A man pours mud water on the head of his girl friend during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Friday, July 18, 2014. The annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

Members of the Colombian Navy stand guard on top of a seized submarine built by drug smugglers in a makeshift shipyard in Timbiqui, department of Cauca February 14, 2011. Colombian authorities said the submersible craft was to be used to transport 8 tons of cocaine illegally into Mexico. (Photo by Jaime Saldarriaga/Reuters)

English fashion designer Mary Quant (R) with a group of models at Heathrow Airport, before leaving for a continental fashion tour, 18th March 1968. (Photo by Express/Getty Images)

A worker carries a basket of fish, at a wholesale fish market, on the outskirts of Kolkata, March 15, 2017. (Photo by Rupak De Chowdhuri/Reuters)

A South China Tiger cub meets public at Guangzhou Zoo on June 22, 2017 in Guangzhou, Guangdong Province of China. Guangzhou Zoo boasts of the successful breeding of South China Tiger cub after 15 years. (Photo by VCG/VCG via Getty Images)

A child plays in front of “Etnias”, a large graffiti wall by Brazilian graffiti artist Eduardo Kobra created ahead of the Rio 2016 Olympic Games at Porto Maravilha in Rio de Janeiro, Brazil, 30 July 2016. The Olympics start on 05 August. Eduardo Kobra hopes to set a Guinness World Record for the largest graffiti created by a single artist. (Photo by Lukas Coch/EPA)

A ladyboy sеx worker wears a belt with a dollar sign on it while holding condoms and lube handed to her by Sisters, a transgendered outreach and community services organization in Pattaya, Thailand on August 25, 2016. Many of Thailand's ladyboys live in Pattaya, a large percentage of whom work in the sеx industry there. (Photo by Aaron Joel Santos/Getty Images/Aurora Creative)