Until recently, news from China about its environmental concerns and problems were highly censored. But because it can no longer literally put a lid to control its spreading and unmanageable air pollution, China has admitted the smog haze situation in the country has already claimed thousands of lives.

In a commentary in Lancet published December 2013, Chen Zhu, China's Health minister, has finally and flatly given a number as to the death tally of the country's air pollution problem.

"Studies by the World Bank, WHO, and the Chinese Academy for Environmental Planning on the effect of air pollution on health concluded that between 350,000 and 500,000 people die prematurely each year as a result of outdoor air pollution in China," Mr Chen said in his commentary, which he co-wrote with Wang Jinnan, Ma Guoxia and Zhang Yanshen from the Ministry of Environmental Protection.

Until last year, Mr Chen was China's health minister.

At a time when the country's statistics on cigarette smoking is declining, deaths from air pollution was doing the opposite.

"When I see patients who are not smokers with no other risk factors, we have to assume that the most probable cause is pollution," Bai Chunxue from Shanghai's Zhongshan Hospital was quoted by Columbian News in December. Mr Bai is likewise chairman of the Shanghai Respiratory Research Institute.

Air pollution in China, according to Mr Chen, is now "the fourth biggest threat to the health of Chinese people" next to heart disease, dietary risk and smoking.

He also said China's leading cause of death is lung cancer.

In Beijing alone from 2002 and 2011 statistics of lung cancer deaths doubled, while in the last three decades deaths from lung cancer jumped 465 per cent all across the country.