The structural and elemental composition of inhaled particles in ancient Egyptian mummified lungs
[Thesis]
Montgomerie, Roger
David, Rosalie; White, Keith
University of Manchester
2013
Thesis (Ph.D.)
2013
Since the first modern investigations into Egyptian mummies in the 1970s, anthracosis and silicosis have regularly been found in mummified lungs (Tapp, 1975; Walker et al, 1987). Anthracosis, lung irritation caused by carbon particles, is well researched in modern populations but very little is known about the disease in ancient times. Similarly, little is known about the prevalence of silicosis, caused by the inhalation of particles of silicon, in ancient times. It has been assumed that carbon was inhaled through the combustion of fuel for cooking and illumination whilst silicon came from the desert environment.This study aims to test these assumptions by characterising the shape, size and elemental composition of the organic and inorganic particles contained within ancient lung tissue. When these particles are compared against surrogate carbon and silicon particles, it may be possible to identify them and reveal their aetiology.Surrogate carbon particles were produced through controlled combustion of fuels the ancient Egyptians are likely to have used. The modern silica containing sand was collected from various archaeological sites in Egypt. A sonication method was used to extract particles from ancient tissue. After extraction, individual ancient particles were isolated and examined for size and shape analysis using light microscopy. The surrogate particles were examined in the same manner. The particles were then imaged using environmental scanning electron microscopy (ESEM) and elemental profiles determined by energy dispersive X-ray analysis (EDAX). Bulk analysis by mass spectrometry was then employed to qualitatively and quantitatively analyse the elements contained within ancient lung particles and the modern surrogates. Electron probe micro-analysis (EPMA) was used to map the deposition and elemental composition of inorganic compounds in sections of ancient lung. Further information on the bonds and chain length of soots were obtained through FTIR and Raman spectroscopy.Results have shown the presence of anthracosis and birefringent particles in all ancient lung tissues examined by this study. Both organic and inorganic ancient particles have been found to be respirable (ie, less than 10 microns in diameter) and were present in the lung pre-mortem. EDX and ICP-MS results show the inorganic particles to consist of aluminium silicates (sand) and calcium carbonate (limestone). FTIR and Raman spectroscopy were not accurate enough to detect the ancient or surrogate soot bonds and were not suited to this study.