Xi'an, original name as Chang'an, ancient capital of China's first empire and following twelve dynasties, was infamous among millions of tourists flocking to the Terracotta Warriors or the Muslim Quarter. Now, thanks to efforts by the environment watchdog, blue skies have returned once more to the capital of Shaanxi.

From this January to July, Xi'an enjoyed 181 days of "good weather", close to a week more than the same period in 2006, announced Ren Yongfeng, vice director of the Xi'an Environment Protection Administration, at a press conference on August 29.
 
"Good weather" means that the quality of a city's air has reached or above level II of the national standards.
 
By August 24, the city had recorded 204 days of good weather, occupying 86.4 percent of all days past this year, Ren told China.org.cn.
 
In 2006, the city recorded 289 days of good weather, accounting for 79.18 percent of days. The content of sulfur dioxide and nitrogen dioxide stood below the national standards for level II air quality. The annual average content of sulfur dioxide stood at 0.055 milligram per cubic meter with nitrogen dioxide at 0.042 milligram, but the particulate matter content registered slightly over the level II standard, at 0.132 milligram per cubic meter.
 
Before, the air quality of Xi'an was notorious among its millions of incoming tourists due to "the loose management of enterprises' pollution limits due to the pursuit of economic growth in the 1980s and 1990s. Xi'an only recorded 175 days at level II in 2002," said Ren.
 
No air quality monitor device was present in Xi'an until 2002 which marked a turning point. 
 
"Thanks to many efforts in the following years, the city has recorded more days of good weather, with 290 days in 2005." 
 
In recent years, 5,320 minor coal-fired boilers were dismantled in Xi'an. Besides, 6.906 restaurants in urban districts have been ordered to add devices to cut down soot and lampblack.
 
Stricter measures have been also leveraged to supervise the tail gases of the city's 650,000 cars. Statistics shows that 8,948 drivers were punished for violation of tail gas limit. To cut down car pollution, the municipal government began promoting natural gas as fuel years ago, with 61 natural gas filling stations established city-wide at the end of 2006.

(China.org.cn by Wang Zhiyong, August 30, 2007)