The Yangtze alone pours up to an estimated 1.5 million metric tons into the Yellow Sea.
Schmidt and his colleagues dug up published data on the plastic concentration in 57 rivers of various sizes around the world. These measurements included bottles and bags, as well as microscopic fibers and beads. The researchers multiplied these concentrations by the rivers’ water discharge to calculate the total weight of plastic flowing into the sea. They then fed these data into a model that compared them with the estimated weight of plastic litter generated per person per day along each river.