Beijing is continuing its struggles with high concentrations of PM2.5, a type of particulate matter in air, according to Grist. In the early days of January 2015, the Chinese city endured PM2.5 levels over 500 on the Air Quality Index. The figure is particularly disturbing because the AQI scale only goes to 500.
Those readings were captured by the U.S. embassy in Beijing, which manages its own set of air quality monitoring devices. Another monitoring station managed by the Beijing municipal government reported an AQI of 430 for the same period, which is still quite hazardous despite being lower than the U.S.-reported total.
According to Grist, the low air quality readings still pale in comparison to those registered in early 2013. At that point, AQI reached an estimated 755 and the air mass responsible covered more than one million square miles of China. American expatriates living in the country even gave it a nickname at the time: the “airpocalypse.”
Top image: Reading of Beijing Air Quality Index. (Credit: U.S. embassy in Beijing)