Case reports of indium lung disease in Taiwan

The production of indium-tin oxide has increased in the past decades due to the increased manufacture of liquid crystal displays (LCD). Taiwan is one of the highest indium-consuming countries worldwide. After repeated inhalation, indium oxide (In₂O₃) particles would accumulate in the lungs, resulting in severe lung effects. We report two workers of an LCD producing facility with elevated serum indium level up to 149 and 73.8 μg/L (normal value <3.5 μg/L), which was much higher than that observed in previous case reports in Taiwan. We collected their detailed working history, symptoms, pulmonary function, radiologic findings, and followed up for more than one year. We also performed workplace evaluation of the facility. We observed that sandblasters who clean components of ITO thin-film production machinery by sandblasting with aluminum oxide tend to have higher indium exposure with worse pulmonary functions and HRCT findings.