1. Department of Environmental MedicineKochi Medical School, Kochi UniversityJapan
2. Department of Preventive and Social Medicine, Faculty of Medicine Siriraj HospitalMahidol UniversityThailand
3. Clinical Trial Center, Kochi Medical School, Kochi UniversityJapan
4. Section for Clinical Epidemiology and Biostatistics, Faculty of Medicine Ramathibodi HospitalMahidol UniversityThailand
5. Department of Occupational MedicineKinro ClinicJapan
6. Department of RadiologyKochi Medical School, Kochi UniversityJapan