Guardian: It was almost 20 years ago that Ma Jun sat and watched the rainbow-coloured River Fen, in Shanxi province. As he turned to the skies in this coal and industrial heartland of north China he could see dozens of chimneys bellowing out their fumes.
He had been sent to the province on an assignment while working as a researcher for a foreign journalist in the late 1990s. The story then was about family planning and its impact on local communities, but it was the devastating pollution he witnessed that...