I would expect that mining, leather-producing and dye-producing areas may very well have seen similar types of toxic waste leading to negative health outcomes even before large scale industrialization. And the areas downstream.

Here's an example of a mine that has had toxic runoff likely for millenia: https://en.wikipedia.org/wiki/Rio_Tinto_(river) at least partly due to human mining activity. I would expect that people living downstream of the mine would have negative health outcomes, possibly without being aware.