- With Winter Ahead, Can China's Smog Get Anything But Worse? On Monday and Tuesday, air-quality monitoring stations in Harbin reported concentrations of PM 2.5 exceeding 1,000 micrograms per cubic meter - 40 times the limit deemed safe by the World Health Organization. http://sinosphere.blogs.nytimes.com/2013/10/24/with-winter-ahead-can-smog-get-anything-but-worse/?smid=re-share 19 comments worldnews