Authorities issue warning as smog engulfs Beijing
STORY: Beijing said on Tuesday (October 31) it would implement traffic control measures if the capital activated its highest air pollution warning.
Experts said weak cold air currents from the north pole were a key factor behind the unusual weather.
As air pollution levels in the wider Beijing-Tianjin-Hebei area and northern part of Henan province reached moderate to severe, pollution control experts said increased industrial activities, heavy trucking and crop fires contributed to the haze, state media CCTV reported.
