According to a joint study by Chinese and Western scholars from the Massachusetts Institute of Technology, Tsinghua University, Beijing University, and a professor at the Hebrew University of Israel, severe air pollution in northern China reduces the average life expectancy by at least 5.5 years. However, in an interview with BBC Chinese, Professor Song Yuqin from Beijing University’s School of Environmental Science and Engineering expressed his doubts about the “5.5 years life expectancy reduction” conclusion. “You do not need to take it (the conclusion) seriously.” In Prof. Song’s opinion, it is unlikely that smog could be eliminated in 20 to 30 years because China is in the process of development. He did, however, call on the government to take action because "the root cause still lies with the government."
Source: BBC Chinese, July 10, 2013
http://www.bbc.co.uk/zhongwen/simp/china/2013/07/130710_china_environment_south_north.shtml