A migrant labourer brushes his teeth in front of a scrapped helicopter model in Mumbai, India, April 13, 2016. (Photo by Danish Siddiqui/Reuters)

Tattoo artists work on clients during the second International Tattoo Festival in Sochi, Russia, April 23, 2016. (Photo by Kazbek Basayev/Reuters)

The Mount Bromo volcano erupts in the Bryce Canyon, Utah. (Photo by Reynold Dewantara/2016 National Geographic Travel Photographer of the Year Contest)

A masked reveller hangs from an inflatable balloon during the first day of the carnival in Venice, Italy, January 23, 2016. (Photo by Manuel Silvestri/Reuters)

A worker works at a plant of Hyundai Motor in Asan, South Korea, January 27, 2016. (Photo by Kim Hong-Ji/Reuters)

Men pull as a boy stands on a soap cutter in a soap factory in Idlib province, Syria January 30, 2016. (Photo by Ammar Abdullah/Reuters)

Revellers parade for Gavioes da Fiel samba school during carnival in Sao Paulo, Brazil, February 6, 2016. (Photo by Paulo Whitaker/Reuters)

Record snowfall in the Sahara Desert near the town of Ain Sefra in Algeria on January 21, 2017. (Photo by Geoff Robinson/Rex Features/Shutterstock)