Shanghai warned children and the elderly to stay indoors as PM2.5 levels reached almost six times that recommended by the World Health Organization for safe breathing.
The air quality index was 201 as of 7 a.m., indicating “heavy pollution,” second worst in a six-tier system, according to the website of the city’s environmental monitoring center.
The level of particles that are smaller than 2.5 microns in diameter was 141.6 micrograms per cubic meter. The pollutants are more hazardous than other particulate matter, according to WHO.
Shanghai saw record levels of smog earlier this month, forcing flight cancellations and prompting the government to issue warnings to keep children indoors and order vehicles off the road. The pollution index surged to a record 482 on Dec. 6, reaching the highest “severe” level, according to the China Daily.