BEIJING, Dec. 7 -- As hazardous air pollution forced schools to close in the city of Nanjing on Friday, Xiang Lili, a university teacher, had to ask for leave to take care of her 4-year-old son.

The Nanjing government issued a "red alert" for air pollution as pollution-filled smog continued to shroud eastern China for the fifth straight day.

In Shanghai, PM 2.5, or particulate matter with a diameter of less than 2.5 micrometers, reached a staggering reading of 602.5. In the city's Lujiazui area, China's financial center, pedestrians covered their faces with thick masks. Social networking websites and applications were awash with tips for living through the smog crisis.

"If the government cannot reverse the poor air quality, I will be really disappointed, or even desperate about our society," Xiang said.

Officials and activists say the bad environment has become a thorny issue in relations between Communist Party cadres and the masses.

Since skyrocketing economic growth usually ensures a fast track for promotion, Chinese officials scramble for heavy industry projects that draw huge investment, and they often do so at the cost of the environment.

"The heavy smog outside is a wake-up call for everybody," said Gao Wenxue, deputy director of the environment protection bureau in the city of Huai'an, Jiangsu Province.

"If we can't resolve the environmental problems, there will be significant impacts on cadre-masses relations and even on social stability," Gao said.

President Xi Jinping promised to shake off GDP obsession in promoting officials.

President Xi has called for comprehensive efforts to prevent and curb pollution, urging focus on areas surrounding rivers and lakes as well as major air-polluting industries.

Stressing that only "the strictest system and tightest law enforcement" can ensure China's ecological construction, Xi urged a responsibility-pursuing mechanism targeting those behind irresponsible decision-making that leads to severe environmental consequences.

The State Council, or China's cabinet, outlined ten measures in June for curbing the air pollution that is plaguing the country, vowing "tough measures for tough tasks."

The government should incorporate optimizing the country's economic structure and intensifying innovation in its environmental protection efforts, the State Council announced.

The State Council promised to strictly control high energy-consuming and polluting industries, adjust energy structure and enhance control of

PM 2.5 in populated regions and metropolises.

It set a goal of reducing key industries' emissions of major air pollutants by at least 30 percent by the end of 2017.

According to environmental protection officials, it used to be common practice to put monitors at places that could result in better readings, but this type of falsification became less common this year.

"Curbing air pollution is a complicated and systematic project that requires long and arduous effort," the cabinet noted in a statement.