Shanghai continued to suffer smoggy weather this morning with the air quality index stayed at 246 by 9am today. The city’s air has been in the several polluted zone since yesterday, the worst day for air pollution since the index was launched last December. PM2.5 density stayed above 160 micrograms per cubic meter by 8am, double the national limit of 75. PM2.5 refers to airborne particles which are smaller than 2.5 micrometers in diameter. They are the main cause of urban smog and are harmful to human health. Pedestrians put on masks to avoid the particles that can cause lung or cardiopulmonary health problems. The Shanghai Education Commission issued a directive to schools before classes began that they should reduce outdoor activities. A second notice in the morning ordered a halt to outdoor activities. Students who were late or absent yesterday and today would […]