China's environmental authorities are soliciting public opinions about the guidelines for the reporting of daily air quality index (AQI), which strengthen the standards on air quality assessment by adding measurements of Ozone, Carbon Monoxide and PM 2.5.

"The AQI is more demanding, but it won't make much difference to the number of blue-sky days in Hefei," Li Jing, deputy director of Hefei Environmental Monitoring Center said.

The Ministry of Environmental Protection is seeking to revise air quality standards largely because the current air pollution index (API), which is derived from measurements of Sulfur Dioxide, Nitrogen Dioxide and PM 10, fails to include particulate matter finer than 10 microns which is caused mostly by cars and coal burning and has a far more harmful effect on human health.

Compared with the API, the AQI includes measurements of Ozone, Carbon Monoxide and PM 2.5.

Bustling cities such as Beijing and Shanghai where PM 2.5 particulates account for much of the weight of industrial dust in the air will easily feel the effects of the new air quality assessment standards, while cities like Hefei, less industrialised and seeing fewer cars hitting the road, may not be clearly affected by the AQI, Li said.

"According to our real-time monitoring statistics, the daily PM 2.5 concentration averages 0.030 milligrams per cubic meter in Hefei. The figure is far below 0.075 milligrams per cubic meter, the dividing line between "excellent" and "lightly polluted" under the proposed AQI standards," Li said.