Massive pulmonary deposition of rutile after titanium dioxide exposure: Light-microscopical and physico-analytical methods in pigment identification.

Autopsy findings in a 55-year old man known to have been occupationally heavily exposed to titanium dioxide dust showed extensive pulmonary deposition of white pigment. By energy dispersive X-ray analysis (EDAX) and electron and X-ray diffraction, the pigment was identified as rutile. By ordinary transmitted light microscopy, deposits of the white crystalline titanium-dioxide could not be distinguished from anthracotic pigment present in the lung sections. By transmitted polarized and incident light microscopy, the different nature of the two types of pigment was immediately evident. Absence of inflammatory and fibrotic changes in the lungs in our case lends support to the view that rutile is biochemically inert.