Source: IPE and Renmin University of China Law School, A Threat To Public Health: China’s Urban Air Quality Disclosure Needs Urgent Improvement: 2010 Annual Urban Air Quality Transparency Index (AQTI) Results and Comparative Study of 20 Domestic and 10 International Cities (19 January 2011), 32 .
See: http://www.ipe.org.cn/Upload/Report-AQTI-EN.pdf