Beijing’s government last Friday bowed to a vocal online campaign for a change in the way air quality is measured in the Chinese capital, one of the world’s most polluted cities.

Authorities said they would start publishing figures this month showing the smallest, most dangerous pollution particles in the air after considering the wishes of residents, expressed on China’s popular microblogs.

The Chinese capital currently bases its air quality information on particles of 10 micrometers or larger, known as PM10, and does not take into account the smaller particulates that experts say are most harmful to human health.

But authorities came under huge pressure to change the system last year when they ranked the air as only slightly polluted, despite thick smog that forced the cancellation of hundreds of flights and triggered a surge in face mask sales. The local government already measures particles of 2.5 micrometers or less, known as PM2.5, but China’s environment ministry had said the data would not be available nationwide until 2016.

On Friday the Beijing Environmental Bureau said it would provide hourly updates of PM2.5 measure ahead of the Lunar New Year, or Spring Festival, which starts on January 23, in response to the flood of public anger.

“The authorities plan to release air-quality monitoring data using PM2.5 before Spring Festival,” a bureau official told AFP.

“The government has to consider the pleas of the people, so yes, the anger of Beijing citizens these days is a big contributor to our action.”

Public anger was exacerbated by the discrepancy between the official data and that issued online and on Twitter by the US embassy in Beijing, which conducts its own measures of PM2.5 and frequently registers dangerous pollution levels.