Interstitial pneumonia developed in a worker dealing with particles containing indium-tin oxide.

The use of indium compounds in the electronics and semiconductor industry has risen sharply from the 1990s, and indium demand increased to a record 335 tons in 2000 in Japan, which was about 5 times that in 1990. Indium-tin oxide (ITO) is a sintered alloy containing a large portion of indium oxide and a small portion of tin oxide, and is used in the making of thin-film transistor liquid crystal displays (LCDs) for television screens, portable computer screens, cell phone displays and video monitors. Japan was the world’s largest consumer of indium, with three-fourths of it going for ITO coatings in 2000. More than one-half of the world’s indium consumption is for ITO coatings. Due to the increasingly frequent industrial use of ITO, the potential occupational exposure to this material has attracted much attention. Although there are no available data about the potential of ITO to induce lung damage in humans, pulmonary and testicular toxicity was reported recently when ITO was given to hamsters in intermittent intratracheal instillations . This is the first case history to our knowledge describing a man with interstitial pneumonia consistent with the inhalation of ITO particles.