Lead supervisor: Richard Harrison, Earth Sciences
Co-supervisor: Vito Mennella, MRC Toxicology Unit; Emilie Ringe, Departments of Earth Sciences and Materials Science and Metallurgy
Brief summary:
Exposure to fine Particulate Matter (PM2.5) is the leading environmental contributor to the global burden of disease; use state-of-the-art magnetic and microscopy methods – at the intersection of environmental science and toxicology – to help answer why.
Importance of the area of research concerned:
Exposure to fine Particulate Matter (PM2.5) is the leading environmental contributor to the global burden of disease. Our recent work in the London Underground (LU) showed workers are exposed to concentrations of PM2.5 found in subway systems which are up to 100’s of times higher than above ground due to the emission and build-up of metallic magnetic wear products (wheels, brakes, rails etc.) and their resuspension by moving trains. This exposure is common on subway systems around the world but especially in older subway systems, such as the LU, where large sections of the network suffer from both accumulated dust and poor ventilation, and aging rolling stock. PMs from these sources are very rich in iron and have been shown to penetrate into the airway epithelium cells driving oxidative stress. However, it remains unknown how subway PMs cause toxic responses in the airway and whether this poses a significant risk to human health, and whether this particular source of PM is more of less toxic than other sources.
Project summary :
We aim to transform our understanding of this key issue using a multi-disciplinary approach that connects recent breakthroughs in the fields of materials science, mineral magnetism, electron microscopy, and toxicology. This project builds on existing collaborations that have analysed the particle composition of the London tube using innovative imaging and magnetic monitoring technologies that cross conventional disciplinary boundaries. This project will yield breakthroughs in our understanding of the pathways to toxicity by establishing a feedback loop between the nanoscale materials science of particles (their chemistry, oxidation state, structure and 3D morphology) and spatially correlated in vitro toxicological analyses of their biological impact.
What will the student do?:
Environmental magnetic methods to monitor PM in urban environments will provide a rapid and effective means of assessing particle size distributions (down to the sub-5 nm level) as well as their chemistry, oxidation state and nanoscale 3D morphology. We will develop improved magnetic monitoring approaches to fingerprint the source and determine the age of the PM (e.g., by distinguishing freshly generated versus legacy dust and comparing to synthetic analogues of known age) and to quantify the changes in pollution quantity and quality across various microenvironments (e.g. LU). Our integrated particle-scale chemical, magnetic, morphological and in vitro results will guide the development of improved magnetic monitoring and mitigation methods, which can then be designed to target those particles identified as the most concerning from a public health perspective.
References - references should provide further reading about the project:
Sheikh, H.A., Tung, P.Y., Ringe, E., and Harrison, R.J. (2022) Magnetic and microscopic investigation of airborne iron oxide nanoparticles in the London Underground. Scientific Reports, 12, 20298.
Sheikh, H.A., Maher, B.A., Karloukovski, V., Lampronti, G.I., and Harrison, R.J. (2022) Biomagnetic Characterization of Air Pollution Particulates in Lahore, Pakistan. Geochemistry, Geophysics, Geosystems, 23, e2021GC010293.
Tung, P., Sheikh, H.A., Ball, M., Nabiei, F., and Harrison, R.J. (2023) SIGMA: Spectral Interpretation Using Gaussian Mixtures and Autoencoder. Geochemistry, Geophysics, Geosystems, 24.
Applying
You can find out about applying for this project on the Department of Earth Sciences page.