Thousands of runners signed up for the Beijing marathon, hoping to better themselves in the 42 km race. But the 34th Beijing International Marathon which took place on Sunday was not a fit place for a record, as air 
pollution soared to 16 times the maximum recommended level.

The air in Beijing is among the most polluted urban areas in the world. The level of small pollutant particles known as PM2.5 reaches a critical level – more than 400 micrograms per cubic meter. These particles are especially dangerous with a 36% increase in lung cancer per 10 μg/m3.

“I was basically a vacuum cleaner,” William Liu, a 30-year-old banker, told Bloomberg after completing the marathon.

Even the People’s Daily, the Communist Party’s newspaper warned that Beijing’s air was “not suitable for outdoor activities”. Some runners were forced to abandon the race; one unnamed Chinese participant told the Telegraph that he was pulling out of the race because of the smog. Ying Wei, a 23-year-old runner, admitted his “lung hurt quite badly during and after the race”.

But most competitors decided to ignore the health warnings and run to the best of their capacity. Organizers told the Beijing News they handed out 140,000 water-soaked sponges to athletes, advising them to “clean” their skin after it was “exposed to the air”.

Luo Changping, a Chinese journalist, posted a photograph of one runner sporting a military-style gas mask.

“I’m not running the marathon. I’m going back to the World War,” the journalist wrote.

Only 1% of the country’s 560 million city dwellers breathe air considered safe by the European Union, because all of its major cities are constantly covered in a “toxic gray shroud”. Before and during the 2008 Summer Olympics, Beijing was “frantically searching for a magic formula, a meteorological deus ex machina, to clear its skies for the 2008 Olympics.”

Beijing on a clear day (left) and on a smoggy day (right). Image via Wiki Commons

According to the National Environmental Analysis released by Tsinghua University and The Asian Development Bank in January 2013, 7 of 10 most air-polluted cities are in China, including Beijing.