Beijing's worst air in over a year

Beijing's air quality deteriorated to the worst in a year-and-a-half on Wednesday, with the authorities forecasting it would be at least another day before conditions improve. Levels of the most-hazardous, tiny particulate matter - known as PM 2.5, which can lodge deep in a person's lungs - soared to 288 as of noon in the Chinese capital, according to data published by the US Embassy in Beijing.

That's 11 times higher than what the World Health Organization says is the average level of healthy exposure in a 24-hour period. It's also higher than PM 2.5 levels recorded in several Californian cities where the air has been affected by local wildfires, reports Bloomberg. The reading was 161 in Napa Valley, 188 in Sacramento and 164 in San Francisco as of 11am Beijing time, the US government's AirNow website showed. Beijing's pollution levels, though high on Wednesday are also significantly below heights reached earlier in the decade.

The gauge reached 761 on March 22, 2010, before a government campaign to curb pollution by cutting down on the use of coal and fuel oil. Officials are particularly focused on improving air quality in the winter heating season, which runs from November through March, when energy demand is at its peak. Many residents of the Chinese capital responded by posting pictures to social media with the tag "gone are the buildings", a practice that has spread as the air worsens during the winter.

Some areas of Hebei Province and Beijing experienced visibility of less than 50m. "The only motivation to go to work this morning is that my office has a much better ventilation system and hundreds of air purifiers to ensure the air quality is better than at home," quipped one person on social media.