Postdoctoral Fellowship: EAR-PF: Probing the metal chemistry of wildfire-generated nanoparticles

Wildfires greatly affect the environment and human health by creating small toxic particles. These particles, made under certain fire conditions, can get into the air we breathe, the soil, and the water, causing serious health and environmental problems. This project aims to study how different wildfire conditions and soil types affect the creation and properties of these toxic particles.

We are especially interested in very small particles, less than 2.5 micrometers (PM2.5) – for comparison, a human hair is about 50-70 micrometers thick, so PM2.5 particles are about 20 to 30 times smaller than a human hair. These small particles can be very harmful to health because they can easily get into our lungs when we breathe. By studying these processes, the research will help reduce the health risks from wildfire smoke and improve air quality.

This study will add to our scientific understanding and help find ways to protect public health during wildfires. The results of this research will benefit society by finding solutions to reduce respiratory exposure risks for farm workers, firefighters, restoration and fire-safety workers, recreationalists, and local communities. This research will also support education by involving students and working with local communities to raise awareness and inform policy decisions about the health risks of toxic particles from wildfires.

Wildfires are major contributors to the formation of toxic metal-containing nanoparticles, which pose significant health risks. Fire conditions and their influence on soils determine the nature of these nanoparticles and their chemical-physical properties, which are largely unknown. The proposed project aims to: 1) determine how temperature and the composition of combustible materials, combined with soil composition, control fine particulate metal chemistry; 2) identify the mineralogy, metal associations, and morphology of particles; and 3) determine how geology and vegetation influence the metal chemistry and mineralogy of nanoparticles in soil, ash, and wildfire smoke.

The Fellow will conduct lab burning experiments and prescribed burns. The particles formed during burning and soil heating experiments will be collected and analyzed using advanced techniques, including transmission electron microscopy (TEM), synchrotron X-ray absorption spectroscopy (XAS), small-angle X-ray scattering (SAXS), and single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS).

By linking lab experiments with field measurements, this study aims to understand how fire conditions and soil properties affect the formation, transformation, and reactivity of fire-generated nanoparticles and to evaluate their health impacts. This knowledge is crucial for evaluating the health risks posed by these particles and for developing strategies to mitigate their impact.

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.