1. Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District; Tianjin 300011 People's Republic of China
2. School of Public Health; Tianjin Medical University, 22 Qixiangtai Road, HepingDistrict; Tianjin 300070 People's Republic of China
3. Tianjin Municipal Inspection Bureau for Health and Family Planning, 94 Guizhou Road, Heping District; Tianjin 300070 People's Republic of China
4. Department of Quality Control; The First Affiliated Hospital of Zhejiang University, School of Medcine; Hangzhou Zhejiang China
5. Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health; Tongji Medical College, Huazhong Universityof Science and Technology, 13 Hangkong Road; Hubei Wuhan 430030 People's Republic of China