[1] Okayama Univ, Dept Epidemiol, Grad Sch, Okayama 7008530, Japan
[2] Harvard Univ, Sch Publ Hlth, Dept Environm Hlth, Boston, MA 02115 USA
[3] Okayama Univ, Grad Sch, Dept Environm Epidemiol, Okayama 7008530, Japan
[4] Hirano Kameido Himawari Clin, Tokyo, Japan
[5] Gifu Environm Med Res Inst, Gifu, Japan