Open AccessTwo‐ and 13‐week Inhalation Toxicities of Indium‐tin Oxide and Indium Oxide in Rats
Author(s) -
Nagano Kasuke,
Gotoh Kaoru,
Kasai Tatsuya,
Aiso Shigetoshi,
Nishizawa Tomoshi,
Ohnishi Makoto,
Ikawa Naoki,
Eitaki Yoko,
Yamada Kenichi,
Arito Heihachiro,
Fukushima Shoji
Publication year - 2011
Publication title -
journal of occupational health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 59
ISSN - 1348-9585
DOI - 10.1539/joh.l10128
Subject(s) - inhalation , pulmonary alveolar proteinosis , medicine , lung , indium tin oxide , indium , pathology , alveolar macrophage , inhalation exposure , chemistry , anesthesia , macrophage , biochemistry , in vitro , organic chemistry , layer (electronics)
Two‐ and 13‐week Inhalation Toxicities of Indium‐tin Oxide and Indium Oxide in Rats: Kasuke Nagano, et al. Japan Bioassay Research Center, Japan Industrial Safety and Health Association—Objectives Two‐ and 13‐week inhalation toxicities of indium‐tin oxide (ITO) and indium oxide (IO) were characterized for risk assessments of workers exposed to ITO. Methods F344 rats of both sexes were exposed by inhalation to ITO or IO aerosol for 6 h/day, 5 day/wk for 2 wk at 0, 0.1, 1, 10 or 100 mg/m 3 or 13 wk at 0, 0.1or 1 mg/m 3 . An aerosol generator and inhalation exposure system was constructed. Results Blood and lung contents of indium were elevated in a dose‐related manner in the ITO‐ and IO‐exposed rats. ITO and IO particles were deposited in the lung, mediastinal lymph node and nasal‐associated lymphoid tissue. Exposures to ITO and IO induced alveolar proteinosis, iniltrations of alveolar macrophages and inlammatory cells and alveolar epithelial hyperplasia in addition to increased lung weight. ITO affected the lung more severely than IO did. Fibrosis of alveolar wall developed and some of these lesions worsened at the end of the 26‐week post‐exposure period. Conclusions Persistent pulmonary lesions including alveolar proteinosis and macrophage iniltration occurred after 2‐ and 13‐week inhalation exposures of rats to ITO and IO. Fibrosis of alveolar wall developed later. These lesions occurred after ITO exposure at the same concentration as the current occupational exposure limit in the USA and at blood indium levels below the biological exposure index in Japan for indium.