RAPID: Concentration and Form of Metal and Metal-Baring Nanomaterial Contamination in Maui Fire Ash and Soil

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

Wildfire activity and associated environmental impacts have increased dramatically in recent years as a result of climate and societal changes. Fire liberates and alters the properties of metals stored in plants, soils, and structural materials, rendering them more soluble, reactive, and potentially more hazardous to environmental and human health. This Rapid Response Research (RAPID) project will collect time-sensitive samples and data related to the Maui fire. In particular, this research will examine the 1) concentration, composition, and properties of metals and metal-bearing nanomaterials, and environmentally persistent free radicals in fire ash and soil collected following the Maui fire, 2) estimate the lung bioaccessibility of metals from fire ash, and 3) the mobilization of metals and nanomaterials in fire ash into surface water receiving runoff from burned areas. The data generated in this project will be shared with local Maui residents and communities in a timely manner to assist the Maui community in understanding the contaminants left over on the ground in their homes, businesses, and land following the catastrophic Maui fire and the potential environmental and human health risks of such contaminants. This project will support the training of two graduate students. Methods, data, and tools generated in this project will be integrated into existing undergraduate and graduate curricula at the University of South Carolina and California State University. The combustion of vegetation and structural materials in the wildland-urban interface leaves behind fire ash which is typically enriched in metals and metal-bearing nanomaterials. Additionally, the high temperature, limited oxygen, and release of reducing agents due to pyrolysis of organic matter in the fire environment alters the properties of metals and metal-bearing nanomaterials, potentially transforming them to more mobile and reactive materials compared to their native counterparts. Rainfall generates overland runoff which further mobilizes metals and nanomaterials in the fire ashes to downstream surface waters, potentially causing environmental and human health concerns. This Rapid Response Research (RAPID) project will collect time-sensitive ash, soil, and water samples and data related to the Maui fire with the aim to 1) quantify the concentration metal, metal bearing-nanomaterial, and environmentally persistent free radicals in the wildfire-urban interface fire ash and soil collected following the Maui wildland-urban interface fire, 2) characterize the properties, with particular focus on metal speciation, of metal-bearing nanomaterials in fire ash and soil, and 3) estimate the lung bioaccessibility of metals from fire ash using established metal solubility assays in artificial lung fluids. The proposed research will provide a comprehensive understanding of the nature, concentrations, and transformations of metals, metal-bearing nanomaterials, and environmentally persistent free radicals in the fire environment. These data will be generated by adopting a state-of-the-art multi-method approach to characterize the properties of incidental nanomaterials including single particle-inductively coupled plasma-time of flight-mass spectroscopy, high resolution-transmission electron microscopy, X-ray diffraction, X-ray absorption spectroscopy, and electron paramagnetic resonance. The major and most important broader impact of the proposed research is to assist the Maui community in understanding the contaminants left over on the ground in their homes, businesses, and land following the catastrophic Maui fire and the potential environmental and human health risks of such contaminants. Other broader impacts of the proposed research include: 1) identifying novel questions and guiding future research in the area of fire-borne contamination; 2) generating datasets useful to other fields such as public health to better understand diseases linked to exposure to fire-emitted contaminants; and 3) enabling use of the generated data by public utilities such as drinking water treatment plants, to ensure appropriate processing of drinking water. 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.