Real time, stricter air monitoring service launched

Nov 16 | Source: Hangzhou Daily/Edited by Shanghai Daily

LOCAL residents will be receiving more accurate and timely air pollution updates after a stricter air quality criterion was put into use today in Hangzhou and in neighboring Shanghai and Jiangsu Provinces.

As of 12am, local environment authorities' websites started releasing the daily and hourly air quality index or AQI, while the media will report AQI every day to inform the public of the quality of the air they breathe.

The new index is based on six indicators: PM10, sulfur dioxide, carbon dioxide, PM2.5, ozone and carbon monoxide levels. The previous air pollution index or API used only three indicators: PM10, sulfur dioxide and carbon dioxide. PM2.5 is a measure of airborne pollutants smaller than 2.5 microns in diameter, which are the main cause of urban smog.

Real-time air quality information is available online at, including daily and hourly readings and a chart of the six indicators.

AQI and each indicator are shown across six levels, with each level given a different color. They range from green, which is excellent, to maroon, which is severely polluted.

In the new system, the daily index of air quality under AQI is evaluated over 24 hours from the previous midnight, while API is from the previous noon.

The nation's average daily limit of PM2.5 is 75 micrograms per cubic meter. The bureau and education officials will require schools to reschedule outdoor activities on severely polluted days.

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