Key contribution

Neighboring regions have also made a significant contribution to the improved air quality in Beijing.

He Kebin, a professor at Tsinghua University's School of Environment and an academician at the Chinese Academy of Engineering, said emission reduction efforts in nearby areas, especially Hebei province and Tianjin, have been important in improving air quality in the capital.

For the past five years, Beijing, Tianjin and Hebei have coordinated efforts to prevent air pollution.

A scientific evaluation was carried out to assess the contribution made by regions neighboring Beijing in reducing emissions, He Kebin said. This work was supported by a series of important scientific research projects from the Ministry of Science and Technology, the Ministry of Ecology and Environment, and the National Natural Science Foundation of China.

The evaluation results showed that from 2013 to last year, surrounding areas contributed to a PM2.5 reduction of 14.4 mcg per cu m in Beijing.

He Kebin said Tianjin and Shanxi, Hebei, Henan and Shandong provinces contributed a PM2.5 reduction of 7.1 mcg per cu m in Beijing, accounting for 22.5 percent of the overall such reduction in the capital from 2013 to 2017.

"Generally speaking, the surrounding areas contribute about 25 to 30 percent to Beijing's air quality improvement," he said. "As the city's air quality is already at a relatively good level, regional integrated control and prevention measures for better air will play an essential role in the future," He Kebin added.

Meanwhile, science and technology have also played a vital role. Beijing was the first city in China to establish an urban air quality prediction system, which can accurately analyze sources of PM2.5 and its transmissions. The system has provided a scientific foundation for control and prevention work.

As people have become used to clear skies and fresh air in Beijing, the municipal government said efforts will continue this year to ensure good air quality for the public.