International

An experimental tower over 100 metres (328 feet) high in northern China – dubbed the world’s biggest air purifier by its operators – has brought a noticeable improvement in air quality, according to the scientist leading the project, as authorities seek ways to tackle the nation’s chronic smog problem.

The tower has been built in Xian in Shaanxi province and is undergoing testing by researchers at the Institute of Earth Environment at the Chinese Academy of Sciences.

The head of the research, Cao Junji, said improvements in air quality had been observed over an area of 10 square kilometres (3.86 square miles) in the city over the past few months and the tower has managed to produce more than 10 million cubic metres (353 million cubic feet) of clean air a day since its launch. Cao added that on severely polluted days the tower was able to reduce smog close to moderate levels.