NBC: Beijing and other parts of northern China were stung by hazardous air pollution levels Thursday as strong winds blew a sandstorm through the region.
Air in the capital turned a yellowish hue as sand from China's arid northwest blew in, turning the sky into a noxious soup of smog and dust.
At 6 a.m. local time, the U.S. Embassy's air quality index showed a reading of 516 for particles less than 2.5 micrometers in diameter. Known as PM2.5, such particles are considered particularly dangerous...