Faced with pollution conditions that experts say is like a "nuclear winter", people in Beijing are trying everything to protect themselves from the choking smog and fumes. The country's toxic air pollution has left Beijing with near zero visibility for the last six days, blocking out the sun to such an extent that it is impeding photosynthesis in plants, and threatening the nation's food supply.

The AFP reports that "Beijing's official reading for PM 2.5 -- small airborne particles which easily penetrate the lungs and have been linked to hundreds of thousands of premature deaths -- stood at 501 micrograms per cubic metre on Wednesday afternoon." The World Health Organization's safety limit is at 25 micrograms. 

Face masks (kind of like what construction workers use or the kind that you see in hospitals) that filter out some those particles have been one way people have been protecting themselves. Some, as our friends over at Quartz point out, work better than others. But almost all are in a scarcity.

"Of the 29 models of face-masks on Tmall.com, a business-to-consumer shopping platform, 26 were sold out or unavailable on Wednesday," the AFP reported, explaining that other brands like Totobobo and Vogmask were facing shortages too. Totobobo won't be replenishing their supplies until April and Vogmask only had children's masks available. 

In a curious move, China's president Xi Jinping made a public appearance on Tuesday in Beijing. He was outside and not wearing a face mask, hoping to send a message that he's one of the people and that the air safe. Or that he's has no regard for lung cancer. "The leader isn’t wearing a mask. He’s using willpower to repel the smog," a blogger wrote.