People walk and sit on the beach during foggy weather amid the coronavirus disease (COVID-19) outbreak in the coastal town of Ostend, Belgium February 27, 2021. REUTERS/Yves Herman

People walk and sit on the beach during foggy weather amid the coronavirus disease (COVID-19) outbreak in the coastal town of Ostend, Belgium February 27, 2021. REUTERS/Yves Herman

People walk and sit on the beach during foggy weather amid the coronavirus disease (COVID-19) outbreak in the coastal town of Ostend, Belgium February 27, 2021. REUTERS/Yves Herman

Children play on the beach during foggy weather amid the coronavirus disease (COVID-19) outbreak in the coastal town of Ostend, Belgium February 27, 2021. REUTERS/Yves Herman

A woman walks along the Spit of Vasilievsky Island on a foggy morning in central Saint Petersburg, Russia February 25, 2021. REUTERS/Anton Vaganov

Janet Farbstein heads to her vaccination appointment in Foggy Bottom West End Village in Washington, U.S., February 3, 2021. Picture taken February 3, 2021. REUTERS/Kevin Fogarty

Janet Farbstein heads to her vaccination appointment in Foggy Bottom West End Village in Washington, U.S., February 3, 2021. Picture taken February 3, 2021. REUTERS/Kevin Fogarty

Janet Farbstein heads to her vaccination appointment with assistance from Bill Wicker, a volunteer for Foggy Bottom West End Village, in Washington, U.S., February 3, 2021. Picture taken February 3, 2021. REUTERS/Kevin Fogarty

A railway labourer walks on a bridge near the railway tracks during a foggy day in New Delhi, India, January 16, 2021. REUTERS/Anushree Fadnavis

A traffic police officer stops vehicles for a convoy to pass on a foggy morning in New Delhi, India, January 16, 2021. REUTERS/Anushree Fadnavis

Homeless men sit around a bonfire on a foggy morning in the old quarters of Delhi, India, January 15, 2021. REUTERS/Anushree Fadnavis

A homeless man sleeps on the banks of the river Yamuna on a foggy morning in New Delhi, India, January 15, 2021. REUTERS/Anushree Fadnavis

A homeless man on a wheelchair is seen on the banks of the river Yamuna on a foggy morning in New Delhi, India, January 15, 2021. REUTERS/Anushree Fadnavis

Homeless people rest under a tree on the banks of the river Yamuna on a foggy morning in New Delhi, India, January 15, 2021. REUTERS/Anushree Fadnavis

Indian National Security Guard (NSG) commandos take part in the rehearsal for the Republic Day parade on a foggy morning in New Delhi, India, January 14, 2021. REUTERS/Anushree Fadnavis

Indian National Security Guard (NSG) commandos take part in the rehearsal for the Republic Day parade on a foggy morning in New Delhi, India, January 14, 2021. REUTERS/Anushree Fadnavis TPX IMAGES OF THE DAY

Men exercise at a park on a foggy winter morning in New Delhi, India, January 4, 2021. REUTERS/Adnan Abidi

A person is seen silhouetted with the City of London financial district in the background on a foggy day, as the spread of the coronavirus disease (COVID-19) continues, in London, Britain January 1, 2021. REUTERS/Hannah McKay

A general view of the City of London financial district on a foggy day, as the spread of the coronavirus disease (COVID-19) continues, in London, Britain January 1, 2021. REUTERS/Hannah McKay

Skiers are seen during foggy weather at the Corviglia ski area, as the spread of the coronavirus disease (COVID-19) continues, in the Alpine resort of St. Moritz, Switzerland December 11, 2020. REUTERS/Arnd Wiegmann

A boat is seen on a foggy morning near the Padma Bridge which is under construction over its river in Munshiganj, Bangladesh, December 10, 2020. REUTERS/Mohammad Ponir Hossain

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

A swimmer enters the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

A swimmer leaves the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

A swimmer enters the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls TPX IMAGES OF THE DAY

A man swims in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

A swimmer enters the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

A swan beats its wings alongside Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

People swim in the Serpentine Lake in Hyde Park during cold and foggy weather, in London, Britain, December 8, 2020. REUTERS/Henry Nicholls

A man walks on a road in a foggy weather near Sofia, Bulgaria, December 8, 2020. REUTERS/Stoyan Nenov

Farmers arrive to attend a protest during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers shout slogans at a protest site during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers attend a protest during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

A farmer ties his turban as he gets ready to attend a protest during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers cover themselves with blankets at the site of a protest during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers shout slogans at a protest site during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

A farmer sleeps under a tractor trolley at the site of a protest during a nationwide strike against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

A farmer prepares meals at the site of a protest during a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers bathe as they get ready to attend a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers arrive to attend a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers attend a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers attend a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers shout slogans as they attend a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

A member of the Rapid Action Force (RAF) walks next to barricades at the site of protest during a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Policemen stand at the site of protest during a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Farmers gather to attend a nationwide protest against the newly passed farm bills on a foggy morning at Singhu border near Delhi, India, December 8, 2020. REUTERS/Danish Siddiqui

Christmas lights are seen in Eyre Square in the city centre during foggy weather in Galway, Ireland, December 7, 2020. REUTERS/Clodagh Kilcoyne

Christmas lights are seen as shoppers walk through the city centre during foggy weather in Galway, Ireland, December 7, 2020. REUTERS/Clodagh Kilcoyne

Christmas lights are seen as shoppers walk through the city centre during foggy weather in Galway, Ireland, December 7, 2020. REUTERS/Clodagh Kilcoyne

People take pictures inside a Christmas decoration in the city centre during foggy weather in Galway, Ireland, December 7, 2020. REUTERS/Clodagh Kilcoyne

Christmas lights are seen as shoppers walk through the city centre during foggy weather in Galway, Ireland, December 7, 2020. REUTERS/Clodagh Kilcoyne

Christmas lights are seen as shoppers walk through the city centre during foggy weather in Galway, Ireland, December 7, 2020. REUTERS/Clodagh Kilcoyne

Skyscrapers in the City of London financial district are seen on a foggy morning, with Leadenhall market in the foreground, amid the spread of the coronavirus disease (COVID-19), London, Britain, December 7, 2020. REUTERS/Toby Melville

Skyscrapers in the City of London financial district are seen on a foggy morning, amid the spread of the coronavirus disease (COVID-19), London, Britain, December 7, 2020. REUTERS/Toby Melville

Skyscrapers in the City of London financial district are seen on a foggy morning, with the HMS Belfast in the foreground, amid the spread of the coronavirus disease (COVID-19), London, Britain, December 7, 2020. REUTERS/Toby Melville