China’s Xian chokes on smog specks ‘harder than steel’
Researchers in pollution-prone Xian test the properties of the city’s bad air but health specialists say the bigger concern is just how small the particles are
Residents in one of China’s most polluted cities are breathing in smog particles that are harder than steel, according to Chinese researchers.
But medical experts said the size of the particles – and not their hardness – was the main concern for human health.
A team of scientists from Xian Jiaotong University’s school of material science and engineering collected samples of smog particles around Xian, in northwestern China’s Shaanxi province, in the winter of 2013, when the city was blanketed in pollution.
Xian, home to 8.7 million people, has some of the worst air pollution in the country, last year ranking 374 among 387 cities monitored for air quality, official figures showed.
“We wanted to figure out what formed smog particles,” Liu Boyu, a researcher from the university, said.
“Since we are researchers on the strength of materials, we wanted to see how hard smog particles were.”