TIANJIN, Jan. 21 -- A series of unprecedented measures implemented last year to curb air pollution in north China's Tianjin Municipality were lauded a success.

The city, which is 150 kilometers southeast of Beijing, reported 175 days of excellent or good air quality (AQI between 0-100) in 2014. This is an increase of 30 days from 2013, said Wen Wurui, director of the city's environment bureau.

The city's density of PM2.5 and PM10, two key air pollution indicators, dropped by 13.5 percent and 11.3 percent respectively, he said.

A total of 115 coal-fired boilers were dismantled or converted to gas and 143,000 old cars were scrapped.

In addition, local authorities also issued tougher regulations on prevention and control systems, such as increasing the fees heavy-polluting factories must pay by ten times the previous level.

Smog and haze has fueled discontent among urban residents nationwide, prompting the authorities to take the issue very seriously.