1 Department of Environmental and Occupational Health, National Cheng Kung University, Tainan 704, Taiwan ; Department of Occupational and Environmental Medicine, National Cheng Kung University Hospital, Tainan 704, Taiwan.
2 Department of Environmental and Occupational Health, Universiti Putra Malaysia, 43400 Selangor, Malaysia.
3 Department of Occupational Medicine, Chi-Mei Medical Center, Tainan 710, Taiwan.
4 Deputy Vice-Chancellor's Office (Research and Innovation), Research and Innovation and Academic Division and Faculty of Health, Engineering and Sciences, University of Southern Queensland, Toowoomba, QLD 4350, Australia.