1. Key Laboratory of Environment and Population Health of Liaoning Education Ministry (Shenyang Medical College), Shenyang, Liaoning Province, People's Republic of China
2. National Research Centre for The Working Environment, Lerso Parkalle, Copenhagen O, Denmark
3. Department of Thoracic Surgery, Liaoning Cancer Hospital, Shenyang, Liaoning Province, People's Republic of China
4. Department of Pathology, School of Basic Medical Sciences, Health Science Center, Peking University, Beijing, People's Republic of China