Pedestrians in downtown Beijing wore masks or covered their mouths and noses with napkins, scarves and hands.
A number of monitoring sites showed PM10 readings reaching 1000 micrograms per cubic meter on Wednesday evening, according to the Beijing Municipal Environmental Monitoring Center.
(This level of Particulate Matter is considered hazardous to health and the advice is that everyone should avoid any outdoor exertion and people with respiratory disease, such as asthma, should remain indoors.)
They spread across China to South Korea and Japan, and even to the US.
Asian Dust has become a serious problem due to the increase of industrial pollutants contained in the dust. Intensified desertification in China, as well as the drying up of the Aral Sea of Kazakhstan, has made these storms longer lasting and more intense.