Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

Maharashtrian women dressed in traditional costumes attend celebrations to mark the Gudi Padwa festival in Mumbai March 21, 2015. The festival marks the beginning of the new year for Maharashtrians and is celebrated widely in Maharashtra and in the Konkan region. (Photo by Danish Siddiqui/Reuters)

An election poster calling for the legalisation of marijuana and featuring internet meme “Grumpy Cat” hangs outside the Pirate Party's campaign headquarters in Berlin on August 16, 2013. The Pirates, who to everyone's surprise were elected into Berlin's regional parliament in September 2011, are trying to capitalise on their recent electoral gains in upcoming parliamentary elections, running on a platform of transparency in government. Germany goes to the polls on September 22, 2013. Placard reads: “Hurry up, my dope is everything”. (Photo by John Macdougall/AFP Photo)

Protestor Bill Maloney (L) shouts during a live TV broadcast by BBC News Channel chief political correspondent Norman Smith after earlier forcing Deputy Prime Minister Nick Clegg to abandon a photocall near Parliament on March 19, 2014 in London, England. The Chancellor of the Exchequer, George Osborne has delivered his Budget statement to Members of Parliament in the House of Commons. (Photo by Peter Macdiarmid/Getty Images)

A man photographs Anila Quayyum Agha's “Intersections” art work on the first day of ArtPrize at the Grand Rapids Art Museum in Grand Rapids, Mich. on Wednesday, September 24, 2014. (Photo by Emily Rose Bennett/AP Photo/The Grand Rapids Press)

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)

Kendall Jenner and Kylie Jenner seen in this celebrity social media picture on September 1, 2016. (Photo by XposurePhotos.com)

Paramilitary policemen carry tyres as they take part in a training session in Zhangye, Gansu Province, China, March 1, 2016. (Photo by Reuters/Stringer)