1 1 Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China ; 2 Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China ; 3 The Jockey Club School of Public Health and Primary Care, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin-NT, Hong Kong Special Administrative Region, China ; 4 Shenzhen Municipal Key Laboratory for Health Risk Analysis, Shenzhen Research Institute of the Chinese University of Hong Kong, Shenzhen, China.