Tianjin was shrouded in thick brown dust this morning as a result of heavy winds blowing in from Inner Mongolia and other parts of northwestern China.
The China Meteorological Administration announced a yellow alert on Monday morning, saying that the sandstorms had spread from Inner Mongolia into Bejing, Gansu, Shanxi and Hebei.
Tianjin official air quality index reached a maximum level of 500 on Monday morning, with floating particles known as PM10 reaching 2,000 micrograms per cubic metre in some districts.
Readings of PM2.5, smaller particles that infiltrate the lungs, were also approaching 300 micrograms per cubic metre, far higher than China's standard of 35 micrograms.