Air Quality Index to show less hazy pollution reading

The Shanghai Environmental Monitoring Center will soon begin releasing unvarnished hourly readings of the city's Air Quality Index (AQI), the local environmental protection bureau said Monday.

The hourly AQI readings will more closely resemble the levels of air pollution that residents experience at any given time, said Tian Jin, a press officer with the Shanghai Environmental Protection Bureau.

The AQI is currently updated every hour, but as an average of the previous 24 hourly readings, according to a news report on Shanghai Television Station.

The 24-hour average can be misleading because it conceals sharp rises and drops in the AQI over the short term, the report said.

For example, the AQI stood at 149 at 9 am Monday, indicating a light level of pollution, the report said.

However, the reading for PM 2.5, the primary pollutant affecting the index, was 148 micrograms per cubic meter, or about four times the national standard, indicating heavy pollution.

The environmental protection bureau has not released when the monitoring center will make the change, Tian told the Global Times.