1. Department of Toxicology, College of Public Health Zhengzhou University Zhengzhou Henan China
2. College of Public Health University of Southern California Los Angeles California USA
3. Key Laboratory of Tobacco Chemistry Zhengzhou Tobacco Research Institute, CNC Zhengzhou Henan China
4. Department of Disease Control and Prevention Hospital of Zhengzhou University Zhengzhou Henan China
5. Department of Pulmonary Medicine The First Affiliated Hospital of Zhengzhou University Zhengzhou Henan China