Pedestrians cover their face as they walk along the dusty road in Kathmandu, Nepal February 27, 2017. Nepal has forced 2,500 old vehicles off roads in its capital city of Kathmandu, part of a fight against alarming air pollution levels that have hit nine times World Health Organisation (WHO) limits. Air pollution has been a chronic problem in rapidly growing Kathmandu, which sits in a Himalayan valley and is home to more than 3mn people. (Photo by Navesh Chitrakar/Reuters)

Actresses perform during the Olympic flame lighting ceremony for the Paris 2024 Olympics Games at the Ancient Olympia archeological site, birthplace of the ancient Olympics in southern Greece, on April 16, 2024. (Photo by Angelos Tzortzinis/AFP Photo)

A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

A woman sandboards on the mountain in Wadi el-Rayan Fayoum, Egypt, November 18, 2016. (Photo by Mohamed Abd El Ghany/Reuters)

Egyptian riot police charge towards protesters near Egypt's Interior Ministry, as violent demonstrations continued into their second day on February 3, 2012 in central Cairo, Egypt. (Photo by Ed Giles/Getty Images)

A worker looks on with his camel as he waits for tourists at the Giza Pyramids on the outskirts of Cairo, Egypt, November 8, 2015. Egypt's Tourism Minister Hesham Zaazou said Cairo regretted the suspension of flights and was doing all it could to secure its airports and tourist sites, adding that he would fly to Sharm al-Sheikh to oversee measures to support tourists there. (Photo by Amr Abdallah Dalsh/Reuters)

Tourists are visiting Pingyao Ancient City in Shanxi Province, China, on July 9, 2024. (Photo by Costfoto/NurPhoto/Rex Features/Shutterstock)

A man sleeps between tombstones in front of his single-room home on a hot night in the Cairo Necropolis, Egypt, October 13, 2015. In the sprawling Cairo Necropolis, known as the City of the Dead, life and death are side by side. Amid a housing crisis in Egypt, and with the population of greater Cairo estimated at about 20 million, people count themselves lucky to have a place to call home in the graveyards that date back hundreds of years. (Photo by Asmaa Waguih/Reuters)