Biggest sandstorm in decade turns Beijing skies yellow

City residents used goggles, masks and hairnets to protect themselves from the choking air, with landmarks including the Forbidden City and the distinctive headquarters of state broadcaster CCTV partly obscured behind an apocalyptic-looking haze of dust and sand.The city government ordered all schools to cancel outside sport and events and advised those with respiratory diseases to stay inside, while some highways were partially closed.The poor air quality was due to a sandstorm from northern Mongolia, where authorities said it had left several dead and dozens missing, before being carried south by winds and reducing visibility in Beijing to less than 500 metres.Authorities described it as the worst sandstorm in a decade to hit the city, compounding days of hazardous PM 2.5 pollution in the capital. Under heavy skies, which draped buildings in an eerie glow, Beijing residents fretted over the health risks. "I feel every breath will give me lung problems," Beijing resident Zhang Yunya told AFP.Flight tracker Variflight said more than 350 flights had been cancelled at the two airports on Monday, with dozens more delayed."This sandstorm is very fierce," said Pan Xiaochuan, a Beijing-based environmental health expert."I remember the sandstorms ten years ago blew away in less than an hour, but I'm afraid that this one will not have passed through the whole day."Six people were killed by the sandstorms in neighbouring Mongolia, the country's national emergency management agency said Monday, including a five-year-old boy from a herder family.Another 81 people were still missing as strong winds and duststorms swept the landlocked country, which borders China.Discussion of the orange haze lit up online discussions -- with 210 million views on social media platform Weibo by Monday afternoon. "This orange red sandstorm makes it looks like the end of the world," said one Weibo user.Pollution in the city was at "hazardous" levels, according to air quality monitoring website Aqicn, as the reading soared off the scale for many apps.Aqicn said levels of PM 10 large particulate matter were nearly 20 times the World Health Organizationtarget="_blank"'>This was exacerbating the sandstorm conditions, which are "a result of extreme weather conditions and desertification", he said.