Binding of metals in dacryoliths by means of biomineralization.


National Research Tomsk State University, 36, Lenin Avenue, Tomsk, 634050, Russia. Electronic address: [Email]


Dacryoliths are organomineral aggregates released from human lacrimal ducts, and are known to include a 1 to 3 % (by volume) of a mineral (inorganic) component This study was based on a collection of approximately 800 dacryoliths collected from a patient in Siberia. The shapes and sizes of mineral grains, their composition and their distribution in the organic matrix are very diverse; our detailed investigation identifies a number of inorganic phases that were not previously recognized. These were imaged on a scanning electron microscope (Tescan VEGA II LMU), and the chemical composition of the inorganic component was determined by energy dispersive X-Ray spectroscopy (INCA Energy350, Oxford Instrument), and X-ray analysis (X-ray diffractometer XPert PRO (PANalytical). For the first time, we identified the following minerals which can be divided into three groups: 1) oxide Si, pyrite, calcium oxalate, barite, which are often present in the tissues of the living organism and are also known in geological processes; 2) abundant complex mineral phases, consisting of Al, Si, K and Ti or Fe (titanium and iron aluminosilicates), which are also present in organism but have no analogues in the abiogenic environment; and 3) oxygen-containing compounds of Ni and Pb-Cr (possibly nickel oxide and lead chromate, respectively) which are only found in the abiogenic environment. Those mineral phases of biogenic origin are due to an endogenous (pathological) process in the body caused by internal factors (hypoergosis and metabolic disorders). This biomineralization may have a role in the removal of toxic and / or excess ions of Fe, Ti, Cr, Pb, Ni, Al, and Si from tissues.


Biomineralization,Composition,Dacryolith,Dry Eye Syndrome,SEM/EDS,XRD,

OUR Recent Articles