1. Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Shuang Yong Road 22, Nanning, Guangxi 530021, China
2. Guangxi Colleges and Universities Key Laboratory of Prevention and Control of Highly Prevalent Diseases, Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi 530021, China