China ENGULFED by smog at 4000% times safe limit!

A choking cloud of air pollution 4,000 per cent as dangerous as the World Health Organization's recommendation of daily airborne particulate exposure has virtually shut down one of northeastern China's most populous cities.


On Monday, Harbin – the capital and largest city in Heilongjiang province – was engulfed by an "airpocalypse" of fine particulate matter known as PM_2.5, with readings as high as 1,000 micrograms per cubic meter in some parts of the metro area of 11 million souls, Reuters reports. The WHO's recommendation [PDF] for 24-hour PM_2.5 exposure is 25 µg/m³.
PM_2.5 is particularly nasty stuff. As the US Environmental Protection Agency explains:

Particles less than 10 micrometers in diameter (PM₁₀) pose a health concern because they can be inhaled into and accumulate in the respiratory system. Particles less than 2.5 micrometers in diameter (PM_2.5) are referred to as "fine" particles and are believed to pose the greatest health risks. Because of their small size (approximately 1/30th the average width of a human hair), fine particles can lodge deeply into the lungs.

Being in northeastern China, Harbin can be bitingly cold – one of its nicknames, in fact, is "Ice City" – and according to Reuters, China's official Xinhua news agency indirectly blamed the airpocalypse on the cold, saying that the massive pollution was caused by residents and the local government firing up their heating systems for the first time this winter.
Whatever the proximate cause, the surge of PM_2.5 has brought the city to a near standstill – schools have suspended classes, the airport has shut down, and traffic has snarled as the cloud of pollution reduced visibility to as low as 10 meters, as the video below shows.