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)

Los Angeles Chargers wide receiver Keenan Allen runs onto the field before an NFL football game against the Pittsburgh Steelers, Sunday, November 21, 2021, in Inglewood, Calif. (Photo by Ashley Landis/AP Photo)

A combine harvester drives over a field of cut grass and threshes lawn seeds from the dried plants in Hanshagen, Germany, Thursday, June 30, 2022. In Mecklenburg-Western Pomerania, the harvest has started earlier than usual due to the heat. (Photo by Jens Büttner/dpa via AP Photo)

A child covered in mud on Lake Chokrak near the village of Kurortnoye, Leninsky District of Crimea in Russia on July 4, 2019. (Photo by Sergei Malgavko/TASS)

Firefighters extinguish a fire in Kampar, Riau province on Indonesia's Sumatra island on August 13, 2019. Indonesian authorities are deploying thousands of extra personnel to prevent a repeat of the 2015 fires, which were the worst for two decades and choked the region in haze for weeks. (Photo by Wahyudi/AFP Photo)

Workers inflate and secure giant helium balloons which will be a featured part of tomorrow's 97th annual Macy's Thanksgiving Day Parade in New York, New York, USA, 22 November 2023. The annual parade will feature 16 giant character helium balloons which will be lead down the street by teams of people. (Photo by Justin Lane/EPA)

People attend in costume the 2022 New York Comic Con, at the Jacob Javits Convention Center in Manhattan in New York City, New York, U.S., October 6, 2022. (Photo by Brendan McDermid/Reuters)

Actresses Zelda Williams and Kelly Monaco attend Nintendo's celebration of the launch of Super Mario 3D Land at Siren Studios on November 3, 2011 in Hollywood, California. (Photo by Jason Merritt/Getty Images for Nintendo)