Institute of Occupation and Environment, Korea Workers' Compensation and Welfare Service, Incheon 21417, Korea.
Biomolecules. 2021 Mar 12;11(3):419. doi: 10.3390/biom11030419.
According to recent research, indium nanoparticles (NPs) are more toxic than micro-sized particles. While cases of indium lung disease have been reported worldwide, very little research has been conducted on the occupational exposure to indium NPs. Recently, an indium-related lung disease was reported in Korea, a global powerhouse for display manufacturing. In this study, we conducted an assessment ofoccupational exposure at an indium tin oxide (ITO) powder manufacturing plant, where the first case of indium lung disease in Korea occurred. Airborne dustwas obtained from a worker's breathing zone, and area sampling in the workplace environment was conducted using real-time monitoring devices. Personal samples were analyzed for the indium concentrations in total dust, respirable dust fraction, and NPs using personal NPs respiratory deposition samplers. The total indium concentration of the personal samples was lower than the threshold limit value recommended by the American Conference of Governmental Industrial Hygienists (ACGIH TLV), which was set as occupational exposure limit (OEL). However, the respirable indium concentration exceeded the recently set ACGIH TLV for the respirable fraction of indium dust. The concentration of indium NPs ranged between 0.003 and 0.010 × 10 mg/m, accounting for only 0.4% of the total and 2.7% of the respirable indium particles. This was attributed to the aggregating of NPs at the µm sub-level. Given the extremely low fraction of indium NPs in the total and respirable dust, the current OEL values, set as the total and respirable indium concentrations, do not holistically represent the occupational exposure to indium NPs or prevent health hazards. Therefore, it is necessary to set separate OEL values for indium NPs. This study covers only the process of handling ITO powder. Therefore, follow-up studies need to be conducted on other ITO sputtering target polishing and milling processes, which typically generate more airborne NPs, to further investigate the effects of indium on workers and facilitate the necessary implementation of indium-reducing technologies.
根据最近的研究，铟纳米粒子（NPs）比微尺度颗粒毒性更大。虽然全世界都有报道过铟肺病病例，但对职业性暴露于铟 NPs 的研究却很少。最近，韩国一家全球显示器制造强国报告了一例与铟有关的肺病。在这项研究中，我们对一家生产铟锡氧化物（ITO）粉末的工厂进行了职业暴露评估，韩国首例铟肺病病例就发生在这里。从工人的呼吸区采集空气粉尘，使用实时监测设备对工作场所环境进行区域采样。使用个人纳米颗粒呼吸沉积采样器对个人样本中的总粉尘、可呼吸粉尘部分和 NPs 中的铟浓度进行分析。个人样本中的总铟浓度低于美国政府工业卫生学家会议（ACGIH TLV）推荐的职业暴露限值（OEL），而可呼吸铟浓度超过了最近为铟粉尘可呼吸部分设定的 ACGIH TLV。铟 NPs 的浓度在 0.003 到 0.010×10mg/m 之间，仅占总铟和可呼吸铟颗粒的 0.4%和 2.7%。这归因于纳米颗粒在 µm 亚级别的聚集。考虑到总粉尘和可呼吸粉尘中铟 NPs 的比例极低，目前的 OEL 值（设定为总铟和可呼吸铟的浓度）并不能全面代表职业性暴露于铟 NPs 或预防健康危害。因此，有必要为铟 NPs 设定单独的 OEL 值。本研究仅涵盖处理 ITO 粉末的过程。因此，需要对其他 ITO 溅射靶抛光和铣削工艺进行后续研究，这些工艺通常会产生更多的空气传播 NPs，以进一步研究铟对工人的影响，并促进必要的铟减排技术的实施。
