A protective face mask is seen on the pavement in Paris during a lockdown imposed to slow the rate of the coronavirus disease (COVID-19) in France, April 24, 2020. REUTERS/Charles Platiau 

A discarded mask is seen on the ground, as the global outbreak of coronavirus disease (COVID-19) continues, in Los Angeles, California, U.S., April 23, 2020. REUTERS/Lucy Nicholson 

A discarded face mask is seen on the floor, as the spread of the coronavirus disease (COVID-19) continues, in Northwich, Britain April 23, 2020. REUTERS/Molly Darlington 

A face mask used to protect from the coronavirus disease (COVID-19) is seen on the grass near a logistics center in Lauwin-Planque, northern France, April 22, 2020. REUTERS/Pascal Rossignol 

A protective face mask lies on the street at Trastevere district as the spread of coronavirus disease (COVID-19) continues in Rome, Italy, April 19, 2020. REUTERS/Alberto Lingria 

A protective face mask lies on the street at Trastevere district as the spread of coronavirus disease (COVID-19) continues in Rome, Italy, April 19, 2020. REUTERS/Alberto Lingria 

A protective face mask lies on the street during the lockdown following the coronavirus disease (COVID-19) outbreak in Ronda, southern Spain, April 19, 2020. REUTERS/Jon Nazca 

A man's hand is seen after washing off the home quarantine stamp during a nationwide lockdown to slow the spreading of the coronavirus disease (COVID-19) on a street in Dharavi, one of Asia's largest slums, Mumbai, India, April 11, 2020. Picture taken April 11, 2020. REUTERS/Francis Mascarenhas 

Oxygen cylinders are pictured at an out-of-order oxygen plant of a hospital allocated for the coronavirus patients in preparation for any possible spread of the coronavirus disease (COVID-19), in Sanaa, Yemen April 8, 2020. Picture taken April 8, 2020. REUTERS/Khaled Abdullah 

A medical glove lies discarded in a park as the spread of the coronavirus disease (COVID-19) continues in Manchester, Britain, April 13, 2020. REUTERS/Phil Noble 

Discarded disposable gloves are seen on a pavement in London as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 11, 2020. REUTERS/Toby Melville 

A protective face mask is seen on the floor near Westminster Bridge as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 10, 2020. REUTERS/Toby Melville 

A surgical mask is seen discarded on a city sidewalk during the outbreak of the coronavirus disease (COVID-19) in the Brooklyn borough of New York City, New York, U.S., April 7, 2020. REUTERS/Stefan Jeremiah 

A protective face mask is seen in the rain at a deserted street, during the coronavirus disease (COVID-19) outbreak in Madrid, Spain, March 31, 2020. REUTERS/Susana Vera TPX IMAGES OF THE DAY 

A glove is seen, during the coronavirus disease (COVID-19) outbreak in Bari, Italy, March 31, 2020. REUTERS/Alessandro Garofalo 

Used protective masks are seen in a bin at a laboratory where a fast test for coronavirus is performed, as the spread of the coronavirus disease (COVID-19) continues, in Frankfurt, Germany, March 31, 2020. REUTERS/Kai Pfaffenbach 

A Hindu holy man, or sadhu, holds prayer beads as he offers prayer at the premises of Pashupatinath Temple a day ahead of the Shivaratri festival in Kathmandu, Nepal February 20, 2020. REUTERS/Navesh Chitrakar 

A Hindu holy man, or sadhu, prepares marijuana at the premises of Pashupatinath Temple a day ahead of the Shivaratri festival in Kathmandu, Nepal February 20, 2020. REUTERS/Navesh Chitrakar 

A Hindu holy man, or sadhu, prepares marijuana at the premises of Pashupatinath Temple ahead of the Shivaratri festival in Kathmandu, Nepal February 19, 2020. REUTERS/Navesh Chitrakar 

Elderly women climb the stairs at a park in Minsk, Belarus February 11, 2020. Picture taken February 11, 2020. REUTERS/Vasily Fedosenko 

A discarded face mask lies on the ground outside Sunnybrook Hospital, where a patient is being treated in isolation for what Canadian health officials call the first presumptive confirmed case of novel coronavirus, in Toronto, Ontario, Canada January 26, 2020. REUTERS/Carlos Osorio 

A placard of Uncle Sam sits outside a house at Indianola, Iowa, U.S., January 23, 2020. REUTERS/Ivan Alvarado 

A monkey runs along the roof of the decommissioned Voi train station in Voi, Kenya, November 13, 2019. REUTERS/Baz Ratner SEARCH "MOMBASA-NAIROBI TRAIN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

A blackboard, with an old train schedule written on it, hangs at the decommissioned Voi train station in Voi, Kenya, November 13, 2019. REUTERS/Baz Ratner SEARCH "MOMBASA-NAIROBI TRAIN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

The wreck of the Golden Harvest, a fishing vessel that ran aground on the banks of Loch Linnhe in 2011, is seen in front of the UK's highest mountain Ben Nevis near Fort William, Scotland, Britain November 10, 2019. REUTERS/Russell Cheyne 

The wreck of the Golden Harvest, a fishing vessel that ran aground on the banks of Loch Linnhe in 2011, is seen in front of the UK's highest mountain Ben Nevis near Fort William, Scotland, Britain November 10, 2019. REUTERS/Russell Cheyne 

