In this Monday, March 16, 2015 photo, Syrian refugee Samira Helal, 17, who is two months pregnant, poses for a portrait at inside her tent at an informal tented settlement near the Syrian border, on the outskirts of Mafraq, Jordan. Nearly 3.8 million Syrians have fled their country and are now registered as refugees, according to the U.N. Most face increasingly desperate circumstances. (Photo by Muhammed Muheisen/AP Photo)

In this March 18, 2015 photo, Andrea, better known as Loira, which is the Portuguese word for “blonde”, poses for a portrait in an open-air crack cocaine market, known as a “cracolandia” or crackland where users can buy crack, and smoke it in plain sight, day or night, in Rio de Janeiro, Brazil. Andrea says she is married and has a home, but she keeps returning to crackland to feed her addiction. (Photo by Felipe Dana/AP Photo)

The front wheels of a tractor, pulling a trailer overloaded with sugarcane, are seen lifted off the ground as it passes through the streets of Karor Lan Esan, Pakistan December 6, 2015. (Photo by Caren Firouz/Reuters)

“Left behind” children Luo Hongni, 11 (L) and brother Luo Gan,10, carry flowers to be used as feed while doing chores in the fields on December 18, 2016 in Anshun, China. Like millions of Chinese children, the four Luo siblings are being raised by their grandparents in rural China as their parents left to find work in urban areas. (Photo by Kevin Frayer/Getty Images)

People enjoying the races on a wet day at Chester Racecourse on May 12, 2017 in Chester, England. (Photo by Alan Crowhurst/Getty Images)

An Indian nomadic Gujjar girl hangs on to a horse cart after collecting bricks from debris on the outskirts of Jammu, India, Tuesday, March 7, 2017. The Gujjar tribal communities are considered by some to be economically and socially backward and the lack of care by the state government has led to resentment amongst the community. The tribe moves to the plains from the hills to escape the cold winters. (Photo by Channi Anand/AP Photo)

Mazouza Bouglada, 86, a berber woman from the Chaouia region, who has facial tattoos, poses for a photograph in Taghit in the Aures Mountain, Algeria October 8, 2015. Bouglada was tattooed aged 7 by a nomadic man from the Sahara region. She was advised by her mother to get tattooed. The more she got tattooed the more she showed off. Even if she still remembers the pain, she felt beautiful once it was done, Bouglada said. She was very proud of her stars on her cheeks. Her eldest sister had been tattooed before her and she wanted to imitate her. Bouglada said she has now given away all her silver jewellery to atone for the sin that believers told her she had committed by being tattooed. (Photo by Zohra Bensemra/Reuters)

A Palestinian protester uses a sling shot to throw stones towards Israeli security forces during clashes on the Israeli border Eastern Gaza City, Friday, November 6, 2015. (Photo by Adel Hana/AP Photo)