Two carnival revellers masquerade as Leonardo da Vinci's painting “Mona Lisa” pose in St. Mark's Square in Venice, Italy, Sunday, January 31, 2016. Carnival-goers in Venice are being asked by police to momentarily lift their masks as part of new anti-terrorism measures for the annual festivities. (Photo by Domenico Stinellis/AP Photo)

A Chinese woman wears a mask to protect from particles blown in during a sandstorm as she walks in the street on May 4, 2017 in Beijing, China. Sandstorms are common in northern China during the spring season and are caused when heavy winds from Mongolia in the north brings sand and pollutants that can blanket Chinese cities and cause air quality to deteriorate. (Photo by Kevin Frayer/Getty Images)

Pedestrians wear masks as smoke and haze from bushfires in New South Wales blankets the CBD in Sydney, Australia, 10 December 2019. The New South Wales environment department says visibility across east and southwest Sydney was at a “hazardous” level on Tuesday morning, while air quality was poor in southwest Sydney and hazardous in northwest Sydney. (Photo by Steven Saphore/EPA/EFE)

Revellers in Leeds, United Kingdom were excited to be out and about again on July 18, 2021. At a minute past midnight, England dropped most of its remaining Covid-19 social restrictions, such as those requiring indoor mask-wearing and limits on group gatherings. These changes come despite rising infections, pitting the country's vaccination programme against the virus's more contagious Delta variant. (Photo by Ioannis Alexopoulos/PA Wire Press Association via Getty Images)

A giant classic Hindu Ramayana statue dons a face mask to remind passengers to keep to coronavirus precautions at the Suvarnabhumi airport in Bangkok, Thailand, Wednesday, July 21, 2021. The Civil Aviation Authority of Thailand has ordered a halt to all domestic flights operating from the most severely affected provinces effective Wednesday. Exceptions are allowed for flights to destinations that are part of a plan that allows vaccinated travelers from abroad to stay for two weeks on popular islands such as Phuket and Samui without quarantine confinement. (Photo by Sakchai Lalit/AP Photo)

Students wearing masks as a precaution amid the spread of COVID-19 put away a Cuban flag so it does not get wet in the rain on their first day of school after months without face-to-face classes in Havana, Cuba, Monday, November 8, 2021. As Cuba approaches the announced date of Nov. 15 for the reopening of the entire country to the world, getting children back to school is one of its priorities. (Photo by Ramon Espinosa/AP Photo)

A pedestrian wearing a face mask to protect against coronavirus, walks in front of a mural, at a metro station in Athens, Greece, Monday, November 15, 2021. Authorities say the rate of death related to COVID-19 in Greece has reached its highest level in six months as roughly one-third of the country's population remains unvaccinated. (Photo by Thanassis Stavrakis/AP Photo)

Mexico City resident Romina Montoya takes a playful selfie wearing a protective face mask over her eyes and nose, in Playa del Carmen, Quintana Roo state, Mexico, Wednesday, January 6, 2021. Concern is spreading that the critical winter holiday tourism success could be fleeting because it came as COVID-19 infections in both Mexico and the United States were reaching new heights. (Photo by Emilio Espejel/AP Photo)