Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

Rohingya refugee sisters Nur Kaida (R) and Ruhana hug each other at their shelter at the Palongkhali refugee camp near Cox's Bazar, Bangladesh December 21, 2017. (Photo by Marko Djurica/Reuters)

Chinese model Ming Xi falls down on runway during the 2017 Victoria's Secret Fashion Show at Mercedes-Benz Arena on November 20, 2017 in Shanghai, China. (Photo by VCG/VCG via Getty Images)

Bicycles of various bike-sharing services are seen at an urban village in smog during a polluted day in Shanghai, 2017. Rapid expansion of shared bicycle companies across China has led to massive piles of abandoned bikes as supply outstrips demand. (Photo by Aly Song/Reuters)

In this picture taken late on June 13, 2017, physiotherapist Masayuki Ozaki takes a bath with his silicone s*x doll Mayu at a love hotel in Yachimata, Chiba prefecture. Around 2,000 of the life- like dolls – which cost around 6,000 USD and come with adjustable fingers, removable head and life- like genitals – are sold each year in Japan, according to industry insiders. (Photo by Behrouz Mehri/AFP Photo)

Jessie Jo Stark and Bella Hadid attend Chrome Hearts X Bella Hadid Collaboration Launch as part of Paris Fashion Week at Chrome Hearts on March 4, 2017 in Paris, France. (Photo by Julien M. Hekimian/Getty Images for Chrome Hearts)

View of the Villarrica volcano taken from Pucon, some 800 kilometres south of Santiago, showing signs of activity on December 06, 2017. (Photo by Christian Miranda/AFP Photo)

A grey seal basks under a rainbow on a beach on the Lincolnshire coast, England on November 21, 2017. (Photo by Sean Weekly/Caters News Agency)