A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

North Korean women in colorful traditional dresses are surrounded by flower blossoms known as “Kimilsungia” as they wait to guide guests at a flower exhibition in Pyongyang, North Korea, April 14, 2014. The flowers, named after Kim Il Sung, are on display to celebrate the late leader's official birth date of April 15, 1912. (Photo by David Guttenfelder/AP Photo)

A participant runs on stairs during a vertical run event at China World Summit Wing hotel in Beijing, China, September 19, 2015. About 800 runners took part in the event on Saturday, which takes runners up 82 floors, covering a total of 2,041 steps to a height of 330 metres, the organizer said. (Photo by Kim Kyung-Hoon/Reuters)

Participants hang from ropes as they learn how to use safety gears at an experience centre for construction safety training in Beijing, September 5, 2014. The centre which opened in June 2014 was established to educate workers about construction safety. According to the centre, about 1,000 construction workers undergo 3-hour classes which comprises of 33 modules every month. (Photo by Kim Kyung-Hoon/Reuters)

Chinese artist Kong Ning poses in a costume symbolizing a butterfly, which is decorated with 365 masks on its wings to represent the number of days in a year, during her performance art at the Badaling section of the Great Wall on the outskirts of Beijing January 1, 2015. Kong, whose works include themes related to China's air pollution problem, named her new performance art “Hua Die” (transforming into a butterfly) and performed it on the first day of the new year as she hopes that China has clean air for this year. (Photo by Kim Kyung-Hoon/Reuters)

A dachshund dressed as a leo walks a podium during a dachshund parade festival in St. Petersburg, Russia, Saturday, September 16, 2023. (Photo by Dmitri Lovetsky/AP Photo)

Agricultural workers are rice-transplanting at the Namsa Co-op Farm of Rangnang District in Pyongyang, DPRK, on Tuesday, May 25, 2021. (Photo by Jon Chol Jin/AP Photo)

Enya Kim from the Natural History department at auctioneers Bonhams & Butterfields stands in front of one of the world's largest set of shark jaws comprised of about 180 fossil teeth from the prehistoric species, Carcharocles megalodon, which grew to the size of a school bus, at the Venetian Resort Hotel Casino September 30, 2009 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)