Airpocalypse now: China pollution reaching record levels

In some areas level of harmful particles in the air were 56 times the levels considered safe by the World Health Organisation Residents of north-eastern China donned gas masks and locked themselves indoors on Sunday after their homes were enveloped by some of the worst levels of smog on record. Levels of PM2.5, a tiny airborne particulate linked to cancer and heart disease, soared in Liaoning province as northern China began burning coal to heat homes at the start of the winter.