Air pollution is a perennial headache in China, with its industrialized Yangtze and Zhujiang river deltas and the area around Beijing being the hardest hit. But after a hazy 2013, alarm bells are ringing in areas where air pollution was previously moderate.

Neither Guangxi nor Hubei is in the traditional "smog belt," and in 2013, several provinces and cities known for their good air quality also reported unusual outbreaks of smog, including the southeastern province of Fujian and Lhasa city in Southwest China's Tibet autonomous region.

Apart from unfavorable weather patterns, experts have blamed unchecked industrial pollution and the side effects of rapid urbanization for the appearance of smog in more Chinese areas.

In the case of Guangxi, the increased discharge of industrial emissions, dust from construction sites and vehicle exhaust are identified as factors behind the deteriorating air quality, said Yu Zebin, an environmental expert at Guangxi University.

"The city of Nanning, for instance, is busy building its subway system and urban facilities, so construction sites are everywhere in the city. Meanwhile, huge and rapidly growing car ownership is also causing more exhaust to be emitted into the air," Yu said.

Political advisors and analysts in Guangxi and Hubei have proposed measures ranging from tightened controls on industrial polluters to promoting public transportation.

Regional cooperation was also highlighted in a proposal by the Hubei commission of the China Democratic League, which urged for joint efforts by all cities in the smog-hit area.

Yet Li Hong said she did not expect the problem to be solved in a short time.

"Tackling smog requires a systematic approach that involves economic restructuring and industrial upgrading. We should prepare for a long battle," Li said.