1. Department of Epidemiology and Health Statistics, School of Public Health Fujian Medical University Fuzhou China
2. Key Laboratory of Ministry of Education for Gastrointestinal Cancer Fujian Medical University Fuzhou China
3. Department of Oral and Maxillofacial Surgery The First Affiliated Hospital of Fujian Medical University Fuzhou China
4. Laboratory Center, The Major Subject of Environment and Health of Fujian Key Universities, School of Public Health Fujian Medical University Fuzhou China