BEIJING â€"  Beijing authorities have completed a network of monitors to better measure air pollution. They have been pushed into the move by public pressure and air quality readings from the U.S. embassy.

The Beijing Municipal Environmental Monitoring Center said another 15 monitoring stations began releasing real-time data on small particulates on Saturday. The tiny particles can penetrate deep into the lungs, damaging them.

Pressure has built on the government since the U.S. Embassy started publishing air quality readings on Twitter. Chinese citizens have prodded their government into publishing more detailed pollution data.

Beijing started releasing data on the small particulates, known as PM2.5, in January. It now has 35 monitoring stations running on a three-month trial. Then the city's environmental protection department will formally use PM2.5 to evaluate air quality.