People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

Six-month old female liliger cub Eva plays in snow with her mother Zita in the Zoo in Novosibirsk, Russia, Thursday, December 5, 2013. The cub's mother is Zita, a liger – half-lioness, half-tiger, and its father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

Indian commuters travel in a local train in Kolkata, India, Tuesday, February 26, 2013. Indian Railway Minister Pawan Kumar Bansal is presenting the country's rail budget for next fiscal year in the parliament Tuesday, Feb. 26, 2013. Indian railway network is one of the world's largest, with some 14 million passengers daily and some 64,000 kilometers (40,000 miles) of railway track cut through some of the most densely populated cities. (Photo by Bikas Das/AP Photo)

An employee stands on the step of The Venice Simplon-Orient-Express at Istanbul Station in Istanbul, on August 31, 2022. The Venice Simplon Orient-Express luxury train arrives in Istanbul, completing its annual voyage along a mythical route that takes it across Europe from Paris. (Photo by Yasin Akgul/AFP Photo)

A man takes pictures of the Aurora Australis, also known as the Southern Lights, as it glows on the horizon over waters of Lake Ellesmere on the outskirts of Christchurch on April 24, 2023. (Photo by Sanka Vidanagama/AFP Photo)

Storks casts shadows as they search for food on the dried-up Lake May in southwest Turkey on October 30, 2021. (Photo by Seyit Konyal/Solent News)

Meghan Puhr participates in a virtual realty presentation during an Intel news conference before CES International, Wednesday, January 4, 2017, in Las Vegas. (Photo by John Locher/AP Photo)

Senior Buddhist monk Lobsang Tayang sits outside the Amarbayasgalant Monastery in the Baruunburen district, Selenge province, Mongolia, April 26, 2018. (Photo by Thomas Peter/Reuters)