What's on this page?
1. The Pacific Ocean
Out of the five official oceans on this planet, the most polluted one is the Pacific Ocean.
Overall, sewage is the main culprit. Each year, 21,675 tonnes of BOD (Biochemical oxygen demand - the amount of oxygen required to remove waste and organic matter from water) enters these waters, along with 12,252 tonnes of suspended solids (such as decaying organic matter and particles).
Not only do these sewage spills destroy vulnerable habitats, they also impact local communities on nearby Pacific islands.
Here, you'll also find the infamous Great Pacific Garbage Patch. This plastic vortex of marine debris spans roughly 1.6 million square kilometres - or, in other words, an area twice the size of Texas or three times the size of France.
3. Yangtze River, China
The Yangtze River flows for 6,300 km, with its river basin stretching over almost a fifth of China's land area. Unfortunately, it's also one of the most polluted bodies of water on the planet.
The main sources of pollution here are industrial wastewater discharge (polluted water, generated from rainwater runoff and human activities) and agricultural chemical fertilizer - thanks to the factories and farms dotted along the riverbed. You'll also find various spots along the river covered in plastic waste.
The pollution levels here are so bad that nearby towns have been branded as 'cancer villages', with stomach, throat, and liver-related cancers affecting residents at a rate that's 2-3 times China's national average.
As for local ecosystems? Ancient animals are being pushed to extinction. The Chinese paddlefish, for example, has been around for more than 200 million years, but has been pushed to extinction in the last few decades because of the toxic waters.
4. Ganges River, India
Despite being India's holiest river - with locals regularly bathing in the water to wash away their sins - the Ganges has a big pollution problem.
Typically, the further down the Ma Ganga (Mother Ganges) you travel, the worse the quality of water gets. Winding over 1,500 miles, the holy river gradually transforms into a slurry of urban sewage, animal waste, pesticides, fertilizers, industrial metals, and ashes from cremated bodies.
Between them, homes and factories pump incredible amounts of wastewater into the river each day.
According to Reuters, if just one day's worth of wastewater pumped into the river was packed into half litre soda bottles, they would stretch to the moon and back nearly four times. Alternatively, if a day's worth of the Ganges waste was formed into a cube, it would be twice the height of the Statue of Liberty.
Summary
This list paints quite a bleak picture: toxic levels of pollution, declining fish populations, and water shortages for local communities.
But things can change.
If stricter laws are put in place to stop agricultural and industrial industries from dumping waste into bodies of water, then these oceans, rivers, and lakes will transform into the thriving ecosystems they once were.
Governments also need to support local communities and put sufficient waste systems in place, to make sure they don't have to either burn their items or toss them into these bodies of water.
It can be done - it just comes down to whether governments are willing to act fast enough.
Beth Howell Writer