1. Yangzhou Center for Disease Prevention and Control, Yangzhou, Jiangsu, People's Republic of China
2. Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
3. Kunshan Center for Disease Prevention and Control, Suzhou, Jiangsu, People's Republic of China
4. Institute of Occupational Disease Prevention, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu, People's Republic of China