A LOT of different drugs are thrown down the toilet all over the world. Or just thrown into water in some places, I would assume.
And that's not to mention all the industrial pollutants that certainly haven't all gone away (or been processed by zebra mussels) since Western industry was moved to china ....
General contamination of water is the problem in general. Humans have treated waterways like free disposal units for millenia.
A LOT of different drugs are thrown down the toilet all over the world. Or just thrown into water in some places, I would assume.
And that's not to mention all the industrial pollutants that certainly haven't all gone away (or been processed by zebra mussels) since Western industry was moved to china ....
General contamination of water is the problem in general. Humans have treated waterways like free disposal units for millenia.