Staff and Postgraduate Students
Miss Claire Nattrass
2011-present: Durham University: PhD in Geology
2008-2011: University of York: Bsc Environmental Science (1st class Hons with distinction)
2. Current Research
Volcanic ash and diatoms: unravelling crystalline silica toxicity
I joined the Department of Earth Sciences and Institute of Hazard, Risk and Resilience in October 2011 as a PhD student. My research explores the potential toxicity of dusts rich in crystalline silica, with particular reference to the threat posed by cristobalite, a known carcinogen and cause of disease such as silicosis. Previous studies have shown the toxicity of cristobalite to be highly variable, including volcanic cristobalite where ashes with high concentrations of cristobalite have been shown to be much less toxic than predicted. Therefore, this project aims to increase the understanding of the variability of the toxic potential of cristobalite.
This key aim will be met by looking specifically at the effect that impurities within the cristobalite structure can have on its toxic potential. To achieve this, two sources of cristobalite will be studied: 1) Synthetic cristobalite and 2) diatomaceous earth powders. The synthetic cristobalite powders will be produced with varying quantities of Al and Na impurities added to them at Durham University. Processed diatomaceous earth powders will be sourced worldwide, as the processing procedure causes the amorphous silica in the dusts to convert to cristobalite. As diatomaceous earth is often found in close association with Al- containing clays it is thought impurities may be taken into the cristobalite structure during processing. A suite of analyses to characterise the physicochemical properties of the powders, followed by in vitro toxicological assays, will enable me to determine if impurities within the structure of the cristobalite in these dusts can affect the toxic potential.
This multi-disciplinary project allows me to branch into a number of research fields with the aim of providing a better understanding of the health hazards posed by these dusts.
- X-ray diffraction (XRD)
- Laser diffraction
- Brauner-Emmett-Teller (BET)
- Scanning electron microscopy (SEM)
- Electron microprobe
- In vitro assays (Haemolysis, LDH release, Alamar blue, cytokine release)
3. Research Interests
- Particle toxicology – particle-cell interactions
- Crystalline silica formation and structure
- Crystalline silica toxicity
- Health and environmental impacts of volcanic ash
- Occupational and environmental exposure to crystalline silica