Dancers in costume at Thangbi Mani Tsechu (festival), Jakar, Bumthang, Chokor Valley, Bhutan, Asia

Workers in the offshore industry practise escaping from a smoke chamber as part of an industry training course, Billingham, Teesside, England, United Kingdom, Europe

Beekeeper Bill Mackereth checks his hives for signs of Varoa mite damage, Cockermouth, Cumbria, England, United Kingdom, Europe

A smoke mask in case of fire in a hotel bedroom in China, Asia

Person wearing mask in smoke

Anti nuclear power demonstration at the Gundremmingen nuclear power plant, the most powerful German nuclear power plant, Gundremmingen in Guenzburg, Bavaria, Germany, Europe

Wooden mask carver in a window, framed by painted wooden masks, wooden mask carving workshop, Bad Aussee, Styria, Austria, Europe

Hacker with an anonymous mask with a computer and making a fight symbol, with a background of smoke and colored leds

Hacker with anonymous mask with a symbol of fight, with a background of smoke and colored led

Smog in the streets of Pangkalanbun, Central-Kalimantan, Borneo, Indonesia

Welder at the Medeber Market, where artisans recycle old tyres and tins to make new artifacts, Asmara, Central Region, Eritrea

Welder at the Medeber Market, where artisans recycle old tyres and tins to make new artifacts, Asmara, Central Region, Eritrea

Beekeeper inspecting hives during honey production