Detection of titanium particles in human liver and spleen and possible health implications

• Published in: Particle and fibre toxicology Vol. 15; no. 1; pp. 15 - 9
• Main Authors: Heringa, M B, Peters, R J B, Bleys, R L A W, van der Lee, M K, Tromp, P C, van Kesteren, P C E, van Eijkeren, J C H, Undas, A K, Oomen, A G, Bouwmeester, H
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 11.04.2018; BioMed Central; BMC
• Subjects: Aged; Aged, 80 and over; Autopsy; Female; Health aspects; Human liver; Human spleen; Humans; Limit of Detection; Liver - chemistry; Liver - ultrastructure; Liver diseases; Male; Microscopy, Electrochemical, Scanning; Middle Aged; Nanoparticle; Nanoparticles; Nanoparticles - analysis; Physiological aspects; Quantification; Risk Assessment; Risk factors; Sp-ICP-HRMS; Spectrometry, X-Ray Emission; Spleen - chemistry; Spleen - ultrastructure; Tissue Distribution; Tissue level; Titanium - analysis; Titanium dioxide; Human spleen; Sp-ICP-HRMS; Quantification; Nanoparticle; Risk assessment; Human liver; Tissue level; Titanium dioxide
• ISSN: 1743-8977; 1743-8977
• DOI: 10.1186/s12989-018-0251-7

Titanium dioxide (TiO ) is produced at high volumes and applied in many consumer and food products. Recent toxicokinetic modelling indicated the potential of TiO to accumulate in human liver and spleen upon daily oral exposure, which is not routinely investigated in chronic animal studies. A health risk from nanosized TiO particle consumption could not be excluded then. Here we show the first quantification of both total titanium (Ti) and TiO particles in 15 post-mortem human livers and spleens. These low-level analyses were enabled by the use of fully validated (single particle) inductively coupled plasma high resolution mass spectrometry ((sp)ICP-HRMS) detection methods for total Ti and TiO particles. The presence of TiO in the particles in tissues was confirmed by Scanning Electron Microscopy with energy dispersive X-ray spectrometry. These results prove that TiO particles are present in human liver and spleen, with ≥24% of nanosize (< 100 nm). The levels are below the doses regarded as safe in animals, but half are above the dose that is deemed safe for liver damage in humans when taking into account several commonly applied uncertainty factors. With these new and unique human data, we remain with the conclusion that health risks due to oral exposure to TiO cannot be excluded.