<p>Thousands of runners battled thick smog at the Beijing Marathon on Sunday, with some athletes donning masks as air pollution soared to 16 times the maximum recommended level.<br /><br /></p>.<p>Organisers rejected calls to postpone the race despite the soupy white haze over the Chinese capital, but said they had laid on extra medical staff to treat injuries among the more than 25,000 registered runners.<br /><br />The level of small pollutant particles known as PM2.5, which can embed themselves deep in the lungs, reached more than 400 micrograms per cubic metre in parts of Beijing as the racers lined up.<br /><br />The World Health Organization's recommended daily maximum average exposure is 25. The US embassy in Beijing described the air on Sunday as "hazardous".<br /><br />"When I looked at the state of the mask after 10 kilometres, I decided enough was enough," said British runner Chas Pope, 39, after dropping out of the race.<br /><br />"It felt pretty ridiculous given we're meant to be running for health and fitness."<br /><br />Many top long-distance athletes stayed away from the race, which was won by Ethiopia's Girmay Birhanu Gebru in 2:10.42 seconds. His compatriot Fatuma Sado Dergo was the fastest woman with a time of 2:30.03.</p>
<p>Thousands of runners battled thick smog at the Beijing Marathon on Sunday, with some athletes donning masks as air pollution soared to 16 times the maximum recommended level.<br /><br /></p>.<p>Organisers rejected calls to postpone the race despite the soupy white haze over the Chinese capital, but said they had laid on extra medical staff to treat injuries among the more than 25,000 registered runners.<br /><br />The level of small pollutant particles known as PM2.5, which can embed themselves deep in the lungs, reached more than 400 micrograms per cubic metre in parts of Beijing as the racers lined up.<br /><br />The World Health Organization's recommended daily maximum average exposure is 25. The US embassy in Beijing described the air on Sunday as "hazardous".<br /><br />"When I looked at the state of the mask after 10 kilometres, I decided enough was enough," said British runner Chas Pope, 39, after dropping out of the race.<br /><br />"It felt pretty ridiculous given we're meant to be running for health and fitness."<br /><br />Many top long-distance athletes stayed away from the race, which was won by Ethiopia's Girmay Birhanu Gebru in 2:10.42 seconds. His compatriot Fatuma Sado Dergo was the fastest woman with a time of 2:30.03.</p>