Abstract: National standards have adopted rich experience of developed countries and regions in initiation of ambient air quality and standards. The World Health Organization (WHO) standing from health perception, provides standards and judgments according to existing scientific research, and also serves as the standard basis and reference, the up-to date guidance limit adjusted by WHO in 2021 has been recorded and analyzed. Summarizes the impact of air pollutants on health, and introduces WHO standards and limit requirements for ambient air quality. Comprises four parts: histories of standards, air quality classification, types of controlled pollutants, standard limits, monitoring and detection methods, in comparison with ambient air quality of different countries, the theory fundamental basis and value evidence has been discussed, standing on the prior art GB/T 18883 “Indoor air quality” it provides a reference for the formulation of indoor air quality standards for home scenes in China.

Key words: Environment air quality, Air quality standards of home scenes, Limit requirements of pollutants