Air quality reached extremely hazardous levels, about 50 times World Health Organization maximums, in the northeastern Chinese industrial city of Shenyang, as locals began burning coal to heat homes for winter.
Over the weekend, Shenyang endured PM2.5 readings that exceeded 1,000, even 1,400 micrograms, per cubic meter, at some measuring stations, state news agency Xinhua reported.
The Chinese government considers 35 micrograms per cubic meter is a healthy maximum, while the WHO’s recommended maximum is a 24-hour average of 25 micrograms.
Pictures shared in social media showed smog so thick that buildings in Changchun, the capital of Jilin province in the northeast, were rendered invisible.
China’s chronic air pollution generally gets worse in winter, when power consumption —much of it fuelled by coal — rises along with demand for heating.
Emissions from industrial plants and the increasing use of cars also are major causes of air pollution in the Asian giant.