This week a super-smog has covered Harbin in the north-east of China. It seems that a combination of the switching on of the coal-powered municipal heating system (temperatures plummet to -40C in winter) together with, ironically, an unseasonably warm week, plus the usual car exhaust and other pollution issues, has resulted in the PM2.5 level rising to an incredible 1,000 micrograms per cubic metre, forty times the recommended daily max. Today visibility dropped to 50m in much of the city and the international airport, highways and 2,000 schools have been closed.
Last week the WHO's cancer research agency officially classified outdoor pollution as carcinogenic. Hey ho.