Figure 1From: Titanium dioxide nanoparticles: a review of current toxicological data Particulate distribution of TiO 2 particles by size through different regions of the respiratory tract. This diagram was derived from an explanation of particulate distribution after inhalation given by Simko and Mattsson [75]. Arrows represent downward movement of particles through the respiratory tract. Most particles in the size range of 1–5 nm are distributed throughout the three regions. 1 nm and 20 nm particles are mostly distributed in the nasopharyngeal region and alveolar regions respectively. 0.5-10 μm particles remain on the epithelial surface of the airways and alveoli.Back to article page