Instead, we focus on the US. 
Just ten rivers are responsible for up to 95% of all river-borne plastic trash that ends up in the sea. Silver lining: cleaning them up would have a huge positive impact.
Cheap, durable and multifunctional, plastic is one of humanity’s most successful inventions. From the 1950s to 2015, we’ve produced 8.3 billion metric tons of the stuff. By now, it’s everywhere. It’s also non-biodegradable. And that’s devastating the environment. Only 9% of all plastic waste has been recycled, and another 12% has been incinerated. That means that almost 80%—nearly 6.3 billion tons—has turned into waste with no half-life to speak of: condemned to an eternity as landfill, litter or ocean-clogging junk.
Every year, plastic kills around 1 million seabirds, 100,000 sea mammals and inestimable numbers of fish. The volume of plastic trash in the world’s oceans is currently estimated to be around 150 million tons. No less than eight million tons are added to that every year—that’s one truckload every minute. Between 0.5 and 2.75 million tons come from rivers alone.
Large rivers are particularly efficient conveyors of plastic waste to the oceans, especially in countries lacking a well-developed waste management infrastructure. Up to 95% of river-borne plastic comes from just 10 rivers, scientists at the Helmholtz Center for Environmental Research in Leipzig, Germany have found.
The scientists analysed data on both microplastic debris (<5mm) such as beads and fibres, as well as microplastic objects (plastic bottles, bags, etc.) from 79 sampling sites on 57 of the world’s largest rivers, singling out the 10 mapped out here as the biggest culprits, due to “mismanagement of plastic waste in their watersheds”.
https://bigthink.com/strange-maps/these-10-rivers-carry-95-of-all-plastic-into-the-ocean