Air pollution reached “hazardous” levels in Beijing on Saturday. Some scientists have labeled the city as “unlivable” because of the poor air quality.

Pollution masks have become a part of everyday life in the capital. I started wearing them a couple of years ago, after I bought a bike and began using it to commute around the city.

View of suburban Beijing from a subway car. An Australian soccer player who spent a year in China told the magazine FourFourTwo that playing in the smog “was like closing your garage door, turning your car exhaust on and running around in the enclosed space.”