I have a 200k city and environnement degradate even if no mine or factory created...
I destroyed some factory and mines but the pollution is still here.
I added lot of tress and parks but it didn't help.
What can i do to save my town?
PS: maybe add some research to lower factories pollution
as far as i know, trees or parks have no impact on pollutions, tho i made sugestion that parks get some montly maintanance fee and have some minor impact on it.
also if i remember correct, if there is houses or residental buildings next to factories/mines etc, have very big impact on enviroment.
also, if you stockpile factories without space between them they have bigger impact too, but if im not wrong in latest release its changed that how close they are to each other didnt matter anymore.
only suggestion that comes in mind is to relocate some industry in other city, or scater factories around, and keep houses and residental away from them.