Unprecedented levels of air pollution effectively closed the city of Harbin in northern China earlier this week. Smog limited visibility in some places up to 30 feet, and measurements of fine particulate pollution skyrocketed a record 40 times higher than the worse safe level set by the World Health Organization, according to the Washington Post.
In the city of 11 million, schools, public bus routes, and the airport were all forced to suspend activities given the unsafe conditions. Hospital admittances of patients with respiratory problems soared an additional 30 percent.
The cause, according to local Chinese news outlets, was the first day of the city’s heating being turned on before winter. China’s air quality has consistently been found to be harmful in the recent decades of the country’s rapid industrial development.