The wreck of the Golden Harvest, a fishing vessel that ran aground on the banks of Loch Linnhe in 2011, is seen in front of the UK's highest mountain Ben Nevis near Fort William, Scotland, Britain November 10, 2019. REUTERS/Russell Cheyne 

The wreck of the Golden Harvest, a fishing vessel that ran aground on the banks of Loch Linnhe in 2011, is seen in front of the UK's highest mountain Ben Nevis near Fort William, Scotland, Britain November 10, 2019. REUTERS/Russell Cheyne 

Windows of an old house are seen in the Darb al-Labbana hillside neighbourhood in Cairo, Egypt September 3, 2019. Picture taken September 3, 2019. REUTERS/Mohamed Abd El Ghany 

Metering devices are seen in the central control room of the decommissioned Ignalina nuclear power station in Visaginas, Lithuania July 24, 2019. Picture taken July 24, 2019. REUTERS/Ints Kalnins 

General view of the old city from the river side in Mosul, Iraq June 30, 2019. Picture taken June 30, 2019. REUTERS/Abdullah Rashid 

A view of a house for sale in the old city of Mosul, Iraq June 30, 2019. Picture taken June 30, 2019. REUTERS/Abdullah Rashid 

General view of the old city from the river side in Mosul, Iraq June 30, 2019. Picture taken June 30, 2019. REUTERS/Abdullah Rashid 

A general view from a hilltop shows the Sakhi Shrine and buildings in Kabul, Afghanistan June 21, 2019. Picture taken June 21, 2019. REUTERS/Saiyna Bashir 

A view shows churches and buildings in Bethlehem, in the Israeli-occupied West Bank June 17, 2019. Picture taken June 17, 2019. REUTERS/Raneen Sawafta 

Used single-serve coffee capsules are pictured at a recycling center in Bordeaux, France, April 2, 2019. REUTERS/Regis Duvignau 

Used single-serve coffee capsules are pictured at a recycling center in Bordeaux, France, April 2, 2019. REUTERS/Regis Duvignau 

Mining lamps are recharged in the mine "La Escondida" (The hidden one) in Villablino, Spain, December 27, 2018. Picture taken December 27, 2018. REUTERS/Eloy Alonso 

An outdoor toilet can be seen next to a house in the village of Papa Lealea located on the outskirts of Port Moresby in Papua New Guinea, November 19, 2018. Picture taken November 19, 2018. REUTERS/David Gray 

An insole from a shoe likely left by a migrant crossing the desert is seen in Pima County, Arizona, U.S., September 12, 2018. REUTERS/Lucy Nicholson 

Olive trees are seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

An olive tree is seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

An olive tree is seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

Olive trees are seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

An olive tree is seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

Olive trees are seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

An olive tree is seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

An olive tree is seen at a construction side of a pipeline in a grove of century-old olive trees in the southern Italian village of Melendugno, near Lecce, Italy November 9, 2018. REUTERS/Alessandro Garofalo 

A tomb is seen during All Saints Day at Alto de Sao Joao cemetery in Lisbon, Portugal November 1, 2018. REUTERS/Rafael Marchante 

Flowers are seen at a door of a tomb during All Saints Day at Alto de Sao Joao cemetery in Lisbon,, Portugal November 1, 2018. REUTERS/Rafael Marchante 

Leicester City football fans pay their respects outside the football stadium, after the helicopter of the club owner Thai businessman Vichai Srivaddhanaprabha crashed when leaving the ground on Saturday evening after the match, in Leicester, Britain, October 28, 2018. REUTERS/Peter Nicholls 

Old Chanares trees are seen at the Solor area next the Atacama desert, Chile, August 15, 2018. REUTERS/Ivan Alvarado 

A destroyed carriage is seen from a train traveling through the outskirts of Damascus towards recently opened international fair in Damascus, Syria, September 15, 2018. REUTERS/Marko Djurica SEARCH "SYRIA LIFE" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

The Arab Baths monument is seen flooded after heavy rain and flash floods hit Ronda, southern Spain, October 21, 2018. REUTERS/Jon Nazca 

A flood level mark is seen inside a house after heavy rain and flash floods hit Campillos, southern Spain, October 21, 2018. REUTERS/Jon Nazca 

A view of dry tree branches on the ground and the restoration works inside al-Zahir Baybars Mosque, an architectural landmark in old Cairo, Egypt October 16, 2018. Picture taken October 16, 2018. REUTERS/Amr Abdallah Dalsh 

Wheels from an old train carriage are seen in Harare, Zimbabwe, August 4, 2018. REUTERS/Siphiwe Sibeko SEARCH "SIBEKO TRAIN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Station master's office is seen at Marondera station in Mashonaland East, east of Harare, Zimbabwe, August 4, 2018. REUTERS/Siphiwe Sibeko SEARCH "SIBEKO TRAIN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Mold is shown in the house of a Marine and his family whose home suffered severe damage post-Hurricane Florence at Marine Corps Base Camp Lejeune, North Carolina, U.S., September 27, 2018. Picture taken September 27, 2018. REUTERS/Andrea Januta 

A cat sits in front of a retro car owned by retired mechanic Mikhail Krasinets at an open-air museum of Soviet-era vehicles in the village of Chernousovo, Tula region, Russia August 28, 2018. Picture taken August 28, 2018. REUTERS/Maxim Shemetov TPX IMAGES OF THE DAY