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)

A Palestinian father evacuates his wounded daughter from the rubble of a destroyed house after an Israeli air strike in Gaza City, 16 May 2021. A total of 174 people have been killed in Israeli raids on Gaza, including 47 children and 29 women, the Palestinian Ministry of Health said on Sunday. In response violent confrontations between Israeli security forces and Palestinians in Jerusalem, various Palestinian militant factions in Gaza launched rocket attacks on Israel since 10 May, resulting in retaliatory strikes by Israel on Gaza. (Photo by Haitham Imad/EPA/EFE)

Palestinians inspect a destroyed street after an Israeli strike in Gaza City, 13 May 2021. In response to days of violent confrontations between Israeli security forces and Palestinians in Jerusalem, various Palestinian militants factions in Gaza launched rocket attacks since 10 May that killed at least six Israelis to date. Gaza Strip's health ministry said that at least 65 Palestinians, including 13 children, were killed in the recent retaliatory Israeli airstrikes. Hamas confirmed the death of Bassem Issa, its Gaza City commander, during an airstrike. (Photo by Mohammed Saber/EPA/EFE)

A woman wears a mask while carrying a dog in the street on January 22, 2020 in Wuhan, Hubei province, China. A new infectious coronavirus known as “2019-nCoV” was discovered in Wuhan as the number of cases rose to over 400 in mainland China. Health officials stepped up efforts to contain the spread of the pneumonia-like disease which medicals experts confirmed can be passed from human to human. The death toll has reached 17 people as the Wuhan government issued regulations today that residents must wear masks in public places. Cases have been reported in other countries including the United States, Thailand, Japan, Taiwan, and South Korea. (Photo by Getty Images/China Stringer Network)

A man runs away during a police round up of suspected drug addicts in Kabul, Afghanistan December 27, 2015. Afghan officials have opened a new drug treatment centre in an abandoned NATO military base in Kabul, in the latest attempt to stamp out the country's massive problem of drug abuse. Camp Phoenix, a former training camp on the edges of Kabul set up by the U.S. army in 2003, will take in around 1,000 homeless drug addicts who will receive food, medical attention and treatment, said Public Health Minister Ferozuddin Feroz. (Photo by Ahmad Masood/Reuters)

A Filipino woman wears a mask to try and protect against the spread of coronavirus in Malate district, Manila City on March 24, 2020. The Philippines has taken drastic measures to combat the spread of Covid-19. The entire country is under strict quarantine and the army is on the streets to monitor compliance. According to official figures, there are 462 positive cases and 33 dead in the Philippines, but it is thought that thousands of cases remain undetected due to lack of resources in a country where millions of people have no access to health care. In the poorest and most crowded areas, it’s almost impossible to adhere to the physical distancing required during quarantine. (Photo by Alejandro Ernesto/The Guardian)

In this April 27, 2020 photo, a health worker helps another as she fainted because of exhaustion and long working hours during a swab test drive for COVID 19, in New Delhi, India. Two and a half months of nationwide lockdown kept numbers of infections relatively low in India. But with restrictions easing in recent weeks, cases have shot up, raising questions about whether authorities have done enough to avert catastrophe. Half of Delhi’s 8,200 hospital beds dedicated to COVID-19 patients are already full and officials are projecting more than half a million cases in the city alone by July 31. (Photo by Manish Swarup/AP Photo)

Palestinian members of Gaza's Bar Woolf sports team perform with fire above the ruins of a building destroyed in recent Israeli air strikes, in Beit Lahia, on May 26, 2021. A ceasefire was reached late last week after 11 days of deadly violence between Israel and the Hamas movement which runs Gaza, stopping Israel's devastating bombardment on the overcrowded Palestinian coastal enclave which, according to the Gaza health ministry, killed 248 Palestinians, including 66 children, and wounded more than 1,900 people. Meanwhile, rockets from Gaza claimed 12 lives in Israel, including one child and an Israeli soldier. (Photo by Mahmud Hams/AFP Photo)