[1] China Med Univ, Sch Publ Hlth, Dept Biostat & Epidemiol, Shenyang, Peoples R China
[2] St Louis Univ, Sch Publ Hlth, Dept Epidemiol, St Louis, MO 63104 USA
[3] St Louis Univ, Sch Publ Hlth, Dept Biostat, St Louis, MO 63104 USA
[4] Shenyang Environm Monitoring Ctr, Dept Ambient Air Pollut Monitoring, Shenyang, Peoples R China
[5] Sun Yat Sen Univ, Sch Publ Hlth, Dept Epidemiol, Guangzhou 510275, Guangdong, Peoples R China
[6] St Louis Univ, Sch Publ Hlth, Dept Environm & Occupat Hlth, St Louis, MO 63104 USA