Nation One of the most plastic-polluted rivers in the world is in Tennessee, and someone swam through it February 11, 2019Andrew Capps, Knoxville News SentinelComments Off on One of the most plastic-polluted rivers in the world is in Tennessee, and someone swam through it A new report following the 34-day swim of the Tennessee River found that its microplastic levels measured worse than rivers in China and Europe.