Labourers work at the installation site of Liquefied Petroleum Gas (LPG) pipeline on May Day or Labour Day in Chandigarh, India, May 1, 2015. (Photo by Ajay Verma/Reuters)

In this photo taken on Thursday, July 23, 2015 migrants enter a train to Serbia at the railway station in the southern Macedonian town of Gevgelija. The country has become a major transit route for thousands of Middle Eastern and African refugees and migrants who cross over from Greece and then continue into Serbia. (Photo by Boris Grdanoski/AP Photo)

Participants take pictures of themselves as others run past the Tiananmen gate during the Beijing Marathon in Beijing, China, September 17, 2016. (Photo by Damir Sagolj/Reuters)

Russia's Ekaterina Birlova casts a shadow on the sand as she serves to Poland during a women's beach volleyball match at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, August 9, 2016. (Photo by Marcio Jose Sanchez/AP Photo)

Children dressed up as Hindu Lord Krishna pose during Janmashtami festival celebrations marking the birth anniversary of Krishna in Agartala, India August 24, 2016. (Photo by Jayanta Dey/Reuters)

Rohingya refugees stand outside of their refugee camp on February 11, 2017 in Medan, North Sumatra, Indonesia. Thousands of Rohingya Muslims have been stuck in limbo at Indonesia's refugee camps as the plight of Myanmar's ethnic minority continues. (Photo by Ulet Ifansasti/Getty Images)

A Haitian woman lies in a trance during a voodoo ceremony in Souvenance, a suburb of Gonaives, 171 km north of Port- au- Prince, on April 16, 2017. Haitian voodoo followers arrived in Souvenance to take part in the voodoo ceremonies held during Easter weekend. (Photo by Hector Retamal/AFP Photo)

A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)