SHANGHAI’S air reached severely polluted last night, its worst this year, as the city air quality index passed 300.
This followed three days of smog, though forecasters said the arrival of a cold front today with northeasterly winds should disperse pollutants.
Although yesterday was only January 11, it was the eighth polluted day of 2015, and saw the index peaking at 302 — in the highest pollution bracket — at 8pm.
The Shanghai Environmental Monitoring Center issued an air pollution alert. Children, the elderly and people with heart and lung disease were told to stay inside, and those working outside advised to take measures to protect themselves from hazardous particles.
The index fluctuated through the day, staying above 200 at heavily polluted throughout the morning, before dropping below 200 at 1pm.
However, after falling to 168 at 4pm, it climbed again, passing 300, the designation of severe pollution at 8pm.
Levels of the main pollutant PM2.5 — tiny particles especially harmful as they can get deep into the respiratory system — also occurred in two waves.
They reached 240 micrograms per cubic meter at 2am, dipped to 220 at 6am and rose to 240 again at 10am.
Then they fell to 120 micrograms at 4pm but returned to some 250 micrograms at 8pm — 10 times the World Health Organization safe limit.
Local environmental authorities said this series of polluted days was caused by the pollutants from northwestern China and still conditions in Shanghai.
But there should be respite today.
Under high pressure, temperatures will range from 5 to 9 degrees Celsius with a sun and cloud, said the Shanghai Meteorological Bureau.
Tomorrow and Wednesday wet weather is forecast, before dry though still cloudy conditions on Thursday. But on Friday, drizzle is forecast.
From Tuesday and Friday, temperatures will range from 6 to 12 degrees.
The only days this year when clean air was recorded were January 1, 7 and 8.