Ladies enjoyed themselves last night – while keeping safe with their face masks on in Liverpool, United Kingdom on Saturday, December 5, 2020, after coronavirus restrictions were eased following the end of the second national lockdown. (Photo by London News Pictures)

A protester in an Elmo mask dances during the Justice for George Floyd Philadelphia Protest on Saturday, May 30, 2020. Demonstrators took to the streets across the United States to protest the death of Floyd, a black man who was killed in police custody in Minneapolis on May 25. (Photo by Matt Rourke/AP Photo)

A climate activist wears an oxygen mask to demonstrate the possibility of pumping oxygen from a tree in a bottle in the future, during a protest against the government's deforestation practices of Sri Lanka's main wildlife forests for developments in Colombo, Sri Lanka on March 22, 2021. (Photo by Dinuka Liyanawatte/Reuters)

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)

Anti-pollution protesters wearing traditional costumes and contemporary gas masks ride bicycles in the Qingming Grand river park in Kaifeng, Henan Province, China on January 1, 2017. The Beijing Municipal Environmental Protection Bureau extended an “orange alert” for heavy air pollution for three more days. (Photo by SIPA Asia/Rex Features/Shutterstock)

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)