[1] Saitama Med Univ, Dept Resp Med, Saitama, Japan
[2] Kyoto Univ, Grad Sch Med, Dept Resp Med, Kyoto, Japan
[3] Tohoku Univ, Ctr Environm Conservat & Res Safety, Sch Med, Sendai, Japan
[4] Tohoku Univ, Sch Med, Dept Occupat Hlth, Sendai, Japan
[5] Yamaguchi Univ, Grad Sch Med, Dept Resp Med & Infect Dis, Ube, Japan
[6] Hokkaido Univ, Fac Med, Dept Resp Med, Sapporo, Japan
[7] Nara Med Univ, Dept Resp Med, Nara, Japan
[8] Keio Univ, Sch Med, Dept Med, Div Pulm Med, Tokyo, Japan
[9] Shiga Univ Med Sci, Dept Internal Med, Div Resp Med, Otsu, Japan
[10] Tokai Univ, Tokyo Hosp, Dept Med, Div Pulm Med, Tokyo, Japan
[11] Shinshu Univ, Sch Med, Dept Internal Med 1, Matsumoto, Japan
[12] Saitama Med Univ, Dept Resp Med, 38 Morohongo,Moroyama Machi, Saitama 3500495, Japan