Oct. 11 (UPI) -- The problem of plastic pollution in the ocean is much talked about. But where does all that garbage come from? How do plastics from inland cities make their way into the ocean?
In setting out to answer those questions, a team of researchers decided to identify 10 rivers around the world where plastic waste mismanagement is most severe. The scientists detailed the 10 biggest plastic polluters in a new paper published this week in the journal Environmental Science & Technology.
The myth of giant floating patches of garbage has sometimes overshadowed the reality of plastic pollution in the ocean. There are garbage patches, but much of the debris consists of tiny plastic particles suspended in the ocean. Until now, scientists didn't have a detailed understanding of how high concentrations of micro plastics move from inland rivers downstream into the ocean.
The new study promises to fill in the knowledge gap and retrace the microplastic concentration patterns.
Scientists in Germany surveyed dozens of studies on plastic pollution, including data collected from 79 sampling sites along 57 rivers. They discovered a strong link between poor plastic waste management practices and high concentrations of plastics in local waterways.
The analysis of Christian Schmidt -- researcher at the Helmholtz-Centre for Environmental Research in Leipzig -- and his colleagues showed just 10 rivers are responsible for 88 to 95 percent of plastic pollution in the ocean. Eight of the 10 rivers are in Asia.
Cutting plastic pollution in the ten listed rivers could reduce plastic pollution in the ocean by as much as 45 percent. Because collecting microplastic particles from the ocean is nearly impossible, researcher say the only ways to curb microplastic pollution is the stop it at its source and intercept it along its route to the ocean.