China National Environment Monitor Center (CNEMC) workers inspect PM2.5 - airborne pollutants smaller than 2.5 microns in diameter - monitoring equipment in Beijing on Jan 4, 2012. [File photo]

A network to monitor PM2.5 in the air in the Chinese capital was completed Saturday as another 15 monitoring stations began releasing real-time data.

The network, which is composed of 35 PM2.5 monitoring stations, will publish the air quality data online, according to the Beijing Environment Monitoring Center.

The PM2.5 air quality standard monitors fine particles with a diameter of 2.5 microns or less. It is considered more hazardous to people's health as it can go deeper into the lungs. But PM2.5 monitoring was not included in China's air quality monitoring before.

The monitoring network will undergo a trial operation for three months, before the city's environmental protection department formally adopts the data in 2013 as new measures to evaluate the air quality of the city.

The Ministry of Environmental Protection has ordered 74 cities to apply a more comprehensive air quality monitoring standard and publish daily reports on PM2.5 by the end of this year.