There are only 10 rivers responsible for polluting the world’s oceans with up to four million tons of plastic annually, according to a newly-published study.
These rivers — eight of which are in Asia — account to 88-95% of the global plastic load into the sea.
The polluting rivers are found in the Amazon, mostly in Brazil; the Cross between Cameroon and Nigeria; the Huanpu, Xi and Yangtze in China; the Brantas and Solo in Indonesia; the Irrawaddy in Myanmar; and the Pasig in the Philippines, according to Cosmos Magazine.
The latter computed plastic load inputs from 40,760 watersheds into the ocean using geospatial data on population density, and mismanaged plastic waste (MPW) production per inhabitant and per day in 182 countries.
It found that between 1.15 and 2.41 million tons of plastic is transported to the seas.
Researchers from the Hemholtz Center for Environmental Research and the Weihenstephan-Triesdorf University of Applied Science in Germany analyzed 79 sampling sites along 57 rivers around the world, Phys.org noted.
They acknowledged the challenge in arriving at more precise estimations due to unknown variables, such as the “missing plastic” problem, which basically refers to the mismatch between the estimation of inputs to the sea and the actual amount observable.
Researchers estimated that halving plastic input from the top 10 rivers could lower the total contribution of all rivers by 45%.