Environment

Pollution

China's 10th-largest city shuts down because of extreme air pollution - Harbin, China, the nation's 10th most populous city with a population of 11 million, has virtually shut down today because of extreme levels of air pollution reaching up to 1,000 micrograms per cubic meter. The safe level recommended by the World Heath Organisation is just 25 micrograms per cubic meter. The dense pollution was created by stagnant air on a day when the city's heating systems kicked in for the first time this fall. With visibility less than 50 yards, the airport was forced to close, as well as most schools and some roads.