalts, arsenic oxides, and arsenates. The selection also included a dried and pulverized sample of an arsenic-rich mushroom to represent biological samples. Using a cylindrical furnace, the scientists then slowly heated the samples from 25 °C to around 800 °C. As the temperature climbed,