Prospect of China's ambient air quality standards

Ambient air quality standards are the core strategic goal of ambient air quality management.Countries worldwide have given importance to research on the development of ambient air quality standards.To understand the history of the development of China’s ambient air quality standards,this study analyzed the background associated with all previous formulations and revisions of the standards,classification of functional areas,standard grading,pollutants,and evolution of the standard limits over the past 40 years.The results show that since the initial release of the“Ambient Air Quality Standard”by China in 1982,it has been supplemented once,revised twice,and modified twice.The first ambient air quality standard specified the standard limits of six pollutants commonly found in ambient air.With the development of ambient air quality management,the number of pollutants has increased to ten.Since the release of the“Ambient Air Quality Standards”in 2012,the ambient air quality in China has significantly improved.However,the proportion of cities meeting these standards is still low.At present,China is suitably positioned to make the standards associated with 24 hr SO2concentrations more stringent such that it meets the values defined in the World Health Organization(WHO)interim target-2 and the WHO air quality guideline(AQG).We further suggested that the SO2standard should be revised promptly.Simultaneously,regions with a relatively high proportion of cities meeting the standard are encouraged to introduce more stringent interim target limits in due course to manage the local ambient air quality.