It was with some reluctance that Ma Xiaobing upgraded his kebab stall by investing in a smoke control device, but he is doing much better business now.
"In the past, we roasted four legs of lamb each day. Currently, we need about 20 a day," said Ma of Lanzhou, Gansu Province. "There are more diners and we are busier than ever."
Lanzhou, a city in the Yellow River valley in the country's arid northwest, was once among China's most polluted cities. Pollution was so bad that people even joked that the town did not show up on satellite images.
Strong pollution control measures have lowered PM10 and PM2.5 densities in the city to less than 75 percent of 2013 levels. Last year, the annual number of blue sky days increased by 50 to reach 243.
The provincial capital has become "a model of air quality improvement," according to a central inspection team. Annual coal consumption in the city has been reduced from 10 million tonnes in 2012 to around six million tonnes last year.
One of the things Lanzhou has done is to rally grassroots officials into the battle. Yang Mingyan, a subdistrict office clerk, is one of the 10,000 pollution supervisors in the city.
"Every morning, I check the area I am responsible for to see who is burning what, and whether substandard coal or wood are being used. If I find a problem, I will ask whoever is responsible to stop. If they will not listen to me, I report the matter to superior authorities."
All cities have anti-pollution policies, but in Lanzhou these policies are very strictly imposed.
"Some cities are afraid or unable to deal with big companies in environmental protection for fear it will affect their economy, but Lanzhou has no such problem," said Xing Lifeng, deputy director of Lanzhou environmental protection bureau.
The bureau even fined a leading state-owned petrochemical enterprise and has asked some companies to apologize to citizens.
Some officials were punished for failing to properly apply themselves to their pollution control duties while others who showed more enthusiasm were promoted.
"In fact, many of our measures are not very innovative, but in Lanzhou polluters are subject to the full force of the law." said Xing.
Some heavily polluted cities, such as Shijiazhuang and Zhengzhou, have sent officials to Lanzhou to study its experiences first hand.
Many of Lanzhou's successes could easily be transplanted to other places, said Ma Jianmin of Lanzhou University.
For example, online monitoring data is all well and good, but it is standard practice in Lanzhou for personnel to actually visit big polluters and see for themselves exactly what is going on, he said.
The government expects good air quality days to account for more than 80 percent in all cities at prefectural level and above by 2020. It's an ambitious target, and one that has not been met yet in Lanzhou.
"Lanzhou still has some way to go to meet the goal. Pollution decreases initially by dealing with that which is easiest to control. Pollution control is therefore increasingly difficult and our work becomes harder with every success," said Chen Yimin, a Lanzhou environmental official.
