LHASA -?China's Tibet autonomous region will launch an air quality index next year to better monitor change in air quality, the regional environmental bureau said Wednesday.

By the end of November, 18 automatic air monitoring stations were set up in 7 prefecture-level regions in Tibet. Their real-time data collection has been connected to the national environmental monitoring network, Jambai, head of the regional environmental bureau, said.

The stations can help track air pollutants such as sulfur dioxide, nitrogen dioxide, ozone content and small particulate known as PM2.5.

"The launch of Tibet's air quality index will enable public supervision on environmental protection work in the region," he said.

Seated on the world's highest plateau region, Tibet boasts some of the freshest air in the world. However, in recent years, meteorologists have observed smog in the regional capital of Lhasa.

A heavy cloud of dust grounded flights last winter. The images of the world-famous Potala Palace in Lhasa being cloaked by smog were posted on the Internet, causing a public concern on the air quality changes in the region, believed as one of the world's remaining pollution-free area.