Indian boy Hassan Malik works in a leather shoe factory at Topsia in Calcutta, eastern India, 19 November 2013. The leather industry occupies an important place in the Indian economy. It is an employment intensive sector with a vast potential for growth and exports but also a pollution intensive industry that relies on cheap labor. One of the major production centers for leather and leather products is located in Calcutta, West Bengal. Hundreds of tanneries are operated in the city’s Tiljala, Topsia and Tangra districts. They are mostly run by local families living and working under poor conditions. (Photo by Piyal Adhikary/EPA)

Two men standing on a high catwalk, surveying the construction of the Brooklyn Bridge, with Manhattan in the background, New York City, 1877. (Photo by Museum of the City of New York/Archive Photos/Getty Images)

A women rides a motor bike on a street covered with volcanic ash from an eruption of Mount Kelud, in Solo, Indonesia, Friday, February 14, 2014. A major volcanic eruption in Indonesia blasted clouds of ash and debris 18 kilometers (12 miles) into the air on Friday, forcing authorities to close six airports, cancel flights elsewhere in Southeast Asia and evacuate more than 100,000 people from the mountain. (Photo by Hafidz Novalsyah/AP Photo)

A visitor passes behind the sculpture “Puma-Dentist” made with plastic, wax and original heads of a puma and a hind by Austrian artist Deborah Sengl during an exhibition at the art gallery Deschler in Berlin April 15, 2008. (Photo by Fabrizio Bensch/Reuters)

Passengers check their mobile devices as a bin is full of garbage during a protest by the cleaning staff at Barcelona's airport, Spain, December 1, 2016. (Photo by Albert Gea/Reuters)

A farmer rides a truck in a village near Nong Khai, Thailand, September 16, 2015. (Photo by Jorge Silva/Reuters)

A muslim pilgrim walks through the site where dead bodies are gathered in Mina, Saudi Arabia during the annual hajj pilgrimage on Thursday, September 24, 2015. Hundreds were killed and injured, Saudi authorities said. The crush happened in Mina, a large valley about five kilometers (three miles) from the holy city of Mecca that has been the site of hajj stampedes in years past. (Photo by AP Photo)

The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)