harbin

A traffic policeman signals to drivers during a smoggy day in Harbin, Heilongjiang province, October 21, 2013. The second day of heavy smog with a PM 2.5 index has forced the closure of schools and highways, exceeding 500 micrograms per cubic meter on Monday morning in downtown Harbin, according to Xinhua News Agency.

China Daily/Reuters

A traffic policeman signals to drivers during a smoggy day in Harbin, Heilongjiang Province. The second day of heavy smog forced the closure of schools and highways on Monday, according to Xinhua News Agency.