Teachers in Xian used WeChat, mobile phone messages and live streaming apps to give classes and help students after all schools were closed due to the heavy smog shrouding major northern Chinese cities, mainland media reported. Students were ordered to study from home by the Xian Municipal Commission of Education on Monday after all kindergartens, primary schools and middle schools in Shaanxi’s provincial capital were closed because of severe air pollution, the news website People.cn reported. Hundreds of flights cancelled and delayed in Beijing, travellers stranded amid heavy smog Teachers used technology such as the free messaging app, WeChat, and live streaming apps to give lessons and also arrange students’ self-study, the report said. Teachers at Xian No 26 Middle School used real-time tutoring via live broadcasts on live-streaming platforms, the report said. The head of the city’s Cuihua Road Primary School was quoted as saying: “We launched emergency plans after receiving the order to close schools on Monday. We wanted to make sure the ‘closing schools but not suspending classes’ policy was implemented.” Beijing’s ‘smog refugees’ flee the capital for cleaner air down south This year’s first red alert for air pollution was issued in at least 23 northern cities, including Beijing, last Thursday, with the choking smog forecast to blanket much of the north of the country until Wednesday evening. Zhengzhou, the capital of Henan province, ordered all primary schools to cancel classes on Tuesday and Wednesday. Severe smog in north China grounds flights, closes highways and suspends production However, on Monday, school and factories were reported to be operating as normal in Shijiazhuang, the capital of Hebei province, close to Beijing – even though levels of PM2.5 – the finest pollutant particles smaller than 2.5 microns in diameter which can cause the greatest harm to public health – and PM10 – particles up to 10 microns in diameter – exceeded 1,000 micrograms per cubic metre – more than 100 times than the level recommended by the WHO.