Improved air monitoring network on way

Jiang Nan, an engineer at the Beijing Municipal Environmental Monitoring Center, will become busier after the capital doubles the number of monitoring stations in a bid to improve the network and step up efforts to curb pollution.

Beijing currently has 35 air quality monitoring stations, which measure major airborne pollutants including PM2.5 - particulate matter with a diameter less than 2.5 microns that is hazardous to health - and sulfur dioxide.

"We usually replace the core filter membranes at most every two weeks to guarantee the accuracy of measuring," Jiang said, adding that during severe smoggy days they replace them more frequently.