1. Faculty of Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba
2. Environmental Epidemiology Section, Center for Environmental Health Sciences, National Institute for Environmental Studies
3. Department of Health and Welfare, Ibaraki Prefectural Office
4. Department of Public Health, Dokkyo Medical University School of Medicine
5. Ibaraki Health Plaza, Ibaraki Health Service Association
6. Ibaraki Health Service Association
7. Public Health, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University