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)

A face of a devotee covered with her cloth is pictured as she offers prayers to the rising sun during the "Chhat" festival in Kathmandu, Nepal November 18, 2015. Hindus in Nepal celebrate "Chhat", a four-day festival that honours the sun god by praying at sunrise and sunset and seeking blessings for ones family by giving offerings. (Photo by Navesh Chitrakar/Reuters)

A Maasai moran athlete has his face smeared with red ocher paint during preparations for the 2016 Maasai Olympics at the Sidai Oleng Wildlife Sanctuary, at the base of Mt. Kilimanjaro, near the Kenya-Tanzania border in Kimana, Kajiado, Kenya December 10, 2016. (Photo by Thomas Mukoya/Reuters)

A woman wearing a protective face mask makes merit during the Songkran holiday which marks the Thai New Year during the coronavirus disease (COVID-19) outbreak, in Bangkok, Thailand, April 13, 2022. (Photo by Chalinee Thirasupa/Reuters)

A man helps a woman with blood on her face after security guards saw her looting in a hotel during a protest demanding the resignation of Haiti's Prime Minister Ariel Henry after weeks of shortages, in Port-au-Prince, Haiti on October 10, 2022. (Photo by Ralph Tedy Erol/Reuters)

A citizen wearing protective suit shops at a market in Santiago, Chile, April 16, 2020 Chile has taken stringent measures to contain the virus, including imposing a night time curfew, suspending classes, closing non-essential businesses, and mandating the use of face masks on all public transit. (Photo by Jorge Villegas/Xinhua News Agency)

Cheerleaders wearing face masks due to the outbreak of the coronavirus disease (COVID-19) are seen at the first professional baseball league game of the season at Taoyuan International baseball stadium in Taoyuan city, Taiwan, April 11, 2020. (Photo by Ann Wang/Reuters)

A woman wearing a face mask and a child sit between rail tracks, during the imposition of large-scale social restrictions by the government to prevent the spread of the coronavirus disease (COVID-19) in Jakarta, Indonesia, April 12, 2020. (Photo by Willy Kurniawan/Reuters)