Thick smog blanketed northern China this week, a reversal of the blue skies seen last winter as authorities dialled down environmental targets to boost flagging economic growth.
Levels of particulate matter of 2.5 microns (PM2.5), a standard for measuring air pollution, peaked above 300 on Wednesday according to data compiled by the US embassy in Beijing, a level considered “hazardous” by the US Environmental Protection Agency.
The level of pollution is 12 times the World Health Organization guidelines for outdoor air quality and the worst the city has seen in nearly 18 months.
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