1. Department of Nanofusion Technology, Hoseo University, Asan, Korea;
2. Occupational Lung Diseases Institute, Korea Workers’ Compensation and Welfare Service, Incheon, Korea;
3. Department of Mechanical Engineering, Hanyang University, Ansan, Korea;
4. HCTm, Co. Ltd., Icheon, Korea;
5. Institute for Risk Analysis and Risk Communication, University of Washington, Seattle, WA, USA;
6. Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA