In this photograph taken on March 1, 2017, a man covers his face as he walks along a dusty road in Kathmandu. - Nepal's government is trying to tackle rising pollution levels in the smog-choked Kathmandu Valley, but standing in the way is a powerful bus mafia that controls the capital's roads. The rulers of Kathmandu's roads are a web of transport syndicates made up of private bus owners that have repeatedly blocked official attempts to modernise the highly inefficient bus network. (Photo by PRAKASH MATHEMA / AFP) / TO GO WITH AFP STORY Nepal-pollution-transport,FOCUS by Ashok Dahal and Annabel Symington