RAPID: Investigation of Nano-scale Metals in Ash from the Marshall Fire, Colorado

Colorado School Of Mines, Golden CO

Investigators

Abstract

Wildfires are becoming more prevalent and are expanding out of wilderness areas and into the wildland-urban interface, including densely packed suburbs. The most devastating effects of these fires are apparent: the loss of homes, communities, and sometimes lives. However, beyond the physical destruction, one of the unanswered questions about the environmental impact of structure burning is whether fire liberates metal particles from household and structural components. Metals are found in everything from pipes to electronics to paints and pigments. Metals such as lead, copper, zinc, cadmium, and others can be toxic to the environment and humans. Once released, the smallest of these metal particles can be transported by wind events with subsequent deposition by rain and snow throughout different environments. The December 31st 2021 Marshall Fire in Boulder County, Colorado resulted in over 1000 structures burned, with as yet unknown impacts on metal release to the surrounding environment. It is of pressing concern to rapidly analyze ash from burned structures for the presence of metal particles. In order to accomplish this, the research team at Colorado School of Mines is employing state of the art particle analysis techniques that are sensitive to specific metals to determine if metal particles are present in ash samples. If found, further analysis will determine if the concentrations are at significant levels, and if humans are at risk of toxicological effects. By leaching the ash with simulated biological fluids, the project will assess the potential for metals to be absorbed by human lungs. This project will provide essential information to increase understanding of fire-derived metals while furthering our analytical capabilities via application to complex natural systems. Beyond the scientific goals of this project, community outreach and education are of high priority. Community members will be invited to participate in sample gathering and data analysis. The research team seeks to hold virtual and classroom forums involving the Boulder community, from the high school level to others within the general populous. These presentations will be aimed at educating the community on the findings of the research, sharing the health impacts of nanoscale particles, and providing hands on experiments for students. As climate change induces desertification of the environment, wildfires are becoming more prevalent and more devastating. Wildfires are expanding out of wilderness areas and into the wildland-urban interface, including densely packed suburbs. The Marshall Fire in Boulder County, Colorado recently burned over 1,000 homes and many other structures. The ash and smoke generated from this fire has the potential to be more harmful to both the environment and human health than materials generated from wildland fires. Specifically, the anthropogenic materials burned may lead to the presence of metal-containing nanoparticles (diameter < 100 nm) in the resulting ash/soot. The project goal over the next 12 months is to determine the amount of metal (Cu, Cd, Hg, Pb, Zn among others) present in the nanoparticle form in ash and soot. The research team will collect samples from the area impacted by the Marshall fire, focusing on ash from within burned homesites, nearby soils, and surface waters located downwind of the burned area. Samples collected in non-urban, upwind sites will act as controls. This RAPID project will utilize the novel technique of single particle ICP-MS to detect and quantify the nanoparticles present in deionized water suspensions. The research team will investigate the effects of particle size on metal bioaccessibility by performing single particle ICP-MS analysis as part of dissolution experiments using simulated lung fluids. Timely analysis of the burned materials will advance knowledge of metal speciation in post-fire debris and may inform a responsible remediation effort with respect to human health and environmental impact. Beyond the scientific goals of this project, community outreach and education are of high priority. Through a “citizen science approach”, community members will be invited to participate in sample gathering, with results being communicated back to the participating homeowners. The research team will hold virtual and classroom forums involving the Boulder community, from the high school level to others within the general populous. These presentations will be aimed at educating the community on the findings of the research, sharing the health impacts of nanoscale particles, and providing hands on experiments for students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.