[Zhou, Zhou; Pei, Li-ping; Li, Min; Gao, Peng; Mei, Xiang; Zhang, Lei; Yu, Zheng-ping; Pi, Hui-feng; Lu, Yong-hui; Zhang, Zhao-hui] Third Mil Med Univ, Dept Occupat Hlth, Chongqing 400038, Peoples R China.
[Liu, Lin] Third Mil Med Univ, Dept Med Stat, Chongqing, Peoples R China.
[Zhao, Qi] Ctr Dis Control Chongqing, Dept Occupat Hlth, Chongqing, Peoples R China.
[Chen, Yu; Qin, Qi-Zhong] Chongqing Med Univ, Fac Prevent Med, Dept Environm Hlth, Chongqing, Peoples R China.
[Jiang, Yue-ming] Guangxin Med Univ, Dept Occupat Hlth, Coll Publ Hlth, Nanning, Peoples R China.