Title: Pyrogenic Remobilization and Fate of Toxic Trace Elements
Abstract: Anthropogenic emissions over the past century have substantially increased the levels of toxic trace elements (e.g., lead) in the biosphere. Understanding the physical and chemical processes that drive the cycling of these contaminants is important for protecting human and environmental health. This presentation will focus on my work exploring the impacts of fire on the mobilization and fate of contaminants in two regions: Western United States and Patagonia in Chile.
In the Western United States, I investigated the impacts of recent wildfires on the remobilization of toxic elements, with a focus on lead. I used geochemical profiles, including lead isotopes, to assess how the historic use of leaded gasoline has contributed to fire-remobilized lead at two contrasting sites in California. In Patagonia, I investigated the mobilization of toxic elements in response to large-scale fires that were set during European colonization in the region. The results show a positive relationship between fire size and the flux of metals. These findings have strong implications with respect to climate change because the frequency and intensity of wildfires are expected to increase.