Shanghai's air quality index reporting system was due to be updated on Friday by the city's Environmental Protection Bureau to provide real-time information to the public.

The previous reporting system, implemented in November, was criticised for failing to provide real-time air quality index readings when air quality changed suddenly.

Under the new system, if there is a sudden air quality change, a more specific description will be provided, the bureau said.

For instance, readings of real-time PM 2.5 - hazardous particulate matter of 2.5 micrometers in diameter or less that can penetrate the lungs - will be provided in real time, along with protection suggestions.

When people log on to the new air quality monitoring system, they will find a real-time photo taken from the Bund, changes in real-time concentration of air pollutants and changes to the air quality index over 24 hours and seven days.

The changes will appear on the website of the Shanghai Environmental Monitoring Center, the micro blog of the Shanghai Environmental Protection Bureau and applications installed on mobile devices.