Study Links Indium in Workplace Air with Lung Disease

A study conducted by researchers from NIOSH and colleagues has found that workers making and reclaiming indium-tin oxide (ITO), which is used to make products that include flat-panel displays, touch screens, solar panels, and energy-efficient windows, are at risk for indium lung disease.

The study by K.J. Cummings, et al. from NIOSH, the Institute of Health and Environment at Seoul National University (Korea), the Translational Pulmonary Science Center at Cincinnati Children’s Hospital Medical Center, and the Division of Pulmonary, Critical Care, and Sleep Medicine at the University of Cincinnati College of Medicine was published in the American Journal of Industrial Medicine and highlighted this month by NIOSH in its Research Rounds bulletin.

Studies describe this as a serious and potentially fatal condition that can progress from early filling of the lung’s air sacs with fluid to later lung scarring and emphysema. Indium can be detected in the blood of ITO workers, and workers with higher concentrations of indium in the blood appear to be at greater risk.

However, the precise relationship between the level of exposure to airborne indium compounds and risk of indium lung disease is unclear. For one thing, scientific evidence needed to relate workplace air concentrations of indium with concentrations in the blood of exposed workers has been lacking.

They recently found a correlation between the amount of indium in the workplace air and early signs of lung disease among a group of ITO workers, as reported in the peer-reviewed American Journal of Industrial Medicine.

In addition, the workers exposed to respirable indium for nearly 2 or more years had more shortness of breath, lower lung function, and higher levels of markers in the blood for lung damage than did workers with fewer than 2 years of exposure. In other findings, the study showed that those health effects occurred among workers in the study group who had relatively low levels of exposure to indium in the air.

Further studies of other groups of ITO workers with longer and different types of work-related exposure to indium are important to confirm this study’s findings. Even so, the findings support precautionary efforts to reduce work-related exposure to respirable indium, according to the authors.