If you want to do this the source of the pollution is clear.
This study goes into some of the sources - they write that 90% of the pollution comes from river sources: the Yangtze, the Indus, Yellow River, Hai River, the Nile, the Ganges, Pearl River, Amur River, the Niger, and the Mekong. All of those are either Asian or African and they mostly empty into the Pacific. For the Atlantic there is
great evidence that almost all of that comes from Chinese ship dumping.
Want to stop this? Bottle up the sources in India and China.