SHANGHAI, Dec 26 — Shanghai warned children and the elderly to avoid prolonged or heavy outdoor activities as haze engulfed the city, sending PM2.5 surging overnight to more than 12 times World Health Organisation guidelines.
The city issued a “yellow” alert for haze, the third lowest in a four-tier warning system, urging drivers to be cautious and people with respiratory illnesses to wear masks when going outside, the Shanghai government’s microblog said.
The level of PM2.5 pollutants began a continuous climb from about midnight, hitting 309 micrograms per cubic metre as 7am.
The WHO recommends exposure of no more than 25 over a 24- hour period for particles smaller than 2.5 microns in diameter that are more dangerous than other particulate matter.
The air quality index was 160, signaling “moderate pollution,” the third worst of six levels, the city’s environmental monitoring center said.
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. — Bloomberg
