A new episode of smog began to affect the Beijing, Tianjin, and Hebei regions, as well as the provinces of Shandong, Shanxi, and Henan, on Friday, January 12. This air pollution is expected to persist until January 17. Authorities in the capital city and Tianjin have issued orange alerts set to remain in effect until January 15. Children and the elderly have been advised to stay indoors, some construction activities have been ordered suspended, and heavy-duty vehicles have been pulled off the roads. According to the health authorities, the density of PM2.5 particles may exceed 250 micrograms per cubic meter of air. The smog is expected to be dispersed by a cold front forecast to arrive January 18.
Under China's four-tier warning system, red alerts are the most severe, followed by orange, yellow, and blue Orange alerts are issued when the average air quality index is forecast to exceed 200 for three consecutive days. More than nine people out of ten in China are exposed to ¬concentrations of PM2.5 - the tiny particles most hazardous to health - above what the World Health Organization considers healthy levels.
Individuals present in northern China - particularly those with existing respiratory issues - are advised to minimize nonessential outdoor activity until January 17, to monitor the situation, and to seek medical attention if needed.