Beijing ordered hundreds of factories to shut and allowed children to skip school as choking smog reached over 25 times safe levels on Tuesday, casting a cloud over China's participation in Paris climate talks, AFP reports.
A thick grey haze shrouded the capital with concentrations of PM 2.5, harmful microscopic particles that penetrate deep into the lungs, as high as 634 micrograms per cubic meter.
The reading given by the US embassy dwarfs the maximum recommended by the World Health Organisation, which is just 25 micrograms per cubic meter