Plan to tighten air quality standards

BEIJING - The environmental authorities are proposing to strengthen the standards on air quality, which could lessen the number of official blue-sky days for many cities.

The new standards on air quality will include regulations on the monitoring and publication of particulate matter with a diameter of less than 2.5 microns (PM2.5), which are not currently included in determining the air pollution index (API), said Zhao Hualin, director of the pollution prevention department of the Ministry of Environmental Protection.

At present the API is derived from measurements of Sulfur Dioxide, Nitrogen Dioxide, PM10, Carbon Monoxide and Ozone, however, particulate matter finer than 10 microns has a far more harmful effect on human health than larger particles because they act as carriers of many pollutants.