Lung deposits in the 5300-year-old Tyrolean Iceman

M.A.Pabst+, F..Hofer*

+JInstitutfbr Histologie und Embryologic, Universitat Graz, A-8010 Graz, Austria * Forschungstitut fhr Elektronenmikroskopie,Techuische UniversitlitGraz, A-8010 Graz, Austria

In the Tyrolean &&al Alps alpinists discovered in 1991 a well-preserved, freeze-dried, Late Neolithic human mummy [l]. This male corpse is the oldest human mummy ever found. Lung material from this corpse was analyzed by a combination of different methods of analytical electron microscopy including energy-dispersive x-ray spectrometry (EDXS), electron energy-loss spectrometry (EELS), energy filtering TEM (EFTEM) and electron difiaction [2].

Lung sections from this mummy contain numerous anthracotic areas consisting of tine-grained particles (Fig.la). The carbon map showed that these particles are mainly rich in carbon (bright areas in Fig.lb); the EEL spectrum reveals that these particles consist entirely of carbon (Fig.lc). As the near edge fine structure of the C-K ion&&ion edge is typical for amorphous carbon we assume that they refer to soot particles which probably were inhaled from open fires in houses. Between these soot particles dif%erent tiny mineral crystals are seen. The bright regions in the Si-bs jump ratio image shown in Figure 2a correspond to the bright regions in the O-K jump ratio image (Fig.2b). Additional information of the composition of these crystals, seen in the EDX-spectrum (Fig2c) and information from an electron diffraction pattern showed that these and most of the crystals found in anthracotic areas refer to the mineral muscovite. The &z&l Alps, where the Iceman was found and where he probably lived, are composed of different muscovite-containing metamorphic rocks. Mica-rich rocks weather easily and so tiny crystals become airborne and may be inhaled. Beside muscovite feldspar crystals, illite and quartz particles were also found with the soot. Not only mineral particles were detected in the Iceman’s lung; some differently shaped amorphous particles were also inhaled and subsequently deposited in the anthracotic areas. These organic particles could derive from undigestible cell wall materials. Beside these findings two kinds of crystals were detected in the lung tissue outside of the anthracotic areas. One of them forms small aggregates (Fig.3a), which were identified as iron phosphate crystals (Fig.3c). The detailed analysis of the electron Faction pattern (Fig.3b) revealed that these crystals refer to vivianite. Vivianite has also crystallized in some areas on the surface of the Iceman’s skin [3] and there it were interpreted as formed on contact regions between the body surface and iron containing material. The second kind of crystal found outside of the anthracotic areas is hydroxyapatite. Calcium and phosphate were also detected by x-ray microanalysis of the Iceman’s skin [4]. As these two kinds of crystals are found separately in the lung tissue and as at least compounds of them are found on the skin of the mummy, we assume that they were not inhaled but were crystallized during the 5300 years of storage of the Tyrolean Iceman in the high mountains.

References

1. Henn R, The man in the ice, (edited by F. Hopfel, W. Platzer, K. Spindler) Vol.1, p.88 Publication of the University of Innsbruck (1992) 2. Hofer F. and Pabst M.A. Micron in press (1998) 3.Tiefenbrunner F., XJzeman in the ice, (edited by F. Hiipfel, W. Platzer, K. Spindler) Vol.1, p.100 Publication of the University of Innsbruck (1992) 4. Van der Velden E. et al., The man in the ice (edited by K. Spindler, E.Rastbichler-Zissernig,H. Wilting, D. zur Nedden, H. Nothdurfter) Vo1.2,p.275, Springer, Wien (1995). 300 400 500 Energy-Loss (eV)

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200 400 500 Energy-loss (eV)

Fig& TEM image of an anthracotic area, lb: C-K elemental map ofthii area, lc: EEL-spectnun of soot particles and embedding tissue (dashed) Fig.2a: Si-h jump ratio image of an anthracotic region, 2b: O-K jump ratio image of the same region, 2c: EDX-spectrum of a muscovite particle. Fig.3a: TEM image of vivianite crystals, 3b: electron diffraction pattern of such a crystal, 3~: EELspectrum of vivianite particle. P- b3 edge is also shown with the background subtracted.