Fog engulfs northern China

Dense fog that has snarled traffic and forced flight cancellations in Beijing and elsewhere in China was not expected to clear until Tuesday, authorities said.Beijing and other regions in northern China, including Tianjin and Hebei Provinces, have been enveloped by the fog since Saturday, China Daily reported.Meteorologists said the fog could spread to other provinces.The moist air due to melting snow and absence of winds had helped the fog to remain stationary in Beijing and other places, they said.Major highways in the region were closed Sunday due to the fog and traffic was not allowed in some of the areas near Beijing, the report said. Hundreds of flights were canceled.There was concern that particulates in the fog could cause respiratory diseases, the BBC reported.