It is not only the mill that is a serious polluter, there are also many iron mines working which adds to the pollution. The largest open pit iron mine in Europe is there and it is very very big. The iron ore they dig out has a high level of radioactivity which is a contributor to cancer rates in the city.
I don't think they can do much to fix the issue.
Shutting it down fixes the issue and that’s the point. Another way of saying “nice mill you got there. shame if anything happened to it”