Kodak kept very precises figures on the health of its workers and they kept statistics on us as well. I had blood tests every 6 months while doing chemical work in the lab. The results showed that there was no statistical difference between EK workers and those anywhere else. No bumps in cancers or in skin rashes! Yes, I have seen rashes in photographic circles, but I saw poinson ivy with boy scouts!
As for ecological impact, take a look at what can be done with a landfill with a little effort